Two novel bis-azomethines derived from quinoxaline-2-carbaldehyde

The Schiff base compounds N,N'-bis­[(E)-quinoxalin-2-yl­meth­yl­idene]propane-1,3-diamine, C₂₁H₁₈N₆, (I), and N,N'-bis­[(E)-quinoxalin-2-ylmethyl­idene]butane-1,4-diamine, C₂₂H₂₀N₆, (II), crystallize in the monoclinic crystal system. These mol­ecules have crystallographically imposed symmetry. Compound (I) is located on a crystallographic twofold axis and (II) is located on an inversion centre. The mol­ecular conformations of these crystal structures are stabilized by aromatic [pi]-[pi] stacking inter­actions.

S1. Comment

The importance of Schiff bases is related to the common presence of a C═N bond in natural systems as well as to their easy formation and ability to form metal complexes with different structures. There exists a vast literature dealing with their biological activities including antibacterial (Karia & Parsania, 1999), antifungal (Singh & Dash, 1988), anticancer (Desai et al., 2001) and herbicidal activities (Samadhiya & Halve, 2001). Schiff bases are also becoming increasingly important in the dye, plastic, electronic and pharmaceutical industries. Multidentate Schiff base ligands and their metal complexes have been extensively studied for many years (Xavier et al., 2004). Schiff bases derived from quinoxaline-2-carbaldehyde and diamines constitute one of the most important ligand systems (Arun, Robinson et al., 2009). Interestingly, the size or length of the chain on the diamine clearly plays a role in the complexation with transition metal ions. Our results are of interest for the following reasons: (i) only a few crystal structures of free quinoxaline-based Schiff bases have been reported in the literature, (ii) many drug candidates bearing quinoxaline core structures are in clinical trials in antibacterial, antiviral (Harmenberg et al., 1991), anticancer and central nervous system therapeutic areas (Naylor et al., 1993), and (iii) Schiff base complexes act as catalysts in a variety of reactions including hydrogenation (Arun, Sridevi et al., 2009) and oxidation (Chittilappilly et al., 2008). In addition, the X-ray crystal structure of the Schiff base formed between quinoxaline-2-carbaldehyde and diamine has been reported by us for the first time (Varghese et al., 2009). This study is part of our ongoing effort to design and characterize an extensive series of Schiff bases and their complexes derived from quinoxaline-2-carbaldehyde. Keeping this goal in mind, we have synthesized two novel Schiff base compounds, namely N,N'-bis[(E)-quinoxalin-2-ylmethylidene]propane-1,3-diamine, (I), and N,N'-bis[(E)-quinoxalin-2-ylmethylidene]butane-1,4-diamine, (II), and we report here their crystal structures. This study of (I) and (II) was undertaken to obtain a clear understanding of the coordination geometry of these potential ligands.

In (I) (Fig. 1), one half of the molecule is related to the other half by a twofold axis passing through atom C11. The value of the N3—C10–C11—C10A torsion angle [180 (2)°] implies a trans alignment of the quinoxaline rings with respect to atom C11 (Philip et al., 2004). The quinoxaline rings are nearly planar, with a maximum deviation of 0.0021 Å from the mean plane. The N3—C10 and N3—C9 bond lengths are 1.459 (3) and 1.256 (3) Å, which are typical of C—N single- and C═N double-bond lengths, respectively. The N3—C9—C8, C9—N3—C10, N3—C10—C11, C10—C11—C10A angles are 122.3 (2), 116.7 (2), 110.3 (2) and 112.3 (3)°, respectively (Habibi et al., 2006). The crystal structure cohesion is reinforced by π–π stacking interactions forming a zigzag pattern along the c axis with a mean Cg1···Cg1(-x + 1/2, -y + 3/2, -z + 1) distance of 3.784 (14) Å (Cg1 is the centroid of the six-membered ring that includes atoms C2–C7; Fig. 2). The perpendicular distance between the rings is 3.4737 (8) Å.

For (II) (Fig. 3), the central C—C bond lies on a crystallographic inversion centre with the two C₁₁H₁₀N₃ groups in a trans orientation. The quinoxalidene rings and the C═N imine bonds are coplanar as supported by the C10—N3—C9—C8 angle [-179.2 (2)°]. The central N3—C10—C11—C11A fragment is planar [177.3 (3)°]. The quinoxaline rings are nearly planar with a maximum deviation of 0.0022 Å from the mean plane. The N3—C10 and N3—C9 bond lengths are 1.463 (3) and 1.255 (3) Å. The N3—C9—C8, C9—N3—C10, N3—C10—C11, C10—C11—C11A angles are 121.8 (2), 116.3 (2), 110.8 (2) and 113.1 (3)°, respectively (Habibi et al., 2006). The crystal structure of this compound is also stabilized by π–π stacking interactions along b axis with a mean centroid–centroid distance of 4.243 (18) Å (Fig. 4).

In conclusion, there is only a little variation in bond lengths and angles between the compounds (I) and (II). The values are comparable to those in related structures (Varghese et al., 2009; Varsha et al., 2009; Leeju et al., 2009). The crystal structures of these compounds are stabilized by π–π stacking interactions. For (I), the ring systems within the molecule are approximately perpendicular and those in (II) are parallel.

Related literature

For related literature, see: Arun, Robinson, Manju, Leeju, Varsha, Digna & Yusuff (2009); Arun, Sridevi, Robinson, Manju & Yusuff (2009); Chittilappilly et al. (2008); Desai et al. (2001); Habibi et al. (2006); Harmenberg et al. (1991); Karia & Parsania (1999); Leeju et al. (2009); Naylor et al. (1993); Philip et al. (2004); Samadhiya & Halve (2001); Singh & Dash (1988); Varghese et al. (2009); Varsha et al. (2009); Xavier et al. (2004).

S2. Experimental

Compounds (I) and (II) were synthesized by adopting a procedure similar to that for N,N'-bis[(E)-quinoxalin-2-ylmethylidene]ethane-1,2-diamine (Varghese et al., 2009). Instead of ethylenediamine, 1,3-diaminopropane and 1,4-diaminobutane were used for the synthesis of (I) and (II), respectively. Compounds (I) and (II) were recrystallized from methanol. Analysis calculated for C₂₁H₁₈N₆, (I): C 71.17, H 5.12, N 23.71%; found: C 70.86, H 5.21, N 23.59%. Analysis calculated for C₂₂H₂₀N₆, (II): C 71.52, H 5.47, N 22.81%; found: C 71.12, H 5.95, N 22.95%. The melting point of compound (I) is 431 K and that of (II) is 426 K. The infrared spectra of (I) and (II) exhibit a strong band at 1639 and 1637 cm^-1, respectively, due to the stretching of the azomethine bond in the Schiff base. Colourless single crystals of (I) and (II) suitable for X-ray diffraction were collected by slow evaporation of a solution in a 1:1 (v/v) mixture of dichloromethane and toluene.

S3. Refinement

For compound (I), space group C2/c, was uniquely assigned from the systematic absences. For compound (II), space group P2₁/c was selected and confirmed by the subsequent analysis. All H-atom parameters were refined freely [C—H = 0.93 (3)–1.03 (3) Å in (I) and 0.94 (3)–1.02 (3) Å in (II)]. [Please check changes]

Computing details

For both compounds, data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: publCIF (Westrip, 2009).

Figures

	Fig. 1. : A displacement ellipsoid plot (drawn at the 50% probability level) of (I) with the atomic labelling scheme. Atoms labelled with the suffix A are at the symmetry position (-x, y, 1/2 - z).
	Fig. 2. Figure: 2 π–π stacking interactions of (I), forming infinite chains in the [001] direction.
	Fig. 3. : A displacement ellipsoid plot (drawn at the 50% probability level) of (II) with the atomic labelling scheme. Atoms labelled with the suffix A are at the symmetry position (-x + 1, -y - 1, -z).
	Fig. 4. Figure: 4 π–π stacking interactions of (II), forming infinite chains in the [010] direction.

(I) N,N'-bis[(E)-quinoxalin-2-ylmethylidene]propane-1,3-diamine

Crystal data

C21H18N6	F(000) = 744
Mr = 354.41	Dx = 1.296 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1695 reflections
a = 10.371 (2) Å	θ = 2.6–28.2°
b = 9.180 (2) Å	µ = 0.08 mm^−1
c = 19.084 (4) Å	T = 298 K
β = 90.209 (4)°	Plate, colourless
V = 1817.0 (7) Å^3	0.45 × 0.35 × 0.12 mm
Z = 4

Data collection

Bruker SMART APEX CCD diffractometer	2086 independent reflections
Radiation source: fine-focus sealed tube	1695 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
ω and ϕ scans	θmax = 28.2°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	h = −13→12
Tmin = 0.964, Tmax = 0.990	k = −12→11
5277 measured reflections	l = −20→25

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)] = 0.076	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.169	All H-atom parameters refined
S = 1.18	w = 1/[σ^2(Fo^2) + (0.0539P)^2 + 1.6232P] where P = (Fo^2 + 2Fc^2)/3
2086 reflections	(Δ/σ)max < 0.001
159 parameters	Δρmax = 0.23 e Å^−3
0 restraints	Δρmin = −0.17 e Å^−3

Special details

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
N1	0.41189 (18)	0.8333 (2)	0.45574 (10)	0.0476 (5)
N2	0.23634 (17)	1.0385 (2)	0.51175 (9)	0.0449 (5)
N3	0.18137 (18)	1.1080 (2)	0.33187 (10)	0.0493 (5)
C1	0.3408 (2)	0.9176 (3)	0.41655 (12)	0.0459 (6)
C2	0.3974 (2)	0.8495 (2)	0.52678 (11)	0.0411 (5)
C3	0.4716 (2)	0.7635 (3)	0.57323 (13)	0.0515 (6)
C4	0.4577 (3)	0.7802 (3)	0.64355 (14)	0.0578 (7)
C5	0.3708 (3)	0.8820 (3)	0.67140 (13)	0.0564 (7)
C6	0.2979 (2)	0.9656 (3)	0.62794 (12)	0.0505 (6)
C7	0.3095 (2)	0.9523 (2)	0.55458 (11)	0.0408 (5)
C8	0.2524 (2)	1.0207 (2)	0.44395 (11)	0.0422 (5)
C9	0.1731 (2)	1.1136 (3)	0.39743 (12)	0.0478 (6)
C10	0.0934 (3)	1.2010 (3)	0.29216 (13)	0.0507 (6)
C11	0.0000	1.1091 (4)	0.2500	0.0509 (8)
H1	0.347 (2)	0.908 (2)	0.3673 (12)	0.042 (6)*
H3	0.528 (3)	0.693 (3)	0.5536 (14)	0.070 (8)*
H4	0.506 (2)	0.724 (3)	0.6750 (12)	0.049 (6)*
H5	0.362 (3)	0.890 (3)	0.7196 (14)	0.067 (8)*
H6	0.237 (2)	1.038 (3)	0.6460 (12)	0.052 (7)*
H9	0.117 (2)	1.176 (3)	0.4201 (13)	0.054 (7)*
H10A	0.149 (2)	1.260 (3)	0.2574 (13)	0.058 (7)*
H10B	0.048 (2)	1.269 (3)	0.3223 (13)	0.059 (7)*
H11A	−0.046 (3)	1.044 (3)	0.2810 (13)	0.066 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0452 (11)	0.0499 (11)	0.0478 (11)	0.0071 (9)	0.0016 (8)	−0.0062 (9)
N2	0.0433 (10)	0.0472 (11)	0.0442 (10)	0.0045 (8)	−0.0001 (8)	−0.0039 (8)
N3	0.0484 (11)	0.0549 (12)	0.0446 (11)	0.0055 (9)	−0.0058 (8)	−0.0033 (9)
C1	0.0444 (12)	0.0531 (13)	0.0402 (12)	0.0029 (11)	0.0007 (9)	−0.0071 (10)
C2	0.0362 (11)	0.0389 (11)	0.0483 (12)	−0.0040 (9)	−0.0018 (9)	−0.0018 (9)
C3	0.0488 (14)	0.0469 (13)	0.0589 (15)	0.0046 (11)	−0.0043 (11)	0.0016 (11)
C4	0.0642 (17)	0.0538 (15)	0.0553 (16)	0.0009 (13)	−0.0125 (12)	0.0126 (12)
C5	0.0658 (17)	0.0622 (16)	0.0412 (13)	−0.0040 (13)	−0.0023 (11)	0.0017 (12)
C6	0.0529 (14)	0.0541 (14)	0.0445 (13)	0.0002 (12)	0.0038 (10)	−0.0031 (11)
C7	0.0373 (11)	0.0412 (11)	0.0440 (12)	−0.0028 (9)	−0.0006 (9)	−0.0016 (9)
C8	0.0387 (11)	0.0439 (12)	0.0440 (12)	0.0005 (9)	−0.0009 (9)	−0.0045 (9)
C9	0.0462 (13)	0.0499 (13)	0.0473 (13)	0.0086 (11)	−0.0015 (10)	−0.0065 (11)
C10	0.0554 (15)	0.0503 (14)	0.0463 (13)	0.0064 (12)	−0.0089 (11)	−0.0022 (11)
C11	0.053 (2)	0.0471 (19)	0.053 (2)	0.000	−0.0079 (16)	0.000

Geometric parameters (Å, º)

N1—C1	1.303 (3)	C4—H4	0.94 (2)
N1—C2	1.373 (3)	C5—C6	1.358 (3)
N2—C8	1.315 (3)	C5—H5	0.93 (3)
N2—C7	1.366 (3)	C6—C7	1.411 (3)
N3—C9	1.256 (3)	C6—H6	0.98 (2)
N3—C10	1.459 (3)	C8—C9	1.478 (3)
C1—C8	1.419 (3)	C9—H9	0.93 (3)
C1—H1	0.95 (2)	C10—C11	1.514 (3)
C2—C3	1.413 (3)	C10—H10A	1.03 (3)
C2—C7	1.417 (3)	C10—H10B	0.98 (3)
C3—C4	1.359 (4)	C11—C10^i	1.514 (3)
C3—H3	0.95 (3)	C11—H11A	0.97 (2)
C4—C5	1.404 (4)
C1—N1—C2	116.03 (19)	C7—C6—H6	117.6 (13)
C8—N2—C7	116.41 (19)	N2—C7—C6	119.6 (2)
C9—N3—C10	116.7 (2)	N2—C7—C2	121.25 (19)
N1—C1—C8	123.4 (2)	C6—C7—C2	119.1 (2)
N1—C1—H1	118.7 (14)	N2—C8—C1	122.0 (2)
C8—C1—H1	117.9 (14)	N2—C8—C9	116.5 (2)
N1—C2—C3	119.9 (2)	C1—C8—C9	121.5 (2)
N1—C2—C7	120.97 (19)	N3—C9—C8	122.3 (2)
C3—C2—C7	119.2 (2)	N3—C9—H9	122.5 (15)
C4—C3—C2	119.8 (2)	C8—C9—H9	115.2 (15)
C4—C3—H3	122.3 (16)	N3—C10—C11	110.3 (2)
C2—C3—H3	117.8 (16)	N3—C10—H10A	107.0 (14)
C3—C4—C5	121.3 (2)	C11—C10—H10A	107.9 (14)
C3—C4—H4	120.9 (15)	N3—C10—H10B	111.9 (15)
C5—C4—H4	117.9 (15)	C11—C10—H10B	111.0 (15)
C6—C5—C4	120.1 (2)	H10A—C10—H10B	108 (2)
C6—C5—H5	120.3 (17)	C10—C11—C10^i	112.3 (3)
C4—C5—H5	119.5 (17)	C10—C11—H11A	109.4 (15)
C5—C6—C7	120.5 (2)	C10^i—C11—H11A	110.7 (16)
C5—C6—H6	121.9 (13)
C2—N1—C1—C8	−0.3 (3)	C3—C2—C7—N2	179.5 (2)
C1—N1—C2—C3	−179.4 (2)	N1—C2—C7—C6	−179.8 (2)
C1—N1—C2—C7	0.2 (3)	C3—C2—C7—C6	−0.3 (3)
N1—C2—C3—C4	179.6 (2)	C7—N2—C8—C1	0.0 (3)
C7—C2—C3—C4	0.1 (3)	C7—N2—C8—C9	179.81 (19)
C2—C3—C4—C5	−0.1 (4)	N1—C1—C8—N2	0.2 (4)
C3—C4—C5—C6	0.4 (4)	N1—C1—C8—C9	−179.6 (2)
C4—C5—C6—C7	−0.6 (4)	C10—N3—C9—C8	177.4 (2)
C8—N2—C7—C6	179.8 (2)	N2—C8—C9—N3	178.9 (2)
C8—N2—C7—C2	−0.1 (3)	C1—C8—C9—N3	−1.3 (4)
C5—C6—C7—N2	−179.3 (2)	C9—N3—C10—C11	−114.7 (2)
C5—C6—C7—C2	0.6 (4)	N3—C10—C11—C10	180.0 (2)
N1—C2—C7—N2	0.0 (3)

Symmetry code: (i) −x, y, −z+1/2.

(II) N,N'-bis[(E)-quinoxalin-2-ylmethylidene]butane-1,4-diamine

Crystal data

C22H20N6	F(000) = 388
Mr = 368.44	Dx = 1.298 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1748 reflections
a = 4.4819 (12) Å	θ = 2.7–27.9°
b = 5.3333 (14) Å	µ = 0.08 mm^−1
c = 39.456 (10) Å	T = 298 K
β = 92.266 (4)°	Plate, colourless
V = 942.4 (4) Å^3	0.75 × 0.35 × 0.14 mm
Z = 2

Data collection

Bruker SMART APEX CCD diffractometer	2132 independent reflections
Radiation source: fine-focus sealed tube	1748 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
ω and ϕ scans	θmax = 27.9°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	h = −3→5
Tmin = 0.942, Tmax = 0.989	k = −6→6
5220 measured reflections	l = −51→41

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)] = 0.071	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.186	All H-atom parameters refined
S = 1.14	w = 1/[σ^2(Fo^2) + (0.0658P)^2 + 0.4677P] where P = (Fo^2 + 2Fc^2)/3
2132 reflections	(Δ/σ)max < 0.001
167 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.17 e Å^−3

Special details

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
N1	−0.1263 (5)	0.3610 (4)	0.11524 (5)	0.0615 (6)
N2	0.2097 (4)	−0.0513 (4)	0.14068 (5)	0.0546 (5)
N3	0.3994 (4)	−0.0928 (4)	0.05486 (5)	0.0581 (6)
C1	0.0387 (5)	0.0910 (4)	0.16130 (5)	0.0497 (5)
C2	0.0304 (7)	0.0295 (6)	0.19610 (7)	0.0668 (7)
C3	−0.1367 (7)	0.1693 (6)	0.21702 (7)	0.0728 (8)
C4	−0.2975 (7)	0.3749 (6)	0.20463 (7)	0.0715 (8)
C5	−0.2954 (6)	0.4394 (6)	0.17123 (7)	0.0649 (7)
C6	−0.1263 (5)	0.2972 (4)	0.14894 (6)	0.0499 (5)
C7	0.0368 (6)	0.2207 (5)	0.09630 (6)	0.0577 (6)
C8	0.2068 (5)	0.0137 (4)	0.10858 (5)	0.0491 (5)
C9	0.3930 (5)	−0.1356 (5)	0.08610 (6)	0.0554 (6)
C10	0.5906 (6)	−0.2570 (6)	0.03541 (7)	0.0611 (7)
C11	0.4061 (6)	−0.4173 (5)	0.01103 (6)	0.0557 (6)
H2	0.144 (6)	−0.111 (6)	0.2039 (7)	0.076 (9)*
H3	−0.148 (6)	0.127 (6)	0.2400 (8)	0.077 (8)*
H4	−0.419 (7)	0.470 (6)	0.2196 (7)	0.086 (9)*
H5	−0.412 (6)	0.574 (6)	0.1629 (7)	0.069 (8)*
H8	0.037 (6)	0.260 (5)	0.0724 (7)	0.067 (7)*
H9	0.505 (5)	−0.266 (5)	0.0969 (6)	0.056 (7)*
H10A	0.718 (6)	−0.365 (6)	0.0506 (7)	0.075 (8)*
H10B	0.721 (6)	−0.143 (6)	0.0216 (7)	0.071 (8)*
H11A	0.274 (6)	−0.522 (6)	0.0237 (7)	0.076 (8)*
H11B	0.287 (6)	−0.306 (6)	−0.0034 (7)	0.080 (9)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0702 (13)	0.0580 (12)	0.0568 (12)	0.0166 (10)	0.0079 (9)	−0.0006 (10)
N2	0.0576 (11)	0.0531 (11)	0.0534 (11)	0.0065 (9)	0.0039 (9)	−0.0025 (9)
N3	0.0607 (12)	0.0601 (13)	0.0540 (12)	0.0130 (10)	0.0073 (9)	−0.0081 (9)
C1	0.0527 (12)	0.0499 (13)	0.0467 (12)	−0.0054 (10)	0.0051 (9)	−0.0061 (9)
C2	0.0803 (18)	0.0638 (17)	0.0567 (14)	0.0041 (15)	0.0085 (13)	0.0037 (13)
C3	0.090 (2)	0.080 (2)	0.0495 (14)	−0.0069 (17)	0.0173 (13)	−0.0035 (13)
C4	0.0740 (17)	0.0775 (19)	0.0645 (16)	−0.0013 (15)	0.0237 (13)	−0.0189 (15)
C5	0.0643 (16)	0.0621 (16)	0.0689 (16)	0.0071 (13)	0.0119 (13)	−0.0127 (13)
C6	0.0500 (12)	0.0464 (12)	0.0538 (12)	−0.0034 (10)	0.0068 (9)	−0.0062 (10)
C7	0.0683 (15)	0.0571 (14)	0.0482 (13)	0.0127 (12)	0.0075 (11)	−0.0004 (11)
C8	0.0483 (11)	0.0496 (13)	0.0495 (12)	0.0013 (10)	0.0034 (9)	−0.0057 (10)
C9	0.0552 (13)	0.0537 (14)	0.0571 (14)	0.0104 (11)	0.0009 (10)	−0.0029 (11)
C10	0.0604 (15)	0.0656 (16)	0.0578 (14)	0.0138 (13)	0.0104 (12)	−0.0088 (12)
C11	0.0570 (14)	0.0578 (15)	0.0533 (13)	0.0107 (12)	0.0162 (11)	−0.0024 (11)

Geometric parameters (Å, º)

N1—C7	1.302 (3)	C4—H4	0.96 (3)
N1—C6	1.373 (3)	C5—C6	1.405 (3)
N2—C8	1.313 (3)	C5—H5	0.94 (3)
N2—C1	1.369 (3)	C7—C8	1.416 (3)
N3—C9	1.255 (3)	C7—H8	0.96 (3)
N3—C10	1.463 (3)	C8—C9	1.476 (3)
C1—C6	1.402 (3)	C9—H9	0.95 (3)
C1—C2	1.414 (3)	C10—C11	1.509 (4)
C2—C3	1.359 (4)	C10—H10A	0.99 (3)
C2—H2	0.95 (3)	C10—H10B	1.02 (3)
C3—C4	1.390 (4)	C11—C11^i	1.517 (4)
C3—H3	0.94 (3)	C11—H11A	0.97 (3)
C4—C5	1.363 (4)	C11—H11B	0.97 (3)
C7—N1—C6	115.8 (2)	N1—C7—C8	123.9 (2)
C8—N2—C1	116.2 (2)	N1—C7—H8	117.2 (16)
C9—N3—C10	116.3 (2)	C8—C7—H8	118.9 (16)
N2—C1—C6	121.9 (2)	N2—C8—C7	121.4 (2)
N2—C1—C2	119.0 (2)	N2—C8—C9	116.9 (2)
C6—C1—C2	119.1 (2)	C7—C8—C9	121.6 (2)
C3—C2—C1	119.9 (3)	N3—C9—C8	121.8 (2)
C3—C2—H2	122.5 (17)	N3—C9—H9	122.8 (14)
C1—C2—H2	117.6 (17)	C8—C9—H9	115.3 (14)
C2—C3—C4	120.6 (3)	N3—C10—C11	110.8 (2)
C2—C3—H3	120.6 (18)	N3—C10—H10A	111.4 (15)
C4—C3—H3	118.8 (18)	C11—C10—H10A	110.1 (17)
C5—C4—C3	121.0 (3)	N3—C10—H10B	106.7 (16)
C5—C4—H4	119.2 (19)	C11—C10—H10B	107.9 (15)
C3—C4—H4	119.8 (19)	H10A—C10—H10B	110 (2)
C4—C5—C6	119.6 (3)	C10—C11—C11^i	113.1 (3)
C4—C5—H5	120.4 (17)	C10—C11—H11A	109.2 (17)
C6—C5—H5	119.9 (17)	C11^i—C11—H11A	108.9 (17)
N1—C6—C1	120.7 (2)	C10—C11—H11B	107.6 (18)
N1—C6—C5	119.5 (2)	C11^i—C11—H11B	108.8 (17)
C1—C6—C5	119.7 (2)	H11A—C11—H11B	109 (2)
C8—N2—C1—C6	−1.0 (3)	C4—C5—C6—N1	179.5 (2)
C8—N2—C1—C2	179.5 (2)	C4—C5—C6—C1	−0.1 (4)
N2—C1—C2—C3	179.7 (2)	C6—N1—C7—C8	0.0 (4)
C6—C1—C2—C3	0.2 (4)	C1—N2—C8—C7	0.3 (3)
C1—C2—C3—C4	−0.8 (5)	C1—N2—C8—C9	179.20 (19)
C2—C3—C4—C5	0.9 (5)	N1—C7—C8—N2	0.2 (4)
C3—C4—C5—C6	−0.5 (4)	N1—C7—C8—C9	−178.6 (2)
C7—N1—C6—C1	−0.7 (3)	C10—N3—C9—C8	−179.2 (2)
C7—N1—C6—C5	179.7 (2)	N2—C8—C9—N3	178.1 (2)
N2—C1—C6—N1	1.2 (3)	C7—C8—C9—N3	−3.1 (4)
C2—C1—C6—N1	−179.3 (2)	C9—N3—C10—C11	113.4 (3)
N2—C1—C6—C5	−179.2 (2)	N3—C10—C11—C11^i	177.3 (3)
C2—C1—C6—C5	0.3 (3)

Symmetry code: (i) −x+1, −y−1, −z.