Comparison of the structure of (E)-2-(2-benzylidenehydrazinylidene)quin­oxaline with those of its chloro- and bromobenzylidene analogues

(E)-2-(2-Benzylidenehydrazinylidene)quin­oxaline, C₁₅H₁₂N₄, crystallized with two molecules in the asymmetric unit. The structures of six halogen derivatives of this compound were also investigated: (E)-2-[2-(2-chlorobenzylidene)hydrazinyl­idene]quinoxaline, C₁₅H₁₁ClN₄; (E)-2-[2-(3-chlorobenzylidene)hydrazinylidene]quinoxaline, C₁₅H₁₁ClN₄; (E)-2-[2-(4-chlorobenzylidene)hydrazinylidene]quinoxaline, C₁₅H₁₁ClN₄; (E)-2-[2-(2-bromobenzylidene)hydrazinylidene]quinoxaline, C₁₅H₁₁BrN₄; (E)-2-[2-(3-bromobenzylidene)hydrazinylidene]quino­xaline, C₁₅H₁₁BrN₄; (E)-2-[2-(4-bromobenzylidene)hydrazin­yl­idene]quinoxaline, C₁₅H₁₁BrN₄. The 3-Cl and 3-Br com­pounds are isomorphous, as are the 4-Cl and 4-Br compounds. In all of these compounds, it was found that the supramolecular structures are governed by similar predominant patterns, viz. strong intermolecular N-H...N(pyrazine) hydrogen bonds supplemented by weak C-H...N(pyrazine) hydro­gen-bond interactions in the 2- and 3-halo compounds and by C-H...Cl/Br interactions in the 4-halo compounds. In all compounds, there are [pi]-[pi] stacking interactions.

Computing details

For all compounds, data collection: CrystalClear-SM Expert 2.0 r13 (Rigaku, 2011); cell refinement: CrystalClear-SM Expert 2.0 r13 (Rigaku, 2011); data reduction: CrystalClear-SM Expert 2.0 r13 (Rigaku, 2011); program(s) used to solve structure: SHELXS (Sheldrick, 2008). Program(s) used to refine structure: OSCAIL (McArdle et al., 2004), SHELXL97 (Sheldrick, 2008) for (1), (2a), (2b), (3a); OSCAIL (McArdle et al., 2004), SHELXS97 (Sheldrick, 2008) for (2c); OSCAIL McArdle ( et al., 2004), SHELXL97 (Sheldrick, 2008) for (3b); OSCAIL (McArdle et al., 2004), SHELXL97 (Sheldrick, 2008) OLEX2, (Dolomanov et al., 2009) for (3c). For all compounds, molecular graphics: Mercury (Macrae, 2006). Software used to prepare material for publication: OSCAIL (McArdle et al., 2004), SHELXL97 (Sheldrick, 2008), PLATON (Spek ,2009)' for (1); OSCAIL (McArdle et al., 2004), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009) for (2a), (2b), (3a), (3c); OSCAIL (McArdle et al., 2004), SHELXS97 (Sheldrick, 2008), 'PLATON (Spek, 2009)' for (2c); OSCAIL (McArdle et al., 2004), SHELXL97 (Sheldrick, 2008), PLATON (Spek ,2009) for (3b).

Figures

(1) (E)-2-(2-(hydrazinyl)quinoxaline

Crystal data

C15H12N4	F(000) = 1040
Mr = 248.29	Dx = 1.357 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71075 Å
Hall symbol: -P 2ybc	Cell parameters from 3113 reflections
a = 6.483 (7) Å	θ = 2.9–27.5°
b = 21.36 (3) Å	µ = 0.09 mm^−1
c = 17.56 (2) Å	T = 100 K
β = 90.96 (3)°	Plate, yellow
V = 2431 (5) Å^3	0.13 × 0.08 × 0.01 mm
Z = 8

Data collection

Rigaku Saturn724+ (2x2 bin mode) diffractometer	5479 independent reflections
Radiation source: Rotating Anode	3106 reflections with I > 2σ(I)
Confocal monochromator	Rint = 0.080
Detector resolution: 28.5714 pixels mm^-1	θmax = 27.6°, θmin = 2.5°
profile data from ω–scans	h = −8→8
Absorption correction: multi-scan CrystalClear-SM Expert 3.1 b5 (Rigaku, 2011)	k = −27→26
Tmin = 0.989, Tmax = 0.999	l = −22→11
12637 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.149	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.370	H-atom parameters constrained
S = 1.21	w = 1/[σ^2(Fo^2) + (0.1238P)^2 + 2.6864P] where P = (Fo^2 + 2Fc^2)/3
5479 reflections	(Δ/σ)max < 0.001
343 parameters	Δρmax = 0.38 e Å^−3
0 restraints	Δρmin = −0.33 e Å^−3

Special details

Experimental. Special experimental details

Compound (1): m.p. 498–499 K. ¹H NMR (400 MHz, DMSO-d₆): δ 11.69 (1H, s, NH), 9.12 (1H, s, H3), 8.16 (1H, s, CH), 7.92 (1H, d, J = 8.2 Hz, H5), 7.77 (2H, d, J = 7.2 Hz, H2' and H6'), 7.70 (1H, dd, J = 8.2 and J = 2.0 Hz, H8), 7.67 (1H, t, J = 8.2 Hz, H7), 7.49 (1H, dt, J = 8.2 and J = 2.0 Hz, H6); 7.44 (2H, t, J = 7.2 Hz, H3' and H5'); 7.39 (1H, m, H4'). ¹³C NMR (100 MHz, DMSO-d₆): δ 150.3, 141.8, 140.9, 137.9, 136.4, 134.7, 130.3, 129.2, 128.8, 126.5, 126.1, 125.1. MS/ESI (M – H): 247.1.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1A	0.7490 (6)	0.0664 (2)	0.2295 (3)	0.0387 (11)
H1A	0.6255	0.0710	0.2488	0.046*
N2A	0.7784 (7)	0.0263 (2)	0.1701 (2)	0.0366 (10)
N11A	0.8709 (6)	0.1423 (2)	0.3100 (2)	0.0338 (10)
N14A	1.2779 (6)	0.1176 (2)	0.2642 (3)	0.0374 (11)
C3A	0.6185 (8)	−0.0034 (3)	0.1444 (3)	0.0398 (13)
H3A	0.4895	0.0022	0.1683	0.048*
C4A	1.2388 (8)	0.1641 (2)	0.3166 (3)	0.0360 (12)
C8A	1.0337 (8)	0.1764 (2)	0.3390 (3)	0.0344 (12)
C12A	0.9119 (8)	0.0995 (2)	0.2588 (3)	0.0352 (12)
C13A	1.1200 (8)	0.0867 (3)	0.2363 (3)	0.0363 (12)
H13A	1.1435	0.0547	0.1998	0.044*
C15A	1.4011 (8)	0.1993 (3)	0.3484 (3)	0.0394 (13)
H15A	1.5392	0.1904	0.3346	0.047*
C16A	1.3623 (9)	0.2460 (3)	0.3989 (3)	0.0429 (13)
H16A	1.4727	0.2704	0.4194	0.052*
C17A	1.1581 (8)	0.2583 (3)	0.4208 (3)	0.0420 (13)
H17A	1.1327	0.2910	0.4561	0.050*
C18A	0.9960 (8)	0.2244 (2)	0.3925 (3)	0.0364 (12)
H18A	0.8596	0.2329	0.4084	0.044*
C31A	0.6324 (8)	−0.0453 (2)	0.0796 (3)	0.0369 (12)
C32A	0.8206 (8)	−0.0522 (2)	0.0408 (3)	0.0383 (12)
H32A	0.9423	−0.0324	0.0597	0.046*
C33A	0.8266 (8)	−0.0883 (3)	−0.0251 (3)	0.0417 (13)
H33A	0.9516	−0.0916	−0.0523	0.050*
C34A	0.6512 (9)	−0.1193 (2)	−0.0516 (3)	0.0424 (13)
H34A	0.6569	−0.1443	−0.0962	0.051*
C35A	0.4697 (9)	−0.1139 (3)	−0.0130 (3)	0.0442 (14)
H35A	0.3508	−0.1358	−0.0307	0.053*
C36A	0.4583 (8)	−0.0765 (2)	0.0519 (3)	0.0386 (13)
H36A	0.3309	−0.0724	0.0773	0.046*
N1B	0.5632 (7)	0.0473 (2)	0.4258 (3)	0.0397 (11)
H1B	0.6889	0.0381	0.4114	0.048*
N2B	0.5319 (7)	0.0931 (2)	0.4788 (3)	0.0377 (11)
N11B	0.4338 (6)	−0.0241 (2)	0.3404 (2)	0.0366 (10)
N14B	0.0300 (7)	−0.0014 (2)	0.3931 (3)	0.0397 (11)
C3B	0.6922 (8)	0.1224 (3)	0.5034 (3)	0.0371 (12)
H3B	0.8246	0.1118	0.4850	0.044*
C4B	0.0636 (7)	−0.0459 (2)	0.3370 (3)	0.0343 (12)
C8B	0.2674 (8)	−0.0567 (2)	0.3112 (3)	0.0360 (12)
C12B	0.3968 (8)	0.0159 (2)	0.3955 (3)	0.0359 (12)
C13B	0.1921 (8)	0.0272 (3)	0.4214 (3)	0.0371 (12)
H13B	0.1730	0.0569	0.4610	0.045*
C15B	−0.1004 (8)	−0.0807 (2)	0.3053 (3)	0.0396 (13)
H15B	−0.2367	−0.0739	0.3224	0.047*
C16B	−0.0658 (8)	−0.1243 (3)	0.2500 (3)	0.0415 (13)
H16B	−0.1779	−0.1475	0.2290	0.050*
C17B	0.1353 (8)	−0.1348 (3)	0.2242 (3)	0.0401 (13)
H17B	0.1581	−0.1648	0.1853	0.048*
C18B	0.2992 (8)	−0.1020 (2)	0.2547 (3)	0.0373 (12)
H18B	0.4347	−0.1100	0.2374	0.045*
C31B	0.6707 (8)	0.1725 (2)	0.5602 (3)	0.0357 (12)
C32B	0.8431 (8)	0.2067 (2)	0.5831 (3)	0.0397 (13)
H32B	0.9742	0.1968	0.5630	0.048*
C33B	0.8257 (8)	0.2551 (3)	0.6351 (3)	0.0420 (13)
H33B	0.9437	0.2792	0.6487	0.050*
C34B	0.6367 (9)	0.2685 (3)	0.6674 (3)	0.0428 (13)
H34B	0.6257	0.3008	0.7043	0.051*
C35B	0.4637 (9)	0.2340 (2)	0.6453 (3)	0.0413 (13)
H35B	0.3335	0.2434	0.6665	0.050*
C36B	0.4804 (8)	0.1856 (2)	0.5919 (3)	0.0369 (12)
H36B	0.3623	0.1618	0.5776	0.044*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1A	0.031 (2)	0.044 (3)	0.041 (3)	−0.005 (2)	0.002 (2)	−0.008 (2)
N2A	0.037 (2)	0.040 (2)	0.033 (2)	0.005 (2)	−0.0049 (19)	0.0011 (19)
N11A	0.032 (2)	0.039 (2)	0.030 (2)	0.0001 (19)	−0.0043 (18)	−0.0045 (19)
N14A	0.033 (2)	0.043 (3)	0.036 (2)	0.005 (2)	−0.0061 (19)	0.000 (2)
C3A	0.034 (3)	0.048 (3)	0.037 (3)	−0.002 (3)	0.001 (2)	0.004 (3)
C4A	0.038 (3)	0.036 (3)	0.034 (3)	0.003 (2)	−0.002 (2)	0.000 (2)
C8A	0.035 (3)	0.041 (3)	0.027 (3)	0.007 (2)	−0.006 (2)	0.000 (2)
C12A	0.036 (3)	0.036 (3)	0.033 (3)	−0.009 (2)	−0.005 (2)	0.005 (2)
C13A	0.034 (3)	0.042 (3)	0.032 (3)	0.003 (2)	0.000 (2)	0.006 (2)
C15A	0.033 (3)	0.048 (3)	0.037 (3)	−0.003 (2)	−0.006 (2)	0.000 (3)
C16A	0.046 (3)	0.043 (3)	0.039 (3)	−0.007 (3)	−0.013 (3)	−0.004 (3)
C17A	0.045 (3)	0.041 (3)	0.039 (3)	0.003 (3)	−0.010 (3)	−0.005 (2)
C18A	0.040 (3)	0.033 (3)	0.036 (3)	−0.002 (2)	−0.002 (2)	0.003 (2)
C31A	0.045 (3)	0.033 (3)	0.033 (3)	−0.005 (2)	−0.002 (2)	0.001 (2)
C32A	0.035 (3)	0.039 (3)	0.041 (3)	−0.002 (2)	−0.007 (2)	0.007 (2)
C33A	0.040 (3)	0.045 (3)	0.041 (3)	0.000 (3)	0.004 (3)	−0.006 (3)
C34A	0.054 (3)	0.033 (3)	0.039 (3)	0.000 (3)	−0.013 (3)	−0.001 (2)
C35A	0.043 (3)	0.047 (3)	0.042 (3)	−0.009 (3)	−0.008 (3)	0.003 (3)
C36A	0.040 (3)	0.037 (3)	0.039 (3)	0.007 (2)	−0.004 (2)	0.000 (2)
N1B	0.032 (2)	0.046 (3)	0.040 (3)	−0.007 (2)	−0.004 (2)	−0.009 (2)
N2B	0.042 (2)	0.038 (2)	0.034 (3)	−0.003 (2)	−0.004 (2)	−0.001 (2)
N11B	0.033 (2)	0.048 (3)	0.029 (2)	0.004 (2)	−0.0017 (18)	0.003 (2)
N14B	0.041 (3)	0.042 (3)	0.036 (3)	0.005 (2)	−0.008 (2)	−0.001 (2)
C3B	0.033 (3)	0.047 (3)	0.032 (3)	−0.001 (2)	−0.003 (2)	0.003 (2)
C4B	0.031 (3)	0.038 (3)	0.034 (3)	0.005 (2)	−0.002 (2)	0.001 (2)
C8B	0.033 (3)	0.040 (3)	0.035 (3)	0.003 (2)	−0.005 (2)	0.004 (2)
C12B	0.037 (3)	0.033 (3)	0.037 (3)	0.004 (2)	0.000 (2)	0.004 (2)
C13B	0.033 (3)	0.044 (3)	0.035 (3)	0.002 (2)	−0.006 (2)	0.000 (2)
C15B	0.032 (3)	0.042 (3)	0.045 (3)	0.001 (2)	−0.007 (2)	0.006 (3)
C16B	0.036 (3)	0.041 (3)	0.047 (3)	−0.002 (2)	−0.013 (3)	−0.002 (3)
C17B	0.038 (3)	0.041 (3)	0.041 (3)	0.000 (2)	0.000 (2)	−0.007 (2)
C18B	0.032 (3)	0.041 (3)	0.039 (3)	0.001 (2)	−0.001 (2)	−0.001 (2)
C31B	0.039 (3)	0.037 (3)	0.031 (3)	0.003 (2)	−0.009 (2)	0.005 (2)
C32B	0.042 (3)	0.041 (3)	0.037 (3)	0.005 (2)	−0.006 (2)	−0.005 (2)
C33B	0.038 (3)	0.048 (3)	0.039 (3)	0.002 (3)	−0.008 (2)	−0.001 (3)
C34B	0.046 (3)	0.041 (3)	0.041 (3)	0.002 (3)	−0.008 (3)	−0.002 (3)
C35B	0.044 (3)	0.039 (3)	0.041 (3)	0.009 (3)	−0.003 (3)	−0.004 (2)
C36B	0.035 (3)	0.037 (3)	0.038 (3)	−0.001 (2)	−0.006 (2)	0.000 (2)

Geometric parameters (Å, º)

N1A—C12A	1.363 (6)	N1B—N2B	1.367 (6)
N1A—N2A	1.366 (6)	N1B—C12B	1.370 (6)
N1A—H1A	0.8800	N1B—H1B	0.8800
N2A—C3A	1.291 (7)	N2B—C3B	1.282 (6)
N11A—C12A	1.312 (6)	N11B—C12B	1.318 (7)
N11A—C8A	1.374 (6)	N11B—C8B	1.375 (6)
N14A—C13A	1.307 (6)	N14B—C13B	1.307 (6)
N14A—C4A	1.381 (6)	N14B—C4B	1.387 (6)
C3A—C31A	1.451 (7)	C3B—C31B	1.470 (7)
C3A—H3A	0.9500	C3B—H3B	0.9500
C4A—C15A	1.401 (7)	C4B—C15B	1.405 (7)
C4A—C8A	1.417 (7)	C4B—C8B	1.423 (7)
C8A—C18A	1.413 (7)	C8B—C18B	1.404 (7)
C12A—C13A	1.438 (7)	C12B—C13B	1.430 (7)
C13A—H13A	0.9500	C13B—H13B	0.9500
C15A—C16A	1.363 (7)	C15B—C16B	1.365 (8)
C15A—H15A	0.9500	C15B—H15B	0.9500
C16A—C17A	1.409 (8)	C16B—C17B	1.406 (7)
C16A—H16A	0.9500	C16B—H16B	0.9500
C17A—C18A	1.363 (7)	C17B—C18B	1.373 (7)
C17A—H17A	0.9500	C17B—H17B	0.9500
C18A—H18A	0.9500	C18B—H18B	0.9500
C31A—C36A	1.393 (7)	C31B—C32B	1.389 (7)
C31A—C32A	1.415 (7)	C31B—C36B	1.391 (7)
C32A—C33A	1.392 (8)	C32B—C33B	1.383 (7)
C32A—H32A	0.9500	C32B—H32B	0.9500
C33A—C34A	1.390 (7)	C33B—C34B	1.389 (8)
C33A—H33A	0.9500	C33B—H33B	0.9500
C34A—C35A	1.372 (8)	C34B—C35B	1.391 (8)
C34A—H34A	0.9500	C34B—H34B	0.9500
C35A—C36A	1.394 (8)	C35B—C36B	1.401 (7)
C35A—H35A	0.9500	C35B—H35B	0.9500
C36A—H36A	0.9500	C36B—H36B	0.9500
C12A—N1A—N2A	119.7 (4)	N2B—N1B—C12B	119.3 (4)
C12A—N1A—H1A	120.2	N2B—N1B—H1B	120.4
N2A—N1A—H1A	120.2	C12B—N1B—H1B	120.4
C3A—N2A—N1A	117.0 (4)	C3B—N2B—N1B	116.7 (4)
C12A—N11A—C8A	117.4 (4)	C12B—N11B—C8B	116.8 (4)
C13A—N14A—C4A	117.6 (4)	C13B—N14B—C4B	117.1 (4)
N2A—C3A—C31A	121.2 (5)	N2B—C3B—C31B	119.9 (5)
N2A—C3A—H3A	119.4	N2B—C3B—H3B	120.0
C31A—C3A—H3A	119.4	C31B—C3B—H3B	120.0
N14A—C4A—C15A	120.4 (5)	N14B—C4B—C15B	121.1 (5)
N14A—C4A—C8A	120.1 (5)	N14B—C4B—C8B	119.7 (5)
C15A—C4A—C8A	119.5 (5)	C15B—C4B—C8B	119.2 (5)
N11A—C8A—C18A	119.4 (4)	N11B—C8B—C18B	119.3 (5)
N11A—C8A—C4A	121.1 (5)	N11B—C8B—C4B	121.7 (5)
C18A—C8A—C4A	119.5 (5)	C18B—C8B—C4B	119.0 (5)
N11A—C12A—N1A	117.0 (5)	N11B—C12B—N1B	116.8 (5)
N11A—C12A—C13A	121.5 (5)	N11B—C12B—C13B	121.6 (5)
N1A—C12A—C13A	121.5 (5)	N1B—C12B—C13B	121.6 (5)
N14A—C13A—C12A	122.2 (5)	N14B—C13B—C12B	123.0 (5)
N14A—C13A—H13A	118.9	N14B—C13B—H13B	118.5
C12A—C13A—H13A	118.9	C12B—C13B—H13B	118.5
C16A—C15A—C4A	120.4 (5)	C16B—C15B—C4B	120.7 (5)
C16A—C15A—H15A	119.8	C16B—C15B—H15B	119.6
C4A—C15A—H15A	119.8	C4B—C15B—H15B	119.6
C15A—C16A—C17A	119.9 (5)	C15B—C16B—C17B	120.1 (5)
C15A—C16A—H16A	120.1	C15B—C16B—H16B	119.9
C17A—C16A—H16A	120.1	C17B—C16B—H16B	119.9
C18A—C17A—C16A	121.6 (5)	C18B—C17B—C16B	120.6 (5)
C18A—C17A—H17A	119.2	C18B—C17B—H17B	119.7
C16A—C17A—H17A	119.2	C16B—C17B—H17B	119.7
C17A—C18A—C8A	119.1 (5)	C17B—C18B—C8B	120.3 (5)
C17A—C18A—H18A	120.4	C17B—C18B—H18B	119.8
C8A—C18A—H18A	120.4	C8B—C18B—H18B	119.8
C36A—C31A—C32A	118.8 (5)	C32B—C31B—C36B	119.5 (5)
C36A—C31A—C3A	120.6 (5)	C32B—C31B—C3B	119.7 (5)
C32A—C31A—C3A	120.5 (5)	C36B—C31B—C3B	120.8 (5)
C33A—C32A—C31A	119.6 (5)	C33B—C32B—C31B	120.7 (5)
C33A—C32A—H32A	120.2	C33B—C32B—H32B	119.7
C31A—C32A—H32A	120.2	C31B—C32B—H32B	119.7
C34A—C33A—C32A	120.5 (5)	C32B—C33B—C34B	120.4 (5)
C34A—C33A—H33A	119.7	C32B—C33B—H33B	119.8
C32A—C33A—H33A	119.7	C34B—C33B—H33B	119.8
C35A—C34A—C33A	120.0 (5)	C33B—C34B—C35B	119.3 (5)
C35A—C34A—H34A	120.0	C33B—C34B—H34B	120.4
C33A—C34A—H34A	120.0	C35B—C34B—H34B	120.4
C34A—C35A—C36A	120.6 (5)	C34B—C35B—C36B	120.4 (5)
C34A—C35A—H35A	119.7	C34B—C35B—H35B	119.8
C36A—C35A—H35A	119.7	C36B—C35B—H35B	119.8
C31A—C36A—C35A	120.4 (5)	C31B—C36B—C35B	119.7 (5)
C31A—C36A—H36A	119.8	C31B—C36B—H36B	120.2
C35A—C36A—H36A	119.8	C35B—C36B—H36B	120.2
C12A—N1A—N2A—C3A	−179.5 (5)	C12B—N1B—N2B—C3B	−177.7 (5)
N1A—N2A—C3A—C31A	177.6 (4)	N1B—N2B—C3B—C31B	179.7 (4)
C13A—N14A—C4A—C15A	−179.6 (5)	C13B—N14B—C4B—C15B	177.6 (5)
C13A—N14A—C4A—C8A	0.8 (7)	C13B—N14B—C4B—C8B	−2.2 (7)
C12A—N11A—C8A—C18A	178.0 (5)	C12B—N11B—C8B—C18B	−177.3 (5)
C12A—N11A—C8A—C4A	−2.3 (7)	C12B—N11B—C8B—C4B	2.6 (7)
N14A—C4A—C8A—N11A	0.6 (8)	N14B—C4B—C8B—N11B	−0.1 (8)
C15A—C4A—C8A—N11A	−179.0 (5)	C15B—C4B—C8B—N11B	−179.8 (5)
N14A—C4A—C8A—C18A	−179.7 (4)	N14B—C4B—C8B—C18B	179.8 (5)
C15A—C4A—C8A—C18A	0.7 (8)	C15B—C4B—C8B—C18B	0.0 (8)
C8A—N11A—C12A—N1A	−179.2 (4)	C8B—N11B—C12B—N1B	178.5 (4)
C8A—N11A—C12A—C13A	2.7 (7)	C8B—N11B—C12B—C13B	−2.9 (7)
N2A—N1A—C12A—N11A	172.7 (4)	N2B—N1B—C12B—N11B	174.7 (4)
N2A—N1A—C12A—C13A	−9.1 (7)	N2B—N1B—C12B—C13B	−3.9 (7)
C4A—N14A—C13A—C12A	−0.5 (7)	C4B—N14B—C13B—C12B	2.0 (8)
N11A—C12A—C13A—N14A	−1.4 (8)	N11B—C12B—C13B—N14B	0.6 (8)
N1A—C12A—C13A—N14A	−179.4 (5)	N1B—C12B—C13B—N14B	179.2 (5)
N14A—C4A—C15A—C16A	178.6 (5)	N14B—C4B—C15B—C16B	179.9 (5)
C8A—C4A—C15A—C16A	−1.8 (8)	C8B—C4B—C15B—C16B	−0.4 (8)
C4A—C15A—C16A—C17A	1.5 (8)	C4B—C15B—C16B—C17B	0.0 (8)
C15A—C16A—C17A—C18A	−0.1 (9)	C15B—C16B—C17B—C18B	0.8 (9)
C16A—C17A—C18A—C8A	−0.9 (8)	C16B—C17B—C18B—C8B	−1.1 (8)
N11A—C8A—C18A—C17A	−179.6 (5)	N11B—C8B—C18B—C17B	−179.4 (5)
C4A—C8A—C18A—C17A	0.6 (8)	C4B—C8B—C18B—C17B	0.7 (8)
N2A—C3A—C31A—C36A	−179.3 (5)	N2B—C3B—C31B—C32B	−176.0 (5)
N2A—C3A—C31A—C32A	−2.9 (8)	N2B—C3B—C31B—C36B	4.8 (8)
C36A—C31A—C32A—C33A	2.1 (8)	C36B—C31B—C32B—C33B	−2.4 (8)
C3A—C31A—C32A—C33A	−174.4 (5)	C3B—C31B—C32B—C33B	178.4 (5)
C31A—C32A—C33A—C34A	−2.4 (8)	C31B—C32B—C33B—C34B	2.7 (8)
C32A—C33A—C34A—C35A	0.8 (8)	C32B—C33B—C34B—C35B	−2.0 (8)
C33A—C34A—C35A—C36A	1.1 (8)	C33B—C34B—C35B—C36B	1.1 (8)
C32A—C31A—C36A—C35A	−0.1 (8)	C32B—C31B—C36B—C35B	1.6 (8)
C3A—C31A—C36A—C35A	176.3 (5)	C3B—C31B—C36B—C35B	−179.3 (5)
C34A—C35A—C36A—C31A	−1.5 (8)	C34B—C35B—C36B—C31B	−0.9 (8)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1A—H1A···N14A^i	0.88	2.48	3.310 (7)	157
N1B—H1B···N14B^ii	0.88	2.39	3.260 (7)	168
C15A—H15A···N11A^ii	0.95	2.43	3.359 (7)	166
C15B—H15B···N11B^i	0.95	2.41	3.320 (7)	160

Symmetry codes: (i) x−1, y, z; (ii) x+1, y, z.

(2a) (E)-2-(2-(2-chlorobenzylidene)hydrazinyl)quinoxaline

Crystal data

C15H11ClN4	Z = 2
Mr = 282.73	F(000) = 292
Triclinic, P1	Dx = 1.502 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71075 Å
a = 6.6870 (7) Å	Cell parameters from 7742 reflections
b = 7.2591 (8) Å	θ = 3.1–27.5°
c = 13.8150 (16) Å	µ = 0.30 mm^−1
α = 77.957 (6)°	T = 100 K
β = 77.357 (6)°	Block, yellow
γ = 75.560 (5)°	0.35 × 0.12 × 0.06 mm
V = 625.19 (12) Å^3

Data collection

Rigaku Saturn724+ (2x2 bin mode) diffractometer	2854 independent reflections
Radiation source: Rotating Anode	2639 reflections with I > 2σ(I)
Confocal monochromator	Rint = 0.000
Detector resolution: 28.5714 pixels mm^-1	θmax = 27.5°, θmin = 3.1°
profile data from ω–scans	h = −8→8
Absorption correction: multi-scan CrystalClear-SM Expert 2.0 r11 (Rigaku, 2011)	k = −9→9
Tmin = 0.903, Tmax = 0.982	l = −17→17
2854 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.108	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.309	H-atom parameters constrained
S = 1.18	w = 1/[σ^2(Fo^2) + (0.P)^2 + 7.6397P] where P = (Fo^2 + 2Fc^2)/3
2854 reflections	(Δ/σ)max < 0.001
183 parameters	Δρmax = 0.85 e Å^−3
0 restraints	Δρmin = −1.16 e Å^−3

Special details

Experimental. Compound (2a): m.p. 483–484 K. ¹H NMR (400 MHz, DMSO-d₆): δ 11.92 (1H, s, NH), 9.14 (1H, s, H3), 8.54 (1H, s, CH), 8.17 (1H, dd, J = 7.6 and J = 2.2 Hz, H6'), 7.93 (1H, d, J = 8.1 Hz, H5), 7.70 (2H, m, H7 and H8), 7.51 (2H, m, H3' and H4'), 7.42 (2H, m, H5' and H6). ¹³C NMR (100 MHz, DMSO-d₆): δ 150.1, 140.8, 138.0, 137.6, 136.4, 132.2, 131.9, 130.5, 130.3, 129.8, 128.8, 127.5, 126.6, 126.3, 125.4. MS/ESI (M + H): 283.0. IR (cm^–1, KBr): 1578 (C═N).

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl32	−0.3849 (2)	0.8074 (2)	0.09060 (12)	0.0168 (4)
N1	0.1252 (9)	0.4814 (8)	0.3242 (4)	0.0163 (12)
H1	−0.0052	0.4805	0.3541	0.020*
N2	0.1681 (9)	0.5527 (8)	0.2247 (4)	0.0146 (11)
N11	0.2373 (8)	0.3177 (8)	0.4698 (4)	0.0136 (11)
N14	0.6510 (8)	0.3683 (8)	0.3860 (4)	0.0131 (11)
C3	0.0079 (10)	0.6141 (9)	0.1798 (5)	0.0149 (13)
H3	−0.1295	0.6144	0.2172	0.018*
C12	0.2864 (10)	0.4103 (9)	0.3784 (5)	0.0116 (12)
C13	0.4959 (10)	0.4392 (9)	0.3361 (5)	0.0146 (12)
H13	0.5218	0.5114	0.2706	0.018*
C14A	0.6057 (10)	0.2630 (9)	0.4809 (5)	0.0125 (12)
C15	0.7671 (10)	0.1826 (9)	0.5369 (5)	0.0156 (13)
H15	0.9059	0.1994	0.5098	0.019*
C16	0.7223 (11)	0.0792 (10)	0.6312 (5)	0.0180 (13)
H16	0.8316	0.0238	0.6690	0.022*
C17	0.5176 (11)	0.0536 (10)	0.6729 (5)	0.0177 (13)
H17	0.4902	−0.0194	0.7381	0.021*
C18	0.3564 (10)	0.1342 (9)	0.6194 (5)	0.0143 (12)
H18	0.2181	0.1173	0.6478	0.017*
C18A	0.3977 (10)	0.2420 (9)	0.5222 (4)	0.0113 (12)
C31	0.0380 (10)	0.6834 (9)	0.0713 (5)	0.0138 (12)
C32	−0.1320 (10)	0.7724 (9)	0.0224 (5)	0.0134 (12)
C33	−0.1034 (10)	0.8334 (9)	−0.0814 (5)	0.0162 (13)
H33	−0.2208	0.8948	−0.1132	0.019*
C34	0.0960 (11)	0.8043 (10)	−0.1377 (5)	0.0192 (14)
H34	0.1162	0.8442	−0.2085	0.023*
C35	0.2667 (10)	0.7169 (10)	−0.0909 (5)	0.0169 (13)
H35	0.4041	0.6985	−0.1297	0.020*
C36	0.2387 (11)	0.6561 (10)	0.0122 (5)	0.0160 (13)
H36	0.3573	0.5950	0.0432	0.019*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl32	0.0113 (7)	0.0198 (8)	0.0167 (7)	0.0002 (5)	−0.0027 (5)	−0.0014 (6)
N1	0.013 (3)	0.023 (3)	0.012 (3)	−0.006 (2)	−0.003 (2)	0.002 (2)
N2	0.016 (3)	0.017 (3)	0.010 (2)	−0.003 (2)	−0.002 (2)	−0.001 (2)
N11	0.014 (3)	0.014 (3)	0.013 (2)	−0.004 (2)	−0.001 (2)	−0.003 (2)
N14	0.013 (2)	0.015 (3)	0.012 (2)	−0.005 (2)	0.000 (2)	−0.004 (2)
C3	0.014 (3)	0.018 (3)	0.012 (3)	−0.002 (2)	−0.001 (2)	−0.006 (2)
C12	0.012 (3)	0.013 (3)	0.010 (3)	−0.001 (2)	−0.002 (2)	−0.005 (2)
C13	0.018 (3)	0.015 (3)	0.012 (3)	−0.005 (2)	−0.001 (2)	−0.004 (2)
C14A	0.013 (3)	0.011 (3)	0.013 (3)	−0.001 (2)	−0.003 (2)	−0.003 (2)
C15	0.014 (3)	0.014 (3)	0.020 (3)	−0.005 (2)	−0.002 (2)	−0.003 (2)
C16	0.018 (3)	0.021 (3)	0.018 (3)	−0.006 (3)	−0.006 (3)	−0.004 (3)
C17	0.025 (3)	0.017 (3)	0.012 (3)	−0.005 (3)	−0.007 (3)	0.000 (2)
C18	0.015 (3)	0.017 (3)	0.012 (3)	−0.005 (2)	0.000 (2)	−0.004 (2)
C18A	0.013 (3)	0.009 (3)	0.010 (3)	0.000 (2)	−0.001 (2)	−0.003 (2)
C31	0.015 (3)	0.017 (3)	0.011 (3)	−0.008 (2)	0.000 (2)	−0.004 (2)
C32	0.015 (3)	0.011 (3)	0.015 (3)	−0.003 (2)	−0.001 (2)	−0.003 (2)
C33	0.015 (3)	0.014 (3)	0.018 (3)	0.000 (2)	−0.006 (3)	−0.001 (2)
C34	0.025 (3)	0.016 (3)	0.013 (3)	−0.006 (3)	0.001 (3)	0.001 (2)
C35	0.014 (3)	0.018 (3)	0.017 (3)	−0.004 (2)	0.000 (2)	−0.002 (3)
C36	0.017 (3)	0.018 (3)	0.013 (3)	−0.005 (3)	−0.002 (2)	−0.001 (2)

Geometric parameters (Å, º)

Cl32—C32	1.732 (6)	C16—C17	1.406 (10)
N1—N2	1.358 (7)	C16—H16	0.9500
N1—C12	1.379 (8)	C17—C18	1.380 (9)
N1—H1	0.8800	C17—H17	0.9500
N2—C3	1.292 (8)	C18—C18A	1.414 (8)
N11—C12	1.315 (8)	C18—H18	0.9500
N11—C18A	1.362 (8)	C31—C32	1.398 (9)
N14—C13	1.309 (8)	C31—C36	1.401 (9)
N14—C14A	1.386 (8)	C32—C33	1.395 (9)
C3—C31	1.465 (9)	C33—C34	1.379 (9)
C3—H3	0.9500	C33—H33	0.9500
C12—C13	1.444 (9)	C34—C35	1.384 (10)
C13—H13	0.9500	C34—H34	0.9500
C14A—C15	1.402 (9)	C35—C36	1.385 (9)
C14A—C18A	1.416 (9)	C35—H35	0.9500
C15—C16	1.372 (9)	C36—H36	0.9500
C15—H15	0.9500
N2—N1—C12	119.9 (5)	C16—C17—H17	119.9
N2—N1—H1	120.1	C17—C18—C18A	119.8 (6)
C12—N1—H1	120.1	C17—C18—H18	120.1
C3—N2—N1	115.6 (6)	C18A—C18—H18	120.1
C12—N11—C18A	116.4 (5)	N11—C18A—C18	119.0 (6)
C13—N14—C14A	117.1 (5)	N11—C18A—C14A	121.9 (6)
N2—C3—C31	120.0 (6)	C18—C18A—C14A	119.0 (6)
N2—C3—H3	120.0	C32—C31—C36	117.6 (6)
C31—C3—H3	120.0	C32—C31—C3	121.5 (6)
N11—C12—N1	116.3 (6)	C36—C31—C3	120.9 (6)
N11—C12—C13	122.6 (6)	C33—C32—C31	121.4 (6)
N1—C12—C13	121.1 (6)	C33—C32—Cl32	118.5 (5)
N14—C13—C12	121.5 (6)	C31—C32—Cl32	120.1 (5)
N14—C13—H13	119.2	C34—C33—C32	119.7 (6)
C12—C13—H13	119.2	C34—C33—H33	120.2
N14—C14A—C15	119.2 (6)	C32—C33—H33	120.2
N14—C14A—C18A	120.4 (6)	C33—C34—C35	119.9 (6)
C15—C14A—C18A	120.4 (6)	C33—C34—H34	120.0
C16—C15—C14A	119.3 (6)	C35—C34—H34	120.0
C16—C15—H15	120.4	C34—C35—C36	120.5 (6)
C14A—C15—H15	120.4	C34—C35—H35	119.8
C15—C16—C17	121.3 (6)	C36—C35—H35	119.8
C15—C16—H16	119.4	C35—C36—C31	120.9 (6)
C17—C16—H16	119.4	C35—C36—H36	119.5
C18—C17—C16	120.2 (6)	C31—C36—H36	119.5
C18—C17—H17	119.9
C12—N1—N2—C3	179.2 (6)	C17—C18—C18A—C14A	0.9 (9)
N1—N2—C3—C31	−176.4 (6)	N14—C14A—C18A—N11	2.3 (9)
C18A—N11—C12—N1	178.0 (5)	C15—C14A—C18A—N11	−179.7 (6)
C18A—N11—C12—C13	−2.7 (9)	N14—C14A—C18A—C18	−179.8 (5)
N2—N1—C12—N11	−170.1 (6)	C15—C14A—C18A—C18	−1.8 (9)
N2—N1—C12—C13	10.6 (9)	N2—C3—C31—C32	−172.1 (6)
C14A—N14—C13—C12	0.4 (9)	N2—C3—C31—C36	10.3 (10)
N11—C12—C13—N14	2.4 (10)	C36—C31—C32—C33	−0.5 (9)
N1—C12—C13—N14	−178.3 (6)	C3—C31—C32—C33	−178.2 (6)
C13—N14—C14A—C15	179.4 (6)	C36—C31—C32—Cl32	179.0 (5)
C13—N14—C14A—C18A	−2.6 (9)	C3—C31—C32—Cl32	1.3 (8)
N14—C14A—C15—C16	179.6 (6)	C31—C32—C33—C34	0.6 (10)
C18A—C14A—C15—C16	1.6 (9)	Cl32—C32—C33—C34	−178.9 (5)
C14A—C15—C16—C17	−0.4 (10)	C32—C33—C34—C35	−0.7 (10)
C15—C16—C17—C18	−0.5 (10)	C33—C34—C35—C36	0.8 (10)
C16—C17—C18—C18A	0.3 (10)	C34—C35—C36—C31	−0.7 (10)
C12—N11—C18A—C18	−177.5 (6)	C32—C31—C36—C35	0.5 (9)
C12—N11—C18A—C14A	0.4 (9)	C3—C31—C36—C35	178.2 (6)
C17—C18—C18A—N11	178.8 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N14^i	0.88	2.55	3.359 (8)	154
C15—H15···N11^ii	0.95	2.48	3.405 (9)	163

Symmetry codes: (i) x−1, y, z; (ii) x+1, y, z.

(2b) (E)-2-(2-(3-chlorobenzylidene)hydrazinyl)quinoxaline

Crystal data

C15H11ClN4	F(000) = 1168
Mr = 282.73	Dx = 1.438 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71075 Å
Hall symbol: -C 2yc	Cell parameters from 799 reflections
a = 32.14 (5) Å	θ = 3.0–28.8°
b = 6.882 (9) Å	µ = 0.29 mm^−1
c = 12.450 (18) Å	T = 100 K
β = 108.43 (3)°	Plate, yellow
V = 2613 (7) Å^3	0.24 × 0.10 × 0.01 mm
Z = 8

Data collection

Rigaku Saturn724+ (2x2 bin mode) diffractometer	2262 independent reflections
Radiation source: Rotating Anode	2174 reflections with I > 2σ(I)
Confocal monochromator	Rint = 0.031
Detector resolution: 28.5714 pixels mm^-1	θmax = 25.0°, θmin = 3.0°
profile data from ω–scans	h = −38→37
Absorption correction: multi-scan CrystalClear-SM Expert 3.1 b13a (Rigaku, 20112)	k = −7→8
Tmin = 0.934, Tmax = 0.997	l = −14→14
9205 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.066	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.136	H-atom parameters constrained
S = 1.15	w = 1/[σ^2(Fo^2) + (0.0185P)^2 + 18.0773P] where P = (Fo^2 + 2Fc^2)/3
2262 reflections	(Δ/σ)max < 0.001
181 parameters	Δρmax = 0.59 e Å^−3
0 restraints	Δρmin = −0.49 e Å^−3

Special details

Experimental. Compound (2b): m.p. 508–509 K. ¹H NMR (400 MHz, DMSO-d₆): δ 11.79 (1H, s, NH), 9.12 (1H, s, H3), 8.11 (1H, s, CH), 7.91 (1H, d, J = 8.2 Hz, H5), 7.83 (1H, s, H2'), 7.68 (3H, m, H7, H8 and H4' or H6'), 7.50 (1H, dt, J = 8.2 and J = 1.7 Hz, H6), 7.46 (1H, t, J = 7.8 Hz, H5'), 7.41 (1H, m, H4' or H6'). ¹³C NMR (100 MHz, DMSO-d₆): δ 150.2, 140.8, 140.2, 138.0, 137.0, 136.5, 133.7, 130.6, 130.3, 128.8, 127.1, 126.2, 125.7, 125.3, 125.2. MS/ESI (M + H): 283.0. IR (cm^–1, KBr): 1587 (C═N).

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl33	0.03042 (3)	0.20933 (17)	0.66335 (7)	0.0368 (3)
N1	0.23759 (8)	0.4665 (4)	0.5607 (2)	0.0161 (6)
H1	0.2485	0.4595	0.6349	0.019*
N11	0.30505 (8)	0.5637 (4)	0.5551 (2)	0.0142 (6)
N2	0.19429 (8)	0.4264 (4)	0.5085 (2)	0.0146 (6)
C12	0.26406 (9)	0.5177 (5)	0.4980 (3)	0.0147 (6)
C3	0.17201 (10)	0.3776 (5)	0.5737 (2)	0.0143 (6)
H3	0.1865	0.3665	0.6528	0.017*
N14	0.27291 (8)	0.5654 (4)	0.3155 (2)	0.0146 (6)
C14A	0.31623 (10)	0.6109 (5)	0.3724 (2)	0.0140 (6)
C32	0.10263 (10)	0.2937 (5)	0.6053 (3)	0.0171 (7)
H32	0.1181	0.2838	0.6840	0.021*
C18	0.37652 (10)	0.6493 (5)	0.5481 (3)	0.0173 (7)
H18	0.3875	0.6470	0.6285	0.021*
C18A	0.33189 (10)	0.6077 (4)	0.4925 (2)	0.0137 (6)
C13	0.24789 (10)	0.5196 (5)	0.3769 (2)	0.0147 (6)
H13	0.2181	0.4866	0.3398	0.018*
C15	0.34488 (10)	0.6585 (5)	0.3106 (3)	0.0160 (7)
H15	0.3343	0.6630	0.2303	0.019*
C16	0.38837 (10)	0.6983 (5)	0.3679 (3)	0.0190 (7)
H16	0.4078	0.7296	0.3267	0.023*
C31	0.12497 (10)	0.3387 (5)	0.5289 (3)	0.0153 (7)
C33	0.05754 (10)	0.2636 (5)	0.5656 (3)	0.0194 (7)
C17	0.40413 (10)	0.6931 (5)	0.4871 (3)	0.0186 (7)
H17	0.4342	0.7200	0.5255	0.022*
C34	0.03397 (10)	0.2753 (6)	0.4519 (3)	0.0245 (8)
H34	0.0032	0.2532	0.4259	0.029*
C36	0.10152 (10)	0.3531 (5)	0.4135 (3)	0.0197 (7)
H36	0.1163	0.3849	0.3608	0.024*
C35	0.05673 (11)	0.3209 (6)	0.3762 (3)	0.0262 (8)
H35	0.0411	0.3298	0.2976	0.031*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl33	0.0172 (4)	0.0709 (8)	0.0248 (4)	−0.0063 (4)	0.0103 (3)	0.0061 (5)
N1	0.0147 (12)	0.0219 (16)	0.0116 (12)	−0.0031 (11)	0.0039 (10)	−0.0012 (11)
N11	0.0166 (13)	0.0120 (14)	0.0140 (12)	−0.0006 (11)	0.0047 (10)	−0.0003 (10)
N2	0.0134 (12)	0.0124 (14)	0.0168 (13)	0.0008 (11)	0.0031 (10)	−0.0023 (11)
C12	0.0165 (15)	0.0102 (16)	0.0179 (15)	0.0011 (12)	0.0064 (12)	0.0005 (12)
C3	0.0185 (15)	0.0108 (16)	0.0132 (14)	0.0018 (12)	0.0046 (12)	0.0003 (12)
N14	0.0176 (13)	0.0122 (14)	0.0136 (12)	0.0002 (11)	0.0044 (10)	−0.0005 (11)
C14A	0.0160 (14)	0.0097 (16)	0.0156 (15)	0.0027 (12)	0.0039 (12)	0.0006 (12)
C32	0.0166 (15)	0.0175 (18)	0.0160 (15)	0.0019 (13)	0.0035 (12)	−0.0014 (13)
C18	0.0185 (15)	0.0170 (18)	0.0150 (15)	−0.0003 (13)	0.0033 (12)	0.0001 (13)
C18A	0.0173 (15)	0.0073 (15)	0.0167 (15)	0.0012 (12)	0.0055 (12)	0.0001 (12)
C13	0.0147 (14)	0.0112 (16)	0.0177 (15)	−0.0014 (12)	0.0044 (12)	−0.0020 (13)
C15	0.0190 (15)	0.0132 (17)	0.0165 (15)	0.0016 (13)	0.0064 (12)	0.0002 (13)
C16	0.0173 (15)	0.0200 (19)	0.0219 (16)	−0.0014 (13)	0.0093 (13)	−0.0001 (14)
C31	0.0159 (15)	0.0101 (16)	0.0204 (16)	0.0005 (12)	0.0065 (12)	−0.0020 (13)
C33	0.0166 (15)	0.0230 (19)	0.0209 (16)	−0.0002 (14)	0.0090 (13)	−0.0003 (14)
C17	0.0156 (15)	0.0177 (18)	0.0216 (16)	−0.0012 (13)	0.0047 (12)	−0.0012 (13)
C34	0.0122 (15)	0.036 (2)	0.0245 (17)	−0.0003 (15)	0.0044 (13)	−0.0016 (16)
C36	0.0222 (16)	0.0197 (19)	0.0186 (16)	0.0031 (14)	0.0084 (13)	0.0000 (14)
C35	0.0187 (16)	0.039 (2)	0.0181 (16)	0.0007 (15)	0.0016 (13)	−0.0017 (15)

Geometric parameters (Å, º)

Cl33—C33	1.747 (4)	C18—C17	1.372 (5)
N1—N2	1.365 (4)	C18—C18A	1.411 (5)
N1—C12	1.370 (4)	C18—H18	0.9500
N1—H1	0.8800	C13—H13	0.9500
N11—C12	1.323 (4)	C15—C16	1.381 (5)
N11—C18A	1.368 (4)	C15—H15	0.9500
N2—C3	1.285 (4)	C16—C17	1.408 (5)
C12—C13	1.432 (5)	C16—H16	0.9500
C3—C31	1.461 (5)	C31—C36	1.399 (5)
C3—H3	0.9500	C33—C34	1.380 (5)
N14—C13	1.310 (4)	C17—H17	0.9500
N14—C14A	1.384 (4)	C34—C35	1.400 (5)
C14A—C15	1.412 (5)	C34—H34	0.9500
C14A—C18A	1.418 (5)	C36—C35	1.384 (5)
C32—C33	1.391 (5)	C36—H36	0.9500
C32—C31	1.396 (5)	C35—H35	0.9500
C32—H32	0.9500
N2—N1—C12	120.3 (3)	C12—C13—H13	119.0
N2—N1—H1	119.9	C16—C15—C14A	119.5 (3)
C12—N1—H1	119.9	C16—C15—H15	120.3
C12—N11—C18A	116.6 (3)	C14A—C15—H15	120.3
C3—N2—N1	116.1 (3)	C15—C16—C17	120.5 (3)
N11—C12—N1	116.6 (3)	C15—C16—H16	119.8
N11—C12—C13	122.2 (3)	C17—C16—H16	119.8
N1—C12—C13	121.2 (3)	C32—C31—C36	119.3 (3)
N2—C3—C31	121.5 (3)	C32—C31—C3	118.3 (3)
N2—C3—H3	119.2	C36—C31—C3	122.4 (3)
C31—C3—H3	119.2	C34—C33—C32	121.9 (3)
C13—N14—C14A	117.4 (3)	C34—C33—Cl33	119.6 (3)
N14—C14A—C15	119.8 (3)	C32—C33—Cl33	118.5 (3)
N14—C14A—C18A	120.0 (3)	C18—C17—C16	120.6 (3)
C15—C14A—C18A	120.2 (3)	C18—C17—H17	119.7
C33—C32—C31	119.5 (3)	C16—C17—H17	119.7
C33—C32—H32	120.2	C33—C34—C35	118.0 (3)
C31—C32—H32	120.2	C33—C34—H34	121.0
C17—C18—C18A	120.5 (3)	C35—C34—H34	121.0
C17—C18—H18	119.8	C35—C36—C31	119.9 (3)
C18A—C18—H18	119.8	C35—C36—H36	120.0
N11—C18A—C18	119.4 (3)	C31—C36—H36	120.0
N11—C18A—C14A	121.8 (3)	C36—C35—C34	121.3 (3)
C18—C18A—C14A	118.8 (3)	C36—C35—H35	119.3
N14—C13—C12	122.1 (3)	C34—C35—H35	119.3
N14—C13—H13	119.0
C12—N1—N2—C3	179.3 (3)	N1—C12—C13—N14	−179.0 (3)
C18A—N11—C12—N1	177.6 (3)	N14—C14A—C15—C16	−178.2 (3)
C18A—N11—C12—C13	−2.0 (5)	C18A—C14A—C15—C16	1.1 (5)
N2—N1—C12—N11	176.7 (3)	C14A—C15—C16—C17	−0.4 (5)
N2—N1—C12—C13	−3.7 (5)	C33—C32—C31—C36	0.1 (5)
N1—N2—C3—C31	177.5 (3)	C33—C32—C31—C3	177.5 (3)
C13—N14—C14A—C15	179.0 (3)	N2—C3—C31—C32	−177.5 (3)
C13—N14—C14A—C18A	−0.3 (4)	N2—C3—C31—C36	−0.3 (5)
C12—N11—C18A—C18	−177.1 (3)	C31—C32—C33—C34	0.5 (5)
C12—N11—C18A—C14A	2.3 (4)	C31—C32—C33—Cl33	−179.5 (3)
C17—C18—C18A—N11	179.8 (3)	C18A—C18—C17—C16	0.4 (5)
C17—C18—C18A—C14A	0.3 (5)	C15—C16—C17—C18	−0.4 (5)
N14—C14A—C18A—N11	−1.2 (5)	C32—C33—C34—C35	−0.6 (6)
C15—C14A—C18A—N11	179.5 (3)	Cl33—C33—C34—C35	179.4 (3)
N14—C14A—C18A—C18	178.2 (3)	C32—C31—C36—C35	−0.6 (5)
C15—C14A—C18A—C18	−1.1 (5)	C3—C31—C36—C35	−177.9 (3)
C14A—N14—C13—C12	0.6 (5)	C31—C36—C35—C34	0.5 (6)
N11—C12—C13—N14	0.6 (5)	C33—C34—C35—C36	0.1 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N14^i	0.88	2.14	3.021 (6)	178
C15—H15···N11^ii	0.95	2.60	3.394 (6)	141

Symmetry codes: (i) x, −y+1, z+1/2; (ii) x, −y+1, z−1/2.

(2c) (E)-2-(2-(4-chlorobenzylidene)hydrazinyl)quinoxaline

Crystal data

C15H11ClN4	F(000) = 584
Mr = 282.73	Dx = 1.409 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71075 Å
Hall symbol: -P 2ybc	Cell parameters from 14589 reflections
a = 11.6658 (6) Å	θ = 3.5–27.5°
b = 10.0515 (5) Å	µ = 0.28 mm^−1
c = 11.7575 (8) Å	T = 100 K
β = 104.818 (7)°	Prism, yellow
V = 1332.82 (13) Å^3	0.16 × 0.10 × 0.05 mm
Z = 4

Data collection

Rigaku Saturn724+ (2x2 bin mode) diffractometer	3031 independent reflections
Radiation source: Rotating Anode	2649 reflections with I > 2σ(I)
Confocal monochromator	Rint = 0.032
Detector resolution: 28.5714 pixels mm^-1	θmax = 27.5°, θmin = 3.5°
profile data from ω–scans	h = −15→15
Absorption correction: multi-scan CrystalClear-SM Expert 2.0 r11 (Rigaku, 2011)	k = −13→13
Tmin = 0.956, Tmax = 0.986	l = −15→10
16763 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.086	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0404P)^2 + 0.4311P] where P = (Fo^2 + 2Fc^2)/3
3031 reflections	(Δ/σ)max = 0.001
181 parameters	Δρmax = 0.32 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

Special details

Experimental. Compound (2c): m.p. 435–436 K. ¹H NMR (400 MHz, DMSO-d₆): δ 11.76 (1H, s, NH), 9.11 (1H, s, H3), 8.13 (1H, s, CH), 7.92 (1H, d, J = 8.2 Hz, H5), 7.80 (2H, d, J = 8.5 Hz, H2' and H6'), 7.70 (1H, d, J = 8.2 Hz, H8), 7.67 (1H, t, J = 8.2 Hz, H7), 7.50 (1H, m, H6), 7.48 (2H, d, J = 8.5 Hz, H3' and H5'). ¹³C NMR (100 MHz, DMSO-d₆): δ 150.2, 140.8, 140.4, 138.0, 136.4, 133.6, 133.5, 130.3, 128.8, 128.7, 128.1, 126.2, 125.2. MS/ESI (M – H): 281.1. IR (cm^–1, KBr): 3190 (N—H); 1578 (C═N).

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl34	1.04280 (3)	0.12798 (3)	0.62474 (3)	0.03283 (12)
N1	0.52829 (8)	0.66802 (10)	0.60545 (9)	0.0191 (2)
H1	0.5015	0.6589	0.6685	0.023*
N2	0.61932 (8)	0.59043 (10)	0.59043 (9)	0.0182 (2)
C3	0.66234 (10)	0.50625 (12)	0.67225 (10)	0.0186 (2)
H3	0.6306	0.5003	0.7388	0.022*
N14	0.47011 (8)	0.84947 (10)	0.33081 (9)	0.0191 (2)
C13	0.51663 (10)	0.76576 (11)	0.41418 (10)	0.0180 (2)
H13	0.5769	0.7069	0.4038	0.022*
C12	0.47938 (10)	0.75975 (11)	0.52172 (10)	0.0162 (2)
N11	0.39740 (8)	0.83969 (10)	0.54260 (8)	0.0176 (2)
C15	0.33043 (11)	1.02480 (13)	0.26018 (11)	0.0247 (3)
H15	0.3540	1.0271	0.1886	0.030*
C31	0.76041 (10)	0.41929 (12)	0.66313 (10)	0.0184 (2)
C18	0.25982 (10)	1.01790 (12)	0.47019 (11)	0.0230 (3)
H18	0.2349	1.0166	0.5410	0.028*
C17	0.20931 (11)	1.10625 (13)	0.38278 (13)	0.0286 (3)
H17	0.1498	1.1658	0.3938	0.034*
C16	0.24459 (12)	1.10983 (13)	0.27679 (13)	0.0291 (3)
H16	0.2087	1.1713	0.2169	0.035*
C32	0.79524 (10)	0.31593 (12)	0.74354 (10)	0.0198 (2)
H32	0.7580	0.3057	0.8060	0.024*
C33	0.88381 (10)	0.22753 (12)	0.73351 (11)	0.0225 (3)
H33	0.9069	0.1569	0.7883	0.027*
C34	0.93776 (10)	0.24397 (12)	0.64266 (11)	0.0228 (3)
C35	0.90808 (11)	0.34895 (14)	0.56408 (12)	0.0266 (3)
H35	0.9482	0.3609	0.5039	0.032*
C36	0.81962 (11)	0.43581 (13)	0.57427 (11)	0.0243 (3)
H36	0.7986	0.5076	0.5204	0.029*
C18A	0.34862 (10)	0.92891 (11)	0.45550 (10)	0.0180 (2)
C14A	0.38393 (10)	0.93395 (12)	0.34907 (10)	0.0185 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl34	0.02087 (16)	0.02935 (18)	0.0481 (2)	0.00511 (12)	0.00851 (14)	−0.01244 (14)
N1	0.0211 (5)	0.0224 (5)	0.0163 (5)	0.0047 (4)	0.0096 (4)	0.0006 (4)
N2	0.0172 (4)	0.0192 (5)	0.0190 (5)	0.0013 (4)	0.0061 (4)	−0.0025 (4)
C3	0.0193 (5)	0.0203 (6)	0.0171 (6)	−0.0008 (4)	0.0061 (4)	−0.0025 (4)
N14	0.0192 (5)	0.0214 (5)	0.0176 (5)	−0.0028 (4)	0.0065 (4)	−0.0007 (4)
C13	0.0189 (5)	0.0195 (5)	0.0174 (6)	0.0000 (4)	0.0077 (4)	−0.0023 (4)
C12	0.0159 (5)	0.0182 (5)	0.0147 (5)	−0.0019 (4)	0.0045 (4)	−0.0023 (4)
N11	0.0170 (4)	0.0193 (5)	0.0169 (5)	−0.0003 (4)	0.0050 (4)	−0.0027 (4)
C15	0.0252 (6)	0.0251 (6)	0.0227 (6)	−0.0042 (5)	0.0039 (5)	0.0040 (5)
C31	0.0170 (5)	0.0205 (6)	0.0170 (6)	−0.0002 (4)	0.0031 (4)	−0.0033 (4)
C18	0.0199 (6)	0.0245 (6)	0.0244 (6)	0.0010 (5)	0.0052 (5)	−0.0047 (5)
C17	0.0221 (6)	0.0242 (6)	0.0367 (8)	0.0045 (5)	0.0022 (5)	−0.0026 (6)
C16	0.0264 (6)	0.0240 (6)	0.0326 (7)	0.0011 (5)	−0.0003 (5)	0.0076 (5)
C32	0.0207 (5)	0.0200 (6)	0.0189 (6)	−0.0017 (4)	0.0054 (5)	−0.0014 (5)
C33	0.0215 (6)	0.0190 (6)	0.0246 (6)	−0.0001 (4)	0.0016 (5)	−0.0007 (5)
C34	0.0155 (5)	0.0232 (6)	0.0279 (7)	0.0018 (4)	0.0024 (5)	−0.0092 (5)
C35	0.0229 (6)	0.0367 (7)	0.0221 (6)	0.0029 (5)	0.0091 (5)	−0.0024 (5)
C36	0.0238 (6)	0.0299 (7)	0.0200 (6)	0.0041 (5)	0.0072 (5)	0.0037 (5)
C18A	0.0162 (5)	0.0186 (5)	0.0183 (6)	−0.0024 (4)	0.0031 (4)	−0.0034 (4)
C14A	0.0170 (5)	0.0186 (5)	0.0193 (6)	−0.0042 (4)	0.0037 (4)	−0.0016 (4)

Geometric parameters (Å, º)

Cl34—C34	1.7427 (12)	C31—C36	1.4020 (17)
N1—C12	1.3630 (15)	C18—C17	1.3720 (18)
N1—N2	1.3649 (13)	C18—C18A	1.4123 (16)
N1—H1	0.8800	C18—H18	0.9500
N2—C3	1.2831 (15)	C17—C16	1.409 (2)
C3—C31	1.4653 (16)	C17—H17	0.9500
C3—H3	0.9500	C16—H16	0.9500
N14—C13	1.3005 (15)	C32—C33	1.3904 (16)
N14—C14A	1.3741 (15)	C32—H32	0.9500
C13—C12	1.4394 (16)	C33—C34	1.3814 (18)
C13—H13	0.9500	C33—H33	0.9500
C12—N11	1.3193 (14)	C34—C35	1.3869 (19)
N11—C18A	1.3706 (15)	C35—C36	1.3801 (17)
C15—C16	1.3680 (19)	C35—H35	0.9500
C15—C14A	1.4078 (17)	C36—H36	0.9500
C15—H15	0.9500	C18A—C14A	1.4149 (17)
C31—C32	1.3935 (16)
C12—N1—N2	119.26 (9)	C16—C17—H17	119.6
C12—N1—H1	120.4	C15—C16—C17	120.02 (12)
N2—N1—H1	120.4	C15—C16—H16	120.0
C3—N2—N1	116.61 (10)	C17—C16—H16	120.0
N2—C3—C31	120.10 (11)	C33—C32—C31	120.86 (11)
N2—C3—H3	119.9	C33—C32—H32	119.6
C31—C3—H3	119.9	C31—C32—H32	119.6
C13—N14—C14A	117.59 (10)	C34—C33—C32	118.99 (11)
N14—C13—C12	121.84 (10)	C34—C33—H33	120.5
N14—C13—H13	119.1	C32—C33—H33	120.5
C12—C13—H13	119.1	C33—C34—C35	121.37 (11)
N11—C12—N1	117.84 (10)	C33—C34—Cl34	119.14 (10)
N11—C12—C13	122.27 (10)	C35—C34—Cl34	119.47 (10)
N1—C12—C13	119.88 (10)	C36—C35—C34	119.23 (12)
C12—N11—C18A	116.21 (10)	C36—C35—H35	120.4
C16—C15—C14A	120.07 (12)	C34—C35—H35	120.4
C16—C15—H15	120.0	C35—C36—C31	120.77 (12)
C14A—C15—H15	120.0	C35—C36—H36	119.6
C32—C31—C36	118.70 (11)	C31—C36—H36	119.6
C32—C31—C3	119.52 (11)	N11—C18A—C18	120.03 (11)
C36—C31—C3	121.77 (11)	N11—C18A—C14A	121.67 (10)
C17—C18—C18A	120.42 (12)	C18—C18A—C14A	118.30 (11)
C17—C18—H18	119.8	N14—C14A—C15	119.22 (11)
C18A—C18—H18	119.8	N14—C14A—C18A	120.41 (10)
C18—C17—C16	120.82 (12)	C15—C14A—C18A	120.38 (11)
C18—C17—H17	119.6
C12—N1—N2—C3	179.67 (10)	C32—C33—C34—Cl34	−176.38 (9)
N1—N2—C3—C31	−179.87 (10)	C33—C34—C35—C36	−2.50 (19)
C14A—N14—C13—C12	0.57 (16)	Cl34—C34—C35—C36	176.01 (10)
N2—N1—C12—N11	−175.25 (10)	C34—C35—C36—C31	0.34 (19)
N2—N1—C12—C13	5.52 (16)	C32—C31—C36—C35	2.08 (18)
N14—C13—C12—N11	−0.95 (17)	C3—C31—C36—C35	−176.97 (11)
N14—C13—C12—N1	178.23 (11)	C12—N11—C18A—C18	179.71 (10)
N1—C12—N11—C18A	−178.79 (10)	C12—N11—C18A—C14A	0.42 (16)
C13—C12—N11—C18A	0.41 (16)	C17—C18—C18A—N11	−179.07 (11)
N2—C3—C31—C32	−170.96 (11)	C17—C18—C18A—C14A	0.25 (17)
N2—C3—C31—C36	8.08 (18)	C13—N14—C14A—C15	−179.19 (11)
C18A—C18—C17—C16	0.17 (19)	C13—N14—C14A—C18A	0.25 (16)
C14A—C15—C16—C17	−0.22 (19)	C16—C15—C14A—N14	−179.91 (11)
C18—C17—C16—C15	−0.2 (2)	C16—C15—C14A—C18A	0.65 (18)
C36—C31—C32—C33	−2.45 (17)	N11—C18A—C14A—N14	−0.78 (17)
C3—C31—C32—C33	176.62 (10)	C18—C18A—C14A—N14	179.91 (10)
C31—C32—C33—C34	0.39 (17)	N11—C18A—C14A—C15	178.65 (11)
C32—C33—C34—C35	2.13 (18)	C18—C18A—C14A—C15	−0.66 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N14^i	0.88	2.03	2.9038 (14)	169
C16—H16···Cl34^ii	0.95	2.81	3.6783 (13)	152

Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) x−1, −y+3/2, z−1/2.

(3a) (E)-2-(2-(2-bromobenzylidene)hydrazinyl)quinoxaline

Crystal data

C15H11BrN4	F(000) = 1312
Mr = 327.19	Dx = 1.635 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71075 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 6233 reflections
a = 6.9712 (10) Å	θ = 2.6–30.1°
b = 12.6370 (17) Å	µ = 3.09 mm^−1
c = 30.182 (4) Å	T = 100 K
V = 2658.9 (6) Å^3	Block, orange
Z = 8	0.16 × 0.16 × 0.14 mm

Data collection

Rigaku Saturn724+ (2x2 bin mode) diffractometer	3685 independent reflections
Radiation source: Sealed Tube	3324 reflections with I > 2σ(I)
Graphite Monochromator monochromator	Rint = 0.037
Detector resolution: 28.5714 pixels mm^-1	θmax = 30.2°, θmin = 2.7°
profile data from ω–scans	h = −9→9
Absorption correction: multi-scan CrystalClear-SM Expert 3.1 b18 (Rigaku, 20112)	k = −13→17
Tmin = 0.638, Tmax = 0.672	l = −41→42
19111 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.088	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0343P)^2 + 3.5415P] where P = (Fo^2 + 2Fc^2)/3
3685 reflections	(Δ/σ)max = 0.001
181 parameters	Δρmax = 0.78 e Å^−3
0 restraints	Δρmin = −0.65 e Å^−3

Special details

Experimental. Compound (3a): m.p. 492–493 K. ¹H NMR (400 MHz, DMSO-d₆): δ 11.94 (1H, s, NH), 9.13 (1H, s, H3), 8.50 (1H, s, CH), 8.14 (1H, d, J = 7.5 Hz, H6'), 7.93 (1H, d, J = 8.0 Hz, H5), 7.72 (2H, m, H7 and H8), 7.68 (1H, d, J = 7.5 Hz, H3'), 7.52 (1H, dt, J = 8.0 and J = 1.3 Hz, H6), 7.48 (1H, t, J = 7.5 Hz, H4' or H5'), 7.33 (1H, t, J = 7.5 Hz, H4' or H5'). ¹³C NMR (100 MHz, DMSO-d₆): δ 150.1, 140.8, 140.0, 138.0, 136.4, 133.4, 133.0, 130.8, 130.3, 128.8, 128.0, 127.0, 126.3, 125.4, 122.6. MS/ESI (M – H): 324.9. IR (cm^–1, KBr): 3447 (N—H), 1582 (C═N).

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br32	0.39687 (4)	0.149640 (17)	0.675406 (7)	0.02693 (8)
N1	0.3115 (3)	0.41428 (13)	0.54660 (5)	0.0180 (3)
H1	0.3062	0.3488	0.5368	0.022*
N2	0.3658 (2)	0.43422 (14)	0.58896 (5)	0.0176 (3)
N11	0.2215 (2)	0.47221 (13)	0.47821 (5)	0.0167 (3)
N14	0.2243 (3)	0.68390 (13)	0.50878 (5)	0.0184 (3)
C3	0.3983 (3)	0.35361 (15)	0.61377 (6)	0.0168 (4)
H3	0.3805	0.2839	0.6027	0.020*
C12	0.2651 (3)	0.49677 (15)	0.51929 (6)	0.0162 (3)
C13	0.2626 (3)	0.60435 (15)	0.53486 (6)	0.0179 (4)
H13	0.2898	0.6179	0.5652	0.021*
C14A	0.1833 (3)	0.66023 (15)	0.46498 (6)	0.0170 (4)
C15	0.1456 (3)	0.74266 (16)	0.43479 (7)	0.0207 (4)
H15	0.1517	0.8143	0.4443	0.025*
C16	0.0998 (3)	0.71909 (17)	0.39149 (7)	0.0216 (4)
H16	0.0747	0.7747	0.3711	0.026*
C17	0.0899 (3)	0.61298 (17)	0.37716 (6)	0.0200 (4)
H17	0.0559	0.5976	0.3474	0.024*
C18	0.1293 (3)	0.53186 (16)	0.40601 (6)	0.0187 (4)
H18	0.1234	0.4606	0.3961	0.022*
C18A	0.1786 (3)	0.55420 (15)	0.45052 (6)	0.0160 (3)
C31	0.4632 (3)	0.37079 (16)	0.65936 (6)	0.0174 (4)
C32	0.4813 (3)	0.28886 (16)	0.69008 (6)	0.0193 (4)
C33	0.5554 (3)	0.30484 (18)	0.73237 (7)	0.0236 (4)
H33	0.5685	0.2472	0.7523	0.028*
C34	0.6097 (3)	0.40581 (19)	0.74502 (7)	0.0246 (4)
H34	0.6604	0.4176	0.7738	0.030*
C35	0.5904 (3)	0.48965 (18)	0.71575 (7)	0.0233 (4)
H35	0.6263	0.5590	0.7246	0.028*
C36	0.5186 (3)	0.47229 (17)	0.67353 (6)	0.0207 (4)
H36	0.5066	0.5303	0.6537	0.025*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br32	0.04257 (16)	0.01744 (12)	0.02080 (12)	−0.00066 (8)	−0.00043 (9)	0.00239 (7)
N1	0.0241 (8)	0.0147 (7)	0.0151 (7)	0.0001 (6)	−0.0017 (6)	−0.0008 (6)
N2	0.0176 (7)	0.0198 (8)	0.0156 (7)	0.0000 (6)	0.0004 (6)	−0.0011 (6)
N11	0.0181 (8)	0.0163 (7)	0.0157 (7)	−0.0004 (6)	0.0000 (6)	−0.0004 (6)
N14	0.0220 (8)	0.0169 (7)	0.0164 (7)	−0.0005 (6)	−0.0005 (6)	−0.0008 (6)
C3	0.0173 (9)	0.0173 (9)	0.0158 (8)	−0.0013 (7)	0.0006 (7)	−0.0002 (7)
C12	0.0161 (8)	0.0165 (8)	0.0159 (8)	0.0001 (7)	0.0019 (7)	0.0001 (7)
C13	0.0215 (9)	0.0170 (9)	0.0152 (8)	−0.0010 (7)	−0.0009 (7)	−0.0005 (7)
C14A	0.0168 (8)	0.0173 (9)	0.0169 (8)	−0.0008 (7)	0.0003 (7)	−0.0002 (7)
C15	0.0240 (10)	0.0165 (9)	0.0214 (9)	0.0022 (7)	0.0005 (8)	0.0002 (7)
C16	0.0242 (10)	0.0202 (9)	0.0203 (9)	0.0029 (8)	−0.0003 (8)	0.0050 (7)
C17	0.0198 (9)	0.0238 (10)	0.0164 (8)	0.0011 (8)	0.0003 (7)	−0.0008 (7)
C18	0.0203 (9)	0.0191 (9)	0.0167 (8)	0.0002 (7)	0.0003 (7)	−0.0027 (7)
C18A	0.0146 (8)	0.0179 (9)	0.0153 (8)	0.0003 (7)	0.0009 (7)	−0.0003 (7)
C31	0.0167 (9)	0.0196 (9)	0.0158 (8)	0.0017 (7)	0.0015 (7)	−0.0004 (7)
C32	0.0204 (9)	0.0185 (9)	0.0191 (8)	0.0013 (7)	0.0018 (7)	−0.0005 (7)
C33	0.0246 (10)	0.0283 (11)	0.0180 (9)	0.0043 (9)	−0.0010 (8)	0.0025 (8)
C34	0.0206 (10)	0.0357 (12)	0.0175 (9)	0.0026 (9)	−0.0024 (8)	−0.0036 (8)
C35	0.0219 (10)	0.0260 (10)	0.0218 (9)	−0.0016 (8)	0.0015 (8)	−0.0058 (8)
C36	0.0228 (10)	0.0210 (9)	0.0182 (9)	−0.0007 (8)	−0.0001 (7)	−0.0008 (7)

Geometric parameters (Å, º)

Br32—C32	1.907 (2)	C16—C17	1.410 (3)
N1—N2	1.357 (2)	C16—H16	0.9500
N1—C12	1.368 (2)	C17—C18	1.373 (3)
N1—H1	0.8800	C17—H17	0.9500
N2—C3	1.285 (3)	C18—C18A	1.415 (3)
N11—C12	1.314 (2)	C18—H18	0.9500
N11—C18A	1.364 (2)	C31—C32	1.396 (3)
N14—C13	1.305 (2)	C31—C36	1.406 (3)
N14—C14A	1.385 (2)	C32—C33	1.392 (3)
C3—C31	1.465 (3)	C33—C34	1.385 (3)
C3—H3	0.9500	C33—H33	0.9500
C12—C13	1.438 (3)	C34—C35	1.386 (3)
C13—H13	0.9500	C34—H34	0.9500
C14A—C15	1.409 (3)	C35—C36	1.387 (3)
C14A—C18A	1.410 (3)	C35—H35	0.9500
C15—C16	1.378 (3)	C36—H36	0.9500
C15—H15	0.9500
N2—N1—C12	119.49 (16)	C16—C17—H17	119.8
N2—N1—H1	120.3	C17—C18—C18A	120.11 (19)
C12—N1—H1	120.3	C17—C18—H18	119.9
C3—N2—N1	116.83 (17)	C18A—C18—H18	119.9
C12—N11—C18A	116.71 (16)	N11—C18A—C14A	121.81 (17)
C13—N14—C14A	116.85 (17)	N11—C18A—C18	118.90 (17)
N2—C3—C31	118.99 (18)	C14A—C18A—C18	119.28 (17)
N2—C3—H3	120.5	C32—C31—C36	116.74 (18)
C31—C3—H3	120.5	C32—C31—C3	122.82 (18)
N11—C12—N1	116.32 (17)	C36—C31—C3	120.38 (18)
N11—C12—C13	121.93 (17)	C33—C32—C31	122.4 (2)
N1—C12—C13	121.76 (16)	C33—C32—Br32	117.48 (16)
N14—C13—C12	122.25 (17)	C31—C32—Br32	120.15 (15)
N14—C13—H13	118.9	C34—C33—C32	119.2 (2)
C12—C13—H13	118.9	C34—C33—H33	120.4
N14—C14A—C15	119.74 (17)	C32—C33—H33	120.4
N14—C14A—C18A	120.37 (17)	C33—C34—C35	120.12 (19)
C15—C14A—C18A	119.89 (17)	C33—C34—H34	119.9
C16—C15—C14A	119.79 (19)	C35—C34—H34	119.9
C16—C15—H15	120.1	C34—C35—C36	120.0 (2)
C14A—C15—H15	120.1	C34—C35—H35	120.0
C15—C16—C17	120.49 (19)	C36—C35—H35	120.0
C15—C16—H16	119.8	C35—C36—C31	121.53 (19)
C17—C16—H16	119.8	C35—C36—H36	119.2
C18—C17—C16	120.39 (18)	C31—C36—H36	119.2
C18—C17—H17	119.8
C12—N1—N2—C3	176.54 (18)	C15—C14A—C18A—N11	177.40 (18)
N1—N2—C3—C31	178.07 (17)	N14—C14A—C18A—C18	177.62 (18)
C18A—N11—C12—N1	−178.78 (17)	C15—C14A—C18A—C18	−2.2 (3)
C18A—N11—C12—C13	1.7 (3)	C17—C18—C18A—N11	−178.44 (18)
N2—N1—C12—N11	177.24 (17)	C17—C18—C18A—C14A	1.1 (3)
N2—N1—C12—C13	−3.2 (3)	N2—C3—C31—C32	172.62 (19)
C14A—N14—C13—C12	0.7 (3)	N2—C3—C31—C36	−10.1 (3)
N11—C12—C13—N14	−2.7 (3)	C36—C31—C32—C33	−1.8 (3)
N1—C12—C13—N14	177.85 (19)	C3—C31—C32—C33	175.5 (2)
C13—N14—C14A—C15	−178.35 (19)	C36—C31—C32—Br32	176.50 (15)
C13—N14—C14A—C18A	1.9 (3)	C3—C31—C32—Br32	−6.2 (3)
N14—C14A—C15—C16	−178.26 (19)	C31—C32—C33—C34	1.4 (3)
C18A—C14A—C15—C16	1.5 (3)	Br32—C32—C33—C34	−176.96 (16)
C14A—C15—C16—C17	0.2 (3)	C32—C33—C34—C35	−0.1 (3)
C15—C16—C17—C18	−1.2 (3)	C33—C34—C35—C36	−0.8 (3)
C16—C17—C18—C18A	0.5 (3)	C34—C35—C36—C31	0.3 (3)
C12—N11—C18A—C14A	0.9 (3)	C32—C31—C36—C35	1.0 (3)
C12—N11—C18A—C18	−179.51 (18)	C3—C31—C36—C35	−176.46 (19)
N14—C14A—C18A—N11	−2.8 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N14^i	0.88	2.26	3.137 (2)	176
C15—H15···N11^ii	0.95	2.41	3.315 (3)	159

Symmetry codes: (i) −x+1/2, y−1/2, z; (ii) −x+1/2, y+1/2, z.

(3b) (E)-2-(2-(3-bromobenzylidene)hydrazinyl)quinoxaline

Crystal data

C15H11BrN4	F(000) = 1312
Mr = 327.19	Dx = 1.637 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71075 Å
Hall symbol: -C 2yc	Cell parameters from 3609 reflections
a = 32.781 (17) Å	θ = 3.0–30.2°
b = 6.875 (3) Å	µ = 3.09 mm^−1
c = 12.466 (6) Å	T = 100 K
β = 109.096 (11)°	Plate, orange
V = 2655 (2) Å^3	0.09 × 0.04 × 0.01 mm
Z = 8

Data collection

Rigaku Saturn724+ (2x2 bin mode) diffractometer	3036 independent reflections
Radiation source: Rotating Anode	2946 reflections with I > 2σ(I)
Confocal monochromator	Rint = 0.049
Detector resolution: 28.5714 pixels mm^-1	θmax = 27.5°, θmin = 3.3°
profile data from ω–scans	h = −42→42
Absorption correction: multi-scan CrystalClear-SM Expert 2.0 r13 (Rigaku, 2011)	k = −8→8
Tmin = 0.768, Tmax = 0.970	l = −16→16
22261 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.096	H-atom parameters constrained
S = 1.16	w = 1/[σ^2(Fo^2) + (0.0204P)^2 + 16.4208P] where P = (Fo^2 + 2Fc^2)/3
3036 reflections	(Δ/σ)max < 0.001
181 parameters	Δρmax = 1.59 e Å^−3
0 restraints	Δρmin = −0.79 e Å^−3

Special details

Experimental. Compound (3b): m.p. 504–505 K. ¹H NMR (400 MHz, DMSO-d₆): δ 11.81 (1H, s, NH), 9.14 (1H, s, H3), 8.11 (1H, s, CH), 7.98 (1H, s, H2'), 7.93 (1H, d, J = 8.1 Hz, H5), 7.76 (1H, d, J = 7.9 Hz, H4' or H6'), 7.71 (1H, dd, J = 8.1 and J = 1.8 Hz, H8), 7.68 (1H, t, J = 8.1 Hz, H7), 7.57 (1H, d, J = 7.9 Hz, H4' or H6'), 7.51 (1H, dt, J = 8.1 and J = 1.8 Hz, H6), 7.40 (1H, t, J = 7.9 Hz, H5'). ¹³C NMR (100 MHz, DMSO-d₆): δ 150.1, 140.8, 140.0, 138.0, 137.2, 136.5, 131.6, 130.8, 130.3, 128.8, 128.6, 126.2, 125.6, 125.3, 122.2. MS/ESI (M – H): 324.9. IR (cm^–1, KBr): 3435 (N—H), 1584 (C═N).

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br33	0.030885 (10)	0.19947 (7)	0.66065 (3)	0.03402 (13)
N1	0.23742 (7)	0.4670 (4)	0.5593 (2)	0.0156 (5)
H1	0.2482	0.4603	0.6337	0.019*
N2	0.19484 (7)	0.4269 (4)	0.5056 (2)	0.0151 (5)
N11	0.30366 (7)	0.5626 (4)	0.5551 (2)	0.0146 (5)
N14	0.27202 (8)	0.5647 (4)	0.3152 (2)	0.0152 (5)
C3	0.17290 (9)	0.3780 (4)	0.5703 (2)	0.0146 (5)
H3	0.1871	0.3665	0.6498	0.018*
C12	0.26348 (9)	0.5178 (4)	0.4969 (2)	0.0134 (5)
C13	0.24732 (9)	0.5190 (4)	0.3753 (2)	0.0155 (6)
H13	0.2180	0.4858	0.3375	0.019*
C14A	0.31455 (9)	0.6103 (4)	0.3732 (2)	0.0141 (5)
C15	0.34291 (9)	0.6578 (4)	0.3126 (2)	0.0168 (6)
H15	0.3325	0.6627	0.2320	0.020*
C16	0.38554 (9)	0.6969 (4)	0.3706 (2)	0.0173 (6)
H16	0.4046	0.7277	0.3298	0.021*
C17	0.40125 (9)	0.6916 (4)	0.4904 (2)	0.0178 (6)
H17	0.4308	0.7179	0.5296	0.021*
C18	0.37409 (9)	0.6487 (4)	0.5507 (2)	0.0167 (6)
H18	0.3849	0.6466	0.6313	0.020*
C18A	0.32999 (9)	0.6076 (4)	0.4933 (2)	0.0138 (5)
C31	0.12655 (9)	0.3398 (4)	0.5235 (2)	0.0154 (6)
C32	0.10457 (9)	0.2937 (4)	0.5986 (2)	0.0168 (6)
H32	0.1198	0.2824	0.6776	0.020*
C33	0.06027 (9)	0.2645 (5)	0.5570 (3)	0.0186 (6)
C34	0.03700 (10)	0.2796 (5)	0.4427 (3)	0.0224 (6)
H34	0.0067	0.2596	0.4157	0.027*
C35	0.05945 (10)	0.3251 (5)	0.3680 (3)	0.0241 (7)
H35	0.0442	0.3354	0.2890	0.029*
C36	0.10373 (10)	0.3557 (5)	0.4077 (2)	0.0190 (6)
H36	0.1185	0.3874	0.3561	0.023*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br33	0.01642 (16)	0.0626 (3)	0.02513 (18)	−0.00545 (16)	0.00962 (13)	0.00555 (17)
N1	0.0126 (11)	0.0217 (13)	0.0118 (11)	−0.0044 (10)	0.0031 (9)	−0.0001 (10)
N2	0.0125 (11)	0.0151 (12)	0.0163 (11)	−0.0007 (9)	0.0029 (9)	−0.0012 (9)
N11	0.0141 (11)	0.0157 (12)	0.0138 (11)	−0.0008 (9)	0.0043 (9)	0.0002 (9)
N14	0.0155 (11)	0.0150 (12)	0.0147 (11)	−0.0007 (9)	0.0045 (9)	−0.0005 (9)
C3	0.0152 (13)	0.0142 (13)	0.0143 (13)	0.0005 (11)	0.0047 (11)	−0.0005 (11)
C12	0.0156 (13)	0.0105 (13)	0.0151 (13)	−0.0004 (10)	0.0066 (10)	−0.0007 (10)
C13	0.0133 (12)	0.0170 (14)	0.0149 (13)	−0.0002 (11)	0.0028 (10)	−0.0004 (11)
C14A	0.0123 (12)	0.0133 (13)	0.0158 (13)	0.0001 (10)	0.0034 (10)	0.0010 (11)
C15	0.0179 (13)	0.0181 (14)	0.0148 (13)	−0.0013 (11)	0.0060 (11)	−0.0008 (11)
C16	0.0173 (13)	0.0168 (14)	0.0208 (14)	−0.0004 (11)	0.0105 (11)	0.0004 (12)
C17	0.0133 (13)	0.0188 (15)	0.0200 (14)	−0.0014 (11)	0.0036 (11)	−0.0008 (12)
C18	0.0155 (13)	0.0179 (14)	0.0150 (13)	−0.0005 (11)	0.0029 (11)	−0.0002 (11)
C18A	0.0154 (13)	0.0115 (13)	0.0146 (13)	0.0005 (10)	0.0051 (10)	0.0002 (10)
C31	0.0156 (13)	0.0128 (14)	0.0177 (13)	0.0011 (11)	0.0054 (11)	−0.0013 (11)
C32	0.0154 (13)	0.0205 (15)	0.0143 (13)	0.0005 (12)	0.0047 (11)	0.0007 (11)
C33	0.0161 (14)	0.0227 (16)	0.0196 (14)	0.0005 (11)	0.0093 (11)	0.0011 (12)
C34	0.0125 (13)	0.0297 (17)	0.0223 (15)	−0.0026 (12)	0.0020 (11)	−0.0019 (13)
C35	0.0185 (14)	0.0341 (19)	0.0171 (14)	0.0004 (13)	0.0021 (12)	−0.0005 (13)
C36	0.0194 (14)	0.0214 (15)	0.0164 (14)	0.0015 (12)	0.0061 (11)	0.0004 (12)

Geometric parameters (Å, º)

Br33—C33	1.900 (3)	C16—C17	1.413 (4)
N1—N2	1.364 (3)	C16—H16	0.9500
N1—C12	1.375 (4)	C17—C18	1.372 (4)
N1—H1	0.8800	C17—H17	0.9500
N2—C3	1.288 (4)	C18—C18A	1.416 (4)
N11—C12	1.316 (4)	C18—H18	0.9500
N11—C18A	1.367 (4)	C31—C32	1.392 (4)
N14—C13	1.310 (4)	C31—C36	1.395 (4)
N14—C14A	1.380 (4)	C32—C33	1.387 (4)
C3—C31	1.462 (4)	C32—H32	0.9500
C3—H3	0.9500	C33—C34	1.384 (4)
C12—C13	1.432 (4)	C34—C35	1.398 (4)
C13—H13	0.9500	C34—H34	0.9500
C14A—C15	1.414 (4)	C35—C36	1.388 (4)
C14A—C18A	1.415 (4)	C35—H35	0.9500
C15—C16	1.374 (4)	C36—H36	0.9500
C15—H15	0.9500
N2—N1—C12	119.9 (2)	C16—C17—H17	119.7
N2—N1—H1	120.0	C17—C18—C18A	120.3 (3)
C12—N1—H1	120.0	C17—C18—H18	119.9
C3—N2—N1	115.9 (2)	C18A—C18—H18	119.9
C12—N11—C18A	116.4 (2)	N11—C18A—C14A	121.7 (2)
C13—N14—C14A	117.5 (2)	N11—C18A—C18	119.2 (2)
N2—C3—C31	121.1 (3)	C14A—C18A—C18	119.0 (3)
N2—C3—H3	119.4	C32—C31—C36	119.5 (3)
C31—C3—H3	119.4	C32—C31—C3	118.1 (3)
N11—C12—N1	116.3 (2)	C36—C31—C3	122.3 (3)
N11—C12—C13	122.6 (2)	C33—C32—C31	119.4 (3)
N1—C12—C13	121.1 (2)	C33—C32—H32	120.3
N14—C13—C12	121.6 (3)	C31—C32—H32	120.3
N14—C13—H13	119.2	C34—C33—C32	122.1 (3)
C12—C13—H13	119.2	C34—C33—Br33	119.1 (2)
N14—C14A—C15	120.0 (3)	C32—C33—Br33	118.8 (2)
N14—C14A—C18A	120.1 (2)	C33—C34—C35	118.0 (3)
C15—C14A—C18A	119.9 (3)	C33—C34—H34	121.0
C16—C15—C14A	119.8 (3)	C35—C34—H34	121.0
C16—C15—H15	120.1	C36—C35—C34	120.9 (3)
C14A—C15—H15	120.1	C36—C35—H35	119.6
C15—C16—C17	120.5 (3)	C34—C35—H35	119.6
C15—C16—H16	119.8	C35—C36—C31	120.1 (3)
C17—C16—H16	119.8	C35—C36—H36	119.9
C18—C17—C16	120.5 (3)	C31—C36—H36	119.9
C18—C17—H17	119.7
C12—N1—N2—C3	179.1 (3)	N14—C14A—C18A—N11	−0.7 (4)
N1—N2—C3—C31	177.3 (3)	C15—C14A—C18A—N11	179.9 (3)
C18A—N11—C12—N1	178.1 (2)	N14—C14A—C18A—C18	178.0 (3)
C18A—N11—C12—C13	−1.2 (4)	C15—C14A—C18A—C18	−1.4 (4)
N2—N1—C12—N11	177.1 (3)	C17—C18—C18A—N11	179.1 (3)
N2—N1—C12—C13	−3.6 (4)	C17—C18—C18A—C14A	0.4 (4)
C14A—N14—C13—C12	0.6 (4)	N2—C3—C31—C32	−178.0 (3)
N11—C12—C13—N14	0.2 (5)	N2—C3—C31—C36	−0.6 (4)
N1—C12—C13—N14	−179.1 (3)	C36—C31—C32—C33	−0.1 (5)
C13—N14—C14A—C15	179.0 (3)	C3—C31—C32—C33	177.4 (3)
C13—N14—C14A—C18A	−0.4 (4)	C31—C32—C33—C34	0.0 (5)
N14—C14A—C15—C16	−177.9 (3)	C31—C32—C33—Br33	179.5 (2)
C18A—C14A—C15—C16	1.5 (4)	C32—C33—C34—C35	0.2 (5)
C14A—C15—C16—C17	−0.5 (5)	Br33—C33—C34—C35	−179.2 (3)
C15—C16—C17—C18	−0.5 (5)	C33—C34—C35—C36	−0.5 (5)
C16—C17—C18—C18A	0.5 (5)	C34—C35—C36—C31	0.4 (5)
C12—N11—C18A—C14A	1.5 (4)	C32—C31—C36—C35	−0.2 (5)
C12—N11—C18A—C18	−177.2 (3)	C3—C31—C36—C35	−177.5 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N14^i	0.88	2.14	3.024 (4)	177
C15—H15···N11^ii	0.95	2.61	3.399 (4)	141

Symmetry codes: (i) x, −y+1, z+1/2; (ii) x, −y+1, z−1/2.

(3c) (E)-2-(2-(4-bromobenzylidene)hydrazinyl)quinoxaline

Crystal data

C15H11BrN4	F(000) = 656
Mr = 327.19	Dx = 1.589 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71075 Å
Hall symbol: -P 2ybc	Cell parameters from 3105 reflections
a = 12.002 (5) Å	θ = 2.8–30.1°
b = 9.170 (3) Å	µ = 3.00 mm^−1
c = 12.617 (5) Å	T = 100 K
β = 100.004 (6)°	Plate, orange
V = 1367.5 (9) Å^3	0.09 × 0.05 × 0.01 mm
Z = 4

Data collection

Rigaku Saturn724+ (2x2 bin mode) diffractometer	2405 independent reflections
Radiation source: Rotating Anode	2302 reflections with I > 2σ(I)
Confocal monochromator	Rint = 0.056
Detector resolution: 28.5714 pixels mm^-1	θmax = 25.0°, θmin = 3.1°
profile data from ω–scans	h = −14→14
Absorption correction: multi-scan CrystalClear-SM Expert 3.1 b18 (Rigaku, 20112)	k = −10→9
Tmin = 0.774, Tmax = 0.971	l = −13→15
14729 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.062	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.113	H-atom parameters constrained
S = 1.17	w = 1/[σ^2(Fo^2) + (0.0153P)^2 + 6.7036P] where P = (Fo^2 + 2Fc^2)/3
2405 reflections	(Δ/σ)max < 0.001
182 parameters	Δρmax = 0.50 e Å^−3
0 restraints	Δρmin = −0.60 e Å^−3

Special details

Experimental. Compound (3c): m.p. 527–528 K. ¹H NMR (400 MHz, DMSO-d₆): δ 11.76 (1H, s, NH), 9.11 (1H, s, H3), 8.11 (1H, s, CH), 7.92 (1H, d, J = 8.1 Hz, H5), 7.73 (2H, d, J = 8.5 Hz, H2' and H6'), 7.68 (2H, m, H7 and H8), 7.63 (2H, d, J = 8.5 Hz, H3' and H5'), 7.50 (1H, dt, J = 8.1 and J = 2.0 Hz, H6). ¹³C NMR (100 MHz, DMSO-d₆): δ 150.2, 140.8, 140.5, 138.0, 136.4, 134.0, 131.7, 130.3, 128.7, 128.3, 126.2, 125.2, 122.2. MS/ESI (M – H): 324.9. IR (cm^–1, KBr): 3460 (N—H), 1591 (C═N).

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br34	1.03383 (4)	0.11361 (6)	0.64450 (5)	0.0380 (2)
N1	0.5232 (3)	0.6821 (4)	0.6006 (3)	0.0217 (9)
H1	0.4992	0.6824	0.6625	0.026*
N2	0.6097 (3)	0.5981 (4)	0.5850 (3)	0.0214 (9)
N11	0.3967 (3)	0.8554 (4)	0.5376 (3)	0.0206 (9)
N14	0.4617 (3)	0.8458 (4)	0.3233 (3)	0.0213 (9)
C3	0.6528 (4)	0.5203 (5)	0.6693 (4)	0.0194 (10)
H3	0.6215	0.5250	0.7335	0.023*
C14A	0.3788 (4)	0.9367 (5)	0.3421 (4)	0.0207 (10)
C18A	0.3481 (4)	0.9408 (5)	0.4495 (4)	0.0217 (11)
C12	0.4748 (4)	0.7701 (5)	0.5163 (4)	0.0197 (10)
C13	0.5067 (4)	0.7664 (5)	0.4074 (4)	0.0208 (10)
H13	0.5651	0.7006	0.3974	0.025*
C15	0.3266 (4)	1.0239 (5)	0.2532 (4)	0.0271 (12)
H15	0.3486	1.0171	0.1846	0.033*
C16	0.2455 (4)	1.1154 (6)	0.2713 (5)	0.0342 (13)
H16	0.2082	1.1758	0.2149	0.041*
C17	0.2142 (4)	1.1223 (6)	0.3777 (5)	0.0312 (13)
H17	0.1564	1.1888	0.3881	0.037*
C18	0.2638 (4)	1.0372 (6)	0.4661 (4)	0.0278 (12)
H18	0.2407	1.0454	0.5341	0.033*
C31	0.7468 (4)	0.4290 (5)	0.6633 (4)	0.0208 (10)
C32	0.7809 (4)	0.3297 (5)	0.7496 (4)	0.0236 (11)
H32	0.7430	0.3283	0.8098	0.028*
C33	0.8677 (4)	0.2376 (5)	0.7449 (4)	0.0236 (11)
H33	0.8924	0.1694	0.8007	0.028*
C34	0.9198 (4)	0.2469 (6)	0.6539 (4)	0.0275 (12)
C35	0.8898 (4)	0.3465 (6)	0.5683 (4)	0.0327 (13)
H35	0.9293	0.3485	0.5093	0.039*
C36	0.8030 (4)	0.4386 (6)	0.5729 (4)	0.0278 (12)
H36	0.7801	0.5080	0.5174	0.033*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br34	0.0191 (3)	0.0347 (3)	0.0591 (4)	0.0048 (2)	0.0033 (2)	−0.0129 (3)
N1	0.0168 (19)	0.027 (2)	0.023 (2)	0.0020 (17)	0.0066 (16)	−0.0008 (18)
N2	0.0177 (19)	0.021 (2)	0.025 (2)	0.0039 (17)	0.0035 (16)	−0.0005 (18)
N11	0.0133 (18)	0.023 (2)	0.026 (2)	0.0007 (16)	0.0034 (16)	−0.0032 (18)
N14	0.0174 (19)	0.024 (2)	0.024 (2)	−0.0045 (17)	0.0070 (17)	−0.0016 (18)
C3	0.014 (2)	0.019 (2)	0.026 (3)	−0.0003 (19)	0.004 (2)	−0.002 (2)
C14A	0.018 (2)	0.018 (2)	0.026 (3)	−0.0060 (19)	0.002 (2)	−0.002 (2)
C18A	0.014 (2)	0.019 (2)	0.030 (3)	−0.0046 (19)	−0.001 (2)	−0.001 (2)
C12	0.018 (2)	0.022 (3)	0.018 (3)	−0.005 (2)	0.0013 (19)	−0.003 (2)
C13	0.016 (2)	0.020 (2)	0.026 (3)	−0.0010 (19)	0.004 (2)	−0.002 (2)
C15	0.022 (3)	0.026 (3)	0.032 (3)	−0.006 (2)	0.001 (2)	0.006 (2)
C16	0.027 (3)	0.025 (3)	0.047 (4)	−0.004 (2)	−0.003 (2)	0.007 (3)
C17	0.020 (2)	0.022 (3)	0.050 (4)	0.000 (2)	0.002 (2)	−0.002 (3)
C18	0.021 (3)	0.027 (3)	0.036 (3)	−0.003 (2)	0.008 (2)	−0.006 (2)
C31	0.014 (2)	0.023 (3)	0.025 (3)	−0.0008 (19)	0.0012 (19)	−0.003 (2)
C32	0.020 (2)	0.022 (3)	0.029 (3)	−0.003 (2)	0.005 (2)	−0.001 (2)
C33	0.016 (2)	0.022 (3)	0.032 (3)	−0.003 (2)	0.002 (2)	−0.001 (2)
C34	0.020 (2)	0.026 (3)	0.036 (3)	0.003 (2)	0.003 (2)	−0.007 (2)
C35	0.026 (3)	0.041 (3)	0.034 (3)	−0.001 (2)	0.011 (2)	−0.005 (3)
C36	0.026 (3)	0.039 (3)	0.018 (3)	0.002 (2)	0.002 (2)	0.006 (2)

Geometric parameters (Å, º)

Br34—C34	1.854 (5)	C15—H15	0.9500
N1—N2	1.335 (5)	C16—C17	1.457 (8)
N1—C12	1.380 (6)	C16—H16	0.9500
N1—H1	0.8781	C17—C18	1.406 (7)
N2—C3	1.310 (6)	C17—H17	0.9500
N11—C12	1.285 (6)	C18—H18	0.9500
N11—C18A	1.402 (6)	C31—C32	1.424 (7)
N14—C13	1.323 (6)	C31—C36	1.426 (7)
N14—C14A	1.350 (6)	C32—C33	1.351 (6)
C3—C31	1.418 (6)	C32—H32	0.9500
C3—H3	0.9500	C33—C34	1.401 (7)
C14A—C15	1.430 (7)	C33—H33	0.9500
C14A—C18A	1.465 (7)	C34—C35	1.413 (7)
C18A—C18	1.386 (7)	C35—C36	1.350 (7)
C12—C13	1.489 (6)	C35—H35	0.9500
C13—H13	0.9500	C36—H36	0.9500
C15—C16	1.334 (7)
N2—N1—C12	117.2 (4)	C17—C16—H16	120.1
N2—N1—H1	121.1	C18—C17—C16	124.4 (5)
C12—N1—H1	121.6	C18—C17—H17	117.8
C3—N2—N1	113.7 (4)	C16—C17—H17	117.8
C12—N11—C18A	113.1 (4)	C18A—C18—C17	117.0 (5)
C13—N14—C14A	114.2 (4)	C18A—C18—H18	121.5
N2—C3—C31	118.9 (4)	C17—C18—H18	121.5
N2—C3—H3	120.5	C3—C31—C32	117.5 (4)
C31—C3—H3	120.5	C3—C31—C36	119.9 (4)
N14—C14A—C15	116.3 (4)	C32—C31—C36	122.6 (4)
N14—C14A—C18A	119.3 (4)	C33—C32—C31	119.1 (5)
C15—C14A—C18A	124.4 (4)	C33—C32—H32	120.4
C18—C18A—N11	116.8 (4)	C31—C32—H32	120.4
C18—C18A—C14A	117.6 (4)	C32—C33—C34	117.1 (5)
N11—C18A—C14A	125.7 (4)	C32—C33—H33	121.5
N11—C12—N1	114.7 (4)	C34—C33—H33	121.5
N11—C12—C13	121.4 (4)	C33—C34—C35	125.1 (5)
N1—C12—C13	123.8 (4)	C33—C34—Br34	116.8 (4)
N14—C13—C12	126.4 (4)	C35—C34—Br34	118.0 (4)
N14—C13—H13	116.8	C36—C35—C34	117.9 (5)
C12—C13—H13	116.8	C36—C35—H35	121.0
C16—C15—C14A	116.8 (5)	C34—C35—H35	121.0
C16—C15—H15	121.6	C35—C36—C31	118.1 (5)
C14A—C15—H15	121.6	C35—C36—H36	120.9
C15—C16—C17	119.8 (5)	C31—C36—H36	120.9
C15—C16—H16	120.1
C12—N1—N2—C3	178.6 (4)	C18A—C14A—C15—C16	0.6 (7)
N1—N2—C3—C31	−178.7 (4)	C14A—C15—C16—C17	−0.1 (7)
C13—N14—C14A—C15	−179.4 (4)	C15—C16—C17—C18	−0.3 (8)
C13—N14—C14A—C18A	0.8 (6)	N11—C18A—C18—C17	−179.5 (4)
C12—N11—C18A—C18	−179.3 (4)	C14A—C18A—C18—C17	0.5 (7)
C12—N11—C18A—C14A	0.7 (6)	C16—C17—C18—C18A	0.0 (7)
N14—C14A—C18A—C18	179.0 (4)	N2—C3—C31—C32	−170.7 (4)
C15—C14A—C18A—C18	−0.8 (7)	N2—C3—C31—C36	9.1 (7)
N14—C14A—C18A—N11	−1.0 (7)	C3—C31—C32—C33	177.8 (4)
C15—C14A—C18A—N11	179.1 (4)	C36—C31—C32—C33	−2.0 (7)
C18A—N11—C12—N1	−178.8 (4)	C31—C32—C33—C34	0.5 (7)
C18A—N11—C12—C13	−0.2 (6)	C32—C33—C34—C35	1.1 (8)
N2—N1—C12—N11	−175.8 (4)	C32—C33—C34—Br34	−176.8 (4)
N2—N1—C12—C13	5.6 (6)	C33—C34—C35—C36	−1.1 (8)
C14A—N14—C13—C12	−0.3 (7)	Br34—C34—C35—C36	176.8 (4)
N11—C12—C13—N14	0.0 (7)	C34—C35—C36—C31	−0.5 (7)
N1—C12—C13—N14	178.5 (4)	C3—C31—C36—C35	−177.8 (5)
N14—C14A—C15—C16	−179.2 (4)	C32—C31—C36—C35	2.0 (7)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N14^i	0.88	2.17	3.037 (6)	170
C16—H16···Br34^ii	0.95	2.87	3.712 (5)	148

Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) x−1, −y+3/2, z−1/2.