3,6-Di­chloro-4-[2-(4-thia­morpholino)­ethanesulfanyl]­pyridazine and 3,6-bis­(pyrazol-1-yl)-4-[2-(4-thia­mor­pho­lino)­ethanesulfanyl]­pyridazine

The trans-trans conformations adopted by the derivatized bis­(bidentate) chelating N₄-donor ligand 3,6-bis­(pyrazol-1-yl)-4-[2-(4-thia­morpholino)­ethanesulfanyl]­pyridazine, C₁₆H₁₉N₇S₂, and an intermediate in its formation, 3,6-di­chloro-4-[2-(4-thia­morpholino)­ethanesulfanyl]­pyridazine, C₁₀H₁₃Cl₂N₃S₂, con­trast with the cis-cis conformation found previously for 3,6-bis­(thio­phen-2-yl)­pyridazine [Ackers, Blake, Hill & Hubberstey (2002). Acta Cryst. C58, o640-o641], which places all four heteroatoms on the same side of the mol­ecule.

S1. Comment

Pyridazines substituted in the 3- and 6-positions with N-donor ligands (e.g. pyrazole, 2-pyridine, 2-aminopyridine and 2-mercaptopyridine) can act as tetradentate N₄-donor ligands in a bis(bidentate) chelating fashion. These compounds are ideal for the generation of multinuclear coordination complexes with relatively short internuclear separations [d(M···M) ca 3.6 Å]. Many dinuclear copper(II) complexes, often with ancillary hydroxide or halide bridges, have been prepared (Chen et al., 1993a,b; Tandon et al., 1995, 1992; Thompson et al., 1985; Xu et al., 2000; Zhang et al., 1995) because of interest in their magnetic behaviour. By using metal centres predisposed to tetrahedral geometries, diverse molecular grids (2 × 2 and 2 × 3) have also been generated (Baxter et al., 1997; Youinou et al., 1992). Our own work with these ligands (Hubberstey & Russell, 1995) has concentrated on their use to generate trinuclear copper(I) complexes as small-molecule analogues of the trinuclear active sites in copper proteins such as ascorbate oxidases and laccases.

In an effort to develop this chemistry and generate molecules with linked mononuclear and trinuclear sites, as is the case in ascorbate oxidases (Messerschmidt et al., 1989, 1992, 1993) and laccases (Bertrand et al., 2002; Ducros et al., 1998, 2001; Hakulinen et al., 2002), we have attempted to attach to the pyridazine backbone potential mononuclear ligating centres, which can be either mono- or multidentate.

Following Hiller et al. (1968), who reported that the 4-position of 3,4,6-trichloropyridazine was much more sensitive to nucleophilic substitution than the 3- or 6-positions, we have been able to selectively add the potentially tridentate chelating moiety 2-(thiomorpholino)ethanethiol to the 4-position of the pyridazine ring and subsequently replace the remaining Cl atoms with pyrazole moieties, forming first 3,6-dichloro-4-[2-(thiomorpholino)ethanethiolato]pyridazine, (I), and secondly 3,6-bis(pyrazol-1-yl)-4-[2-(thiomorpholino)ethanethiolato]pyridazine, (II).

The molecular structures of (I) and (II) [Figs. 1(a) and 1(b), respectively] can be compared with that of the tris(pyrazole)-substituted molecule 3,4,6-tris(pyrazol-1-yl)pyridazine [(III); Fig. 1c; Blake et al., 2002]. It is clear that (I), an intermediate in the synthesis of (II), is not a potential ligand, unlike (II) and (III), for which two noteworthy points emerge. Firstly, the pyridazine and pyrazole rings are not coplanar, giving buckled molecules and, secondly, the rings adopt a trans–trans conformation, which contrasts with the cis–cis conformation adopted when the rings act? as tetradentate N₄-donor ligands in a bis(bidentate) chelating fashion.

The deviation from planarity in (II) is relatively small, as illustrated by the dihedral angles between the pyridazine ring and the two substituent pyrazole rings [13.5 (2) and 23.3 (1)°]. The molecules of (III) are much more buckled. Although the 6-substituted pyrazole ring is almost coplanar with the pyridazine ring [dihedral angle 5.5 (2)°], the 3- and 4-substituted pyrazole rings are severely bent out of the plane of the pyridazine ring [dihedral angles 40.2 and 51.2°, respectively]. Although the molecular structure of 3,6-bis(pyrazol-1-yl)pyridazine, (IV), has yet to be investigated in the solid state, it is predicted to be planar by analogy with similar multi-ring species, including 3,6-bis(thiophen-2-yl)pyridazine (Ackers et al., 2002) and 2,2'-bipyridine (Howard, 1996). Since detailed calculations on isolated 2,2'-bipyridine molecules show the most stable arrangement to be that with a dihedral angle between the planes of the aromatic rings of 44.9° (Howard, 1996), the fact that it? adopts a planar trans-arrangement in the solid state can be attributed to the more favourable packing interactions associated with planar rather than non-planar molecules. Deviation from planarity in (II) and (III) is thus attributed to steric conflict. That in (III) can be attributed to the interactions between the adjacent pyrazole substituents on the 3- and 4-positions of the pyridazine ring. The substituent in the 3-position of (II), 2-(thiomorpholino)ethanethiol, although longer than pyrazole, is much less sterically demanding, leading to a much flatter molecular arrangement.

The trans–trans conformations adopted by (II) (Fig. 1 b) and (III) (Fig. 1c) contrast with that found for 3,6-bis(thiophen-2-yl)pyridazine, for which all four heteroatoms are located on the same side of the molecule, giving a cis–cis conformation (Ackers et al., 2002). These apparently conflicting arrangements are, however, consistent with the results of semi-empirical AM calculations using the PC Spartan Plus suite of programs (Wavefunction, 2002). These results confirm that the lowest energy conformations of (IV) and of 3,6-bis(thiophen-2-yl)pyridazine, (V), are the trans–trans and cis–cis conformers, respectively. Relative enthalpies of formation are given in Table 1. Interestingly, the stabilization of the trans–trans iosomer of (IV) over the cis–cis form (−32.01 kJ mol⁻¹) is similar to the difference between the enthalpies of formation of the trans and cis versions of planar 2,2'-bipyridine (32.3 kJ mol⁻¹), for which the trans conformer is the more stable (Howard, 1996; see Table 1).

The greater stability of the trans–trans conformer of (IV) relative to the cis–cis conformer may be attributed to (i) the presence of four intramolecular C—H···N hydrogen bonds in the former and (ii) steric repulsion between the H atoms attached to atoms C4 and C35 and attached to atoms C5 and C65 in the latter. Although an explanation for the different behaviour of (IV) and (V) is not immediately obvious, the fact that twice as many intramolecular C—H···N hydrogen bonds occur in the trans–trans version of (IV) (four) than in the corresponding conformer of (V) (two) may be significant.

The more favourable packing interactions associated with planar rather than non-planar molecules alluded to earlier may be traced to π–π-stacking forces, as the extended stuctures of both (I) and (II) involve offset face-to-face interactions (Hunter & Sanders, 1990; Hunter et al., 2001). An analysis of the extended structure of (I) reveals a columnar arrangement of molecules, stacked in the b direction and held together by π–π-stacking interactions between their aromatic moieties (Fig. 2). The perpendicular separations between the aromatic moieties, which are crystallographically constrained to be parallel, average 3.43 (3) Å (range 3.385–3.466 Å) and 3.58 (3) Å (range 3.539–3.620 Å). The columns are linked by very long S···S contacts, similar in length [3.973 (2) Å] to those linking the molecules in the extended structure of 3,6-bis(thiophen-2-yl)pyridazine [3.980 (2) Å, Ackers et al., 2002], to give a two-dimensional architecture parallel to the (001) plane (Fig. 3).

An analysis of the extended structure of (II) shows the formation of dimers through relatively short S···S interactions [3.246 (2) Å, Fig. 4]. The dimers, facing alternate directions, stack along the a direction (Fig. 5), utilizing weak offset face-to-face π–π interactions between pyridazine rings [perpendicular separation 3.7 (2) Å, range 3.43–3.95 Å].

As the three rings in the structure of (II) depart only marginally from coplanarity, it is anticipated that (II) will be able to act as a bis(bidentate) chelating ligand in much the same way as the non-derivatized species. However, owing to the severe buckling of the structure of (III), which results from steric repulsion between the 3- and 4-substituted pyrazole rings, it will probably not be possible for (III) to act similarly. Consequently, our future efforts to generate small-molecule analogues of multinuclear copper proteins will concentrate on the use of (II) rather than (III).

S2. Experimental

3,6-Bis(pyrazol-1-yl)-4-[2-(thiomorpholino)ethanethiolato]pyridazine

Sodium hydride (0.071 g, 2.96 mmol) was added to a solution of pyrazole (0.120 g, 1.76 mmol) in pre-dried tetrahydrofuran (50 cm³). After stirring the mixture for 20 min, 3,6-dichloro-4-[2-(thiomorpholino)ethanethiolato]pyridazine (0.275 g, 0.89 mmol) was added to the solution and the mixture was heated at reflux for 4 h. After cooling to room temperature, the solvent was removed, and the resultant solid was dissolved in dichloromethane (50 cm³) and washed with water (3 x 50 cm³). The organic layer was dried over magnesium sulfate and the solvent was removed to give a thick pale-brown oil, which was recrystallized from ethanol to yield pale-brown needles (yield 0.070 g, 0.187 mmol, 21%). Analysis found: C 50.95, H 5.00, N 25.85%; calculated for C₁₆H₁₉N₇S₂: C 51.45, H 5.15, N 26.25%. IR (KBr disc, ν / cm⁻¹): 2899 m, 1561 s, 1518 s, 1449 s, 1392 s, 1262 m, 1200 m, 1108 s, 1091 s, 1034 s, 1018 s, 950 m, 932 s, 875 m, 825 s, 805 s, 765 s, 634 m, 606 m, 534 m. ¹H-NMR (CDCl₃, p.p.m.): 2.69–2.86 (m, 10H), 3.18 (t, 2H), 6.57 (m, 2H) 7.81 (q, 1H), 7.88 (q, 1H), 8.23 (s, 1H), 8.49 (q, 1H), 8.74 (q, 1H). FAB-MS (m/z) 374 [C₁₆H₁₉N₇S₂+H]⁺.

3,6-Dichloro-4-[2-(thiomorpholino)ethanethiolato]pyridazine

Potassium carbonate (0.21 g, 1.54 mmol) was added to a stirred solution of 2-(thiomorpholino)ethanethiol (0.5 g, 3.07 mmol), which was previously synthesized by treatment of ethylene sulfide with thiomorpholine, in degassed MeCN (50 cm³). After 15 min, 3,4,6-trichloropyridazine (0.56 g, 3.07 mmol) was added and the mixture was heated at reflux for 20 h. The white precipitate that appeared on cooling was removed by filtration, washed with water and recrystallized from ethanol as pale-brown needles (yield 0.69 g, 2.22 mmol, 72%). Analysis found: C 38.20, H 4.05, N 13.10%; calculated for C₁₀H₁₃Cl₂N₃S₂: C 38.70, H 4.20, N 13.55%. IR (KBr disc, ν / cm⁻¹): 3069 m, 2929 m, 2808 s, 2772 m, 1518 s, 1420 m, 1373 s, 1339 s, 1319 s, 1296 s, 1289 s, 1227 m, 1201 m, 1164 m, 1138 s, 1115 s, 1076 m, 1048 m, 981 s, 963 m, 943 m, 886 m, 868 m, 840 s, 748 m, 662 m, 579 s, 424 m. ¹H-NMR (CDCl₃, p.p.m.): 2.67–2.84 (m, 10H), 3.10 (t, 2H), 7.29 (s, 1H). EI—MS (m/z) 309 [C₁₀H₁₃Cl₂N₃S₂]⁺.

S3. Refinement

In (I), H atoms were located from ΔF syntheses and refined positionally but with U_iso values of 1.2U_eq(C). In (II), H atoms were first located from ΔF syntheses, then placed in idealized positions and refined using a riding model, with aromatic and aliphatic C—H distances constrained to be 0.96 and 0.99 Å, respectively, and with U_iso(H) values of 1.2U_eq(C).

Computing details

For both compounds, data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT and SHELXTL (Bruker, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997). Molecular graphics: CAMERON (Watkin et al., 1993) for (I); CAMERON (Watkin et al., 1996) for (II). For both compounds, software used to prepare material for publication: SHELXL97; PLATON (Spek, 2003).

Figures

	Fig. 1. A view of the molecular structures and atom-numbering schemes of (a) 3,6-dichloro-4-[2-(thiomorpholino)ethanethiolato]pyridazine, (I), (b) 3,6-bis(pyrazol-1-yl)-4-[2-(thiomorpholino)ethanethiolato]pyridazine, (II), and (c) 3,4,6-tris(pyrazol-1-yl)pyridazine, (III). Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as spheres of arbitrary radii.
	Fig. 2. A projection of the structure of (I) onto the (010) plane, showing the π–π-stacking interactions and intermolecular S···S contacts (S, large pale-grey circles; Cl, large dark-grey circles; C, intermediate black circles; N, intermediate dark-grey circles; H, small pale-grey circles).
	Fig. 3. A projection of the structure of (I) onto the (100) plane, showing the π–π-stacking interactions and intermolecular S···S contacts (S, large pale-grey circles; Cl, large dark-grey circles; C, intermediate black circles; N, intermediate dark-grey circles; H, small pale-grey circles).
	Fig. 4. A view of the structure of (II), showing the intermolecular S···S contact generating the dimeric arrangement (S, large pale-grey circles; C, intermediate black circles; N, intermediate dark-grey circles; H, small pale-grey circles).
	Fig. 5. A projection of the structure of (II) onto the (010) plane, showing the stacking of the dimers along the a direction. (S, large pale-grey circles; C, intermediate black circles; N, intermediate dark-grey circles; H, small pale-grey circles).

(I) 3,6-Dichloro-4-[2-(4-thiamorpholino)ethanesulfanyl]pyridazine

Crystal data

C10H13Cl2N3S2	Dx = 1.584 Mg m^−3
Mr = 310.26	Melting point: unknown K
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 12.097 (3) Å	Cell parameters from 3123 reflections
b = 7.021 (2) Å	θ = 2.7–28.1°
c = 15.425 (4) Å	µ = 0.80 mm^−1
β = 96.645 (5)°	T = 150 K
V = 1301.2 (6) Å^3	Triangular plate, colourless
Z = 4	0.27 × 0.25 × 0.06 mm
F(000) = 640

Data collection

Bruker SMART1000 CCD area detector diffractometer	3042 independent reflections
Radiation source: normal-focus sealed tube	2250 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.046
ω scans	θmax = 28.7°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→15
Tmin = 0.721, Tmax = 0.928	k = −9→9
8156 measured reflections	l = −20→19

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.033	H-atom parameters constrained
wR(F^2) = 0.089	w = 1/[σ^2(Fo^2) + (0.054P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.96	(Δ/σ)max = 0.001
3042 reflections	Δρmax = 0.38 e Å^−3
154 parameters	Δρmin = −0.29 e Å^−3
0 restraints

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.

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

	x	y	z	Uiso*/Ueq
N1	0.49032 (15)	0.2709 (2)	1.17487 (11)	0.0297 (4)
N2	0.39942 (15)	0.2629 (2)	1.11561 (12)	0.0298 (4)
C3	0.41164 (16)	0.2497 (2)	1.03281 (14)	0.0259 (4)
C4	0.51381 (16)	0.2475 (2)	0.99670 (13)	0.0225 (4)
C5	0.60676 (17)	0.2589 (2)	1.05828 (12)	0.0241 (4)
H5	0.6785	0.2608	1.0421	0.029*
C6	0.58765 (18)	0.2675 (2)	1.14509 (13)	0.0256 (4)
Cl31	0.28779 (4)	0.23419 (8)	0.96341 (4)	0.03605 (15)
Cl61	0.70171 (4)	0.27187 (7)	1.22518 (3)	0.03215 (14)
S41	0.50956 (4)	0.22526 (7)	0.88406 (3)	0.02329 (13)
C41	0.65532 (16)	0.2452 (3)	0.86664 (13)	0.0257 (4)
H41A	0.6773	0.3780	0.8655	0.031*
H41B	0.7022	0.1813	0.9130	0.031*
C42	0.66641 (15)	0.1511 (3)	0.77915 (12)	0.0244 (4)
H42A	0.7329	0.1983	0.7567	0.029*
H42B	0.6746	0.0147	0.7875	0.029*
N11	0.57023 (13)	0.1888 (2)	0.71576 (10)	0.0222 (3)
C12	0.57247 (15)	0.3798 (3)	0.67809 (12)	0.0247 (4)
H12A	0.6279	0.3842	0.6374	0.030*
H12B	0.5936	0.4714	0.7241	0.030*
C13	0.45981 (16)	0.4335 (3)	0.63099 (12)	0.0278 (4)
H13A	0.4627	0.5634	0.6099	0.033*
H13B	0.4045	0.4283	0.6718	0.033*
S14	0.41816 (4)	0.27758 (8)	0.54026 (3)	0.03046 (14)
C15	0.43974 (17)	0.0551 (3)	0.59848 (13)	0.0288 (4)
H15A	0.3841	0.0423	0.6386	0.035*
H15B	0.4297	−0.0493	0.5571	0.035*
C16	0.55399 (16)	0.0408 (3)	0.64895 (12)	0.0253 (4)
H16A	0.5628	−0.0835	0.6764	0.030*
H16B	0.6100	0.0537	0.6092	0.030*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0368 (10)	0.0239 (8)	0.0300 (9)	0.0015 (7)	0.0110 (8)	−0.0002 (7)
N2	0.0317 (10)	0.0266 (9)	0.0331 (10)	0.0046 (7)	0.0122 (8)	0.0031 (7)
C3	0.0255 (10)	0.0208 (10)	0.0319 (11)	0.0027 (7)	0.0060 (8)	0.0019 (7)
C4	0.0249 (10)	0.0172 (9)	0.0257 (9)	0.0019 (7)	0.0047 (8)	0.0019 (7)
C5	0.0254 (10)	0.0220 (9)	0.0254 (10)	0.0012 (7)	0.0048 (8)	−0.0006 (7)
C6	0.0330 (11)	0.0194 (9)	0.0250 (10)	0.0013 (7)	0.0055 (8)	−0.0015 (7)
Cl31	0.0192 (3)	0.0477 (3)	0.0412 (3)	0.0040 (2)	0.0032 (2)	0.0037 (2)
Cl61	0.0354 (3)	0.0400 (3)	0.0206 (2)	0.0005 (2)	0.0012 (2)	−0.00433 (19)
S41	0.0207 (2)	0.0268 (2)	0.0222 (2)	0.00086 (18)	0.00184 (18)	0.00075 (18)
C41	0.0192 (10)	0.0339 (11)	0.0237 (10)	−0.0013 (7)	0.0013 (7)	−0.0009 (8)
C42	0.0213 (10)	0.0289 (10)	0.0227 (9)	0.0030 (8)	0.0017 (8)	0.0000 (8)
N11	0.0224 (8)	0.0224 (8)	0.0213 (8)	0.0012 (6)	0.0004 (6)	−0.0012 (6)
C12	0.0254 (11)	0.0244 (10)	0.0241 (9)	−0.0013 (8)	0.0021 (8)	−0.0012 (7)
C13	0.0284 (11)	0.0260 (10)	0.0289 (10)	0.0029 (8)	0.0031 (8)	0.0001 (8)
S14	0.0269 (3)	0.0390 (3)	0.0243 (3)	0.0027 (2)	−0.0019 (2)	0.0001 (2)
C15	0.0289 (11)	0.0317 (10)	0.0261 (10)	−0.0049 (8)	0.0049 (8)	−0.0055 (8)
C16	0.0291 (11)	0.0237 (9)	0.0233 (9)	0.0019 (8)	0.0040 (8)	−0.0026 (7)

Geometric parameters (Å, º)

N1—N2	1.347 (3)	C42—H42B	0.9700
N1—C6	1.313 (3)	N11—C16	1.460 (2)
N2—C3	1.306 (3)	N11—C12	1.463 (2)
C3—C4	1.413 (3)	C12—C13	1.516 (3)
C3—CL31	1.741 (2)	C12—H12A	0.9700
C4—C5	1.388 (3)	C12—H12B	0.9700
C4—S41	1.739 (2)	C13—S14	1.802 (2)
C5—C6	1.386 (3)	C13—H13A	0.9700
C5—H5	0.9300	C13—H13B	0.9700
C6—CL61	1.743 (2)	S14—C15	1.806 (2)
S41—C41	1.820 (2)	C15—C16	1.509 (3)
C41—C42	1.522 (3)	C15—H15A	0.9700
C41—H41A	0.9700	C15—H15B	0.9700
C41—H41B	0.9700	C16—H16A	0.9700
C42—N11	1.455 (2)	C16—H16B	0.9700
C42—H42A	0.9700
C6—N1—N2	117.16 (17)	C42—N11—C12	112.55 (15)
C3—N2—N1	119.38 (17)	C16—N11—C12	112.26 (15)
N2—C3—C4	126.1 (2)	N11—C12—C13	111.19 (15)
N2—C3—CL31	114.77 (15)	N11—C12—H12A	109.4
C4—C3—CL31	119.11 (16)	C13—C12—H12A	109.4
C5—C4—C3	113.95 (19)	N11—C12—H12B	109.4
C5—C4—S41	128.09 (16)	C13—C12—H12B	109.4
C3—C4—S41	117.94 (15)	H12A—C12—H12B	108.0
C6—C5—C4	116.81 (19)	C12—C13—S14	112.09 (13)
C6—C5—H5	121.6	C12—C13—H13A	109.2
C4—C5—H5	121.6	S14—C13—H13A	109.2
N1—C6—C5	126.55 (19)	C12—C13—H13B	109.2
N1—C6—CL61	114.85 (15)	S14—C13—H13B	109.2
C5—C6—CL61	118.60 (16)	H13A—C13—H13B	107.9
C4—S41—C41	102.91 (9)	C13—S14—C15	97.35 (9)
C42—C41—S41	106.48 (13)	C16—C15—S14	112.66 (14)
C42—C41—H41A	110.4	C16—C15—H15A	109.1
S41—C41—H41A	110.4	S14—C15—H15A	109.1
C42—C41—H41B	110.4	C16—C15—H15B	109.1
S41—C41—H41B	110.4	S14—C15—H15B	109.1
H41A—C41—H41B	108.6	H15A—C15—H15B	107.8
N11—C42—C41	111.79 (15)	N11—C16—C15	110.92 (15)
N11—C42—H42A	109.3	N11—C16—H16A	109.5
C41—C42—H42A	109.3	C15—C16—H16A	109.5
N11—C42—H42B	109.3	N11—C16—H16B	109.5
C41—C42—H42B	109.3	C15—C16—H16B	109.5
H42A—C42—H42B	107.9	H16A—C16—H16B	108.0
C42—N11—C16	112.14 (14)

(II) 3,6-Bis(pyrazol-1-yl)-4-[2-(4-thiamorpholino)ethanesulfanyl]pyridazine

Crystal data

C16H19N7S2	Dx = 1.439 Mg m^−3
Mr = 373.50	Melting point: unknown K
Monoclinic, I2/a	Mo Kα radiation, λ = 0.71073 Å
a = 8.0944 (8) Å	Cell parameters from 3172 reflections
b = 13.9838 (14) Å	θ = 2.5–26.7°
c = 30.482 (3) Å	µ = 0.32 mm^−1
β = 92.292 (2)°	T = 150 K
V = 3447.5 (6) Å^3	Column, pale yellow
Z = 8	0.30 × 0.11 × 0.09 mm
F(000) = 1568

Data collection

Bruker SMART1000 CCD area detector diffractometer	2588 reflections with I > 2σ(I)
Radiation source: normal-focus sealed tube	Rint = 0.056
Graphite monochromator	θmax = 28.8°, θmin = 1.3°
ω scans	h = −10→10
13401 measured reflections	k = −18→17
4084 independent reflections	l = −40→35

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.040	Only H-atom coordinates refined
wR(F^2) = 0.119	w = 1/[σ^2(Fo^2) + (0.059P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.99	(Δ/σ)max = 0.001
4084 reflections	Δρmax = 0.35 e Å^−3
226 parameters	Δρmin = −0.31 e Å^−3
0 restraints

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.

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

	x	y	z	Uiso*/Ueq
N1	0.6358 (3)	−0.14161 (13)	0.33692 (7)	0.0269 (5)
N2	0.7077 (3)	−0.13226 (13)	0.29803 (7)	0.0254 (5)
C3	0.7233 (3)	−0.04727 (15)	0.27946 (8)	0.0207 (5)
C4	0.6715 (3)	0.04010 (15)	0.29862 (8)	0.0197 (5)
C5	0.5979 (3)	0.02917 (16)	0.33822 (8)	0.0232 (5)
H5	0.559 (3)	0.0816 (18)	0.3564 (8)	0.028*
C6	0.5845 (3)	−0.06270 (16)	0.35560 (8)	0.0220 (5)
N31	0.7959 (2)	−0.05210 (13)	0.23826 (7)	0.0215 (4)
N32	0.8760 (3)	0.02485 (13)	0.22162 (7)	0.0254 (5)
C33	0.9317 (3)	−0.00640 (17)	0.18392 (9)	0.0271 (6)
H33	0.993 (3)	0.0356 (18)	0.1638 (8)	0.032*
C34	0.8877 (3)	−0.10204 (17)	0.17580 (9)	0.0269 (6)
H34	0.912 (3)	−0.1371 (18)	0.1505 (9)	0.032*
C35	0.8023 (3)	−0.12977 (17)	0.21110 (9)	0.0251 (6)
H35	0.749 (3)	−0.1838 (19)	0.2181 (8)	0.030*
S41	0.69371 (8)	0.15170 (4)	0.27344 (2)	0.02365 (17)
C41	0.5871 (3)	0.23185 (17)	0.30996 (8)	0.0234 (6)
H41A	0.564 (3)	0.2891 (18)	0.2918 (8)	0.028*
H41B	0.484 (3)	0.2072 (18)	0.3165 (8)	0.028*
C42	0.6941 (3)	0.26188 (18)	0.34964 (9)	0.0260 (6)
H42A	0.779 (3)	0.3025 (19)	0.3383 (8)	0.031*
H42B	0.749 (3)	0.2085 (19)	0.3634 (9)	0.031*
N61	0.5115 (3)	−0.07501 (14)	0.39654 (7)	0.0264 (5)
N62	0.4272 (3)	−0.00125 (16)	0.41421 (8)	0.0402 (6)
C63	0.3784 (5)	−0.0364 (2)	0.45172 (11)	0.0508 (9)
H63	0.322 (4)	0.003 (2)	0.4695 (10)	0.061*
C64	0.4307 (4)	−0.1306 (2)	0.45905 (10)	0.0421 (8)
H64	0.410 (4)	−0.175 (2)	0.4833 (10)	0.051*
C65	0.5154 (4)	−0.15299 (19)	0.42305 (9)	0.0327 (6)
H65	0.567 (3)	−0.215 (2)	0.4148 (9)	0.039*
S11	0.49668 (9)	0.38125 (5)	0.47735 (2)	0.0350 (2)
C12	0.3863 (4)	0.3075 (2)	0.43741 (10)	0.0335 (6)
H12A	0.309 (4)	0.350 (2)	0.4197 (10)	0.040*
H12B	0.323 (4)	0.271 (2)	0.4533 (9)	0.040*
C13	0.5004 (4)	0.25285 (18)	0.40799 (10)	0.0294 (6)
H13A	0.430 (3)	0.2189 (19)	0.3888 (9)	0.035*
H13B	0.571 (3)	0.216 (2)	0.4275 (9)	0.035*
N14	0.6000 (2)	0.31666 (13)	0.38155 (7)	0.0234 (5)
C15	0.7128 (3)	0.37557 (18)	0.40930 (9)	0.0274 (6)
H15A	0.791 (3)	0.3385 (18)	0.4281 (9)	0.033*
H15B	0.778 (3)	0.4130 (19)	0.3908 (9)	0.033*
C16	0.6216 (4)	0.44340 (18)	0.43871 (9)	0.0311 (6)
H16A	0.700 (3)	0.4824 (19)	0.4557 (9)	0.037*
H16B	0.554 (3)	0.485 (2)	0.4204 (9)	0.037*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0309 (12)	0.0192 (10)	0.0309 (12)	0.0003 (8)	0.0037 (10)	0.0024 (9)
N2	0.0290 (12)	0.0168 (10)	0.0305 (13)	0.0028 (8)	0.0037 (10)	0.0015 (8)
C3	0.0199 (13)	0.0181 (11)	0.0241 (13)	−0.0007 (9)	0.0002 (10)	−0.0003 (9)
C4	0.0189 (12)	0.0150 (11)	0.0250 (14)	−0.0006 (9)	−0.0015 (10)	0.0003 (9)
C5	0.0269 (14)	0.0186 (12)	0.0238 (14)	0.0005 (10)	−0.0004 (11)	−0.0014 (10)
C6	0.0202 (13)	0.0226 (12)	0.0230 (14)	−0.0011 (10)	0.0001 (10)	0.0028 (10)
N31	0.0224 (11)	0.0163 (9)	0.0258 (12)	0.0008 (8)	0.0018 (9)	−0.0032 (8)
N32	0.0319 (12)	0.0176 (10)	0.0273 (12)	−0.0022 (8)	0.0065 (10)	−0.0008 (8)
C33	0.0313 (14)	0.0234 (12)	0.0269 (15)	0.0011 (11)	0.0051 (12)	−0.0005 (11)
C34	0.0292 (14)	0.0247 (13)	0.0266 (14)	0.0044 (11)	−0.0008 (11)	−0.0071 (11)
C35	0.0268 (14)	0.0164 (11)	0.0319 (15)	0.0009 (10)	−0.0017 (11)	−0.0052 (10)
S41	0.0346 (4)	0.0137 (3)	0.0231 (3)	0.0003 (2)	0.0066 (3)	−0.0006 (2)
C41	0.0284 (14)	0.0155 (11)	0.0268 (14)	0.0004 (10)	0.0066 (11)	−0.0005 (10)
C42	0.0259 (14)	0.0226 (13)	0.0298 (15)	−0.0007 (11)	0.0053 (12)	−0.0055 (10)
N61	0.0282 (12)	0.0245 (11)	0.0268 (12)	−0.0025 (9)	0.0031 (10)	0.0034 (9)
N62	0.0520 (16)	0.0337 (13)	0.0364 (15)	0.0066 (11)	0.0193 (12)	0.0046 (11)
C63	0.066 (2)	0.0486 (19)	0.040 (2)	0.0030 (16)	0.0261 (17)	0.0036 (14)
C64	0.052 (2)	0.0460 (18)	0.0288 (16)	−0.0103 (14)	0.0053 (14)	0.0120 (13)
C65	0.0366 (16)	0.0298 (14)	0.0313 (16)	−0.0038 (12)	−0.0032 (13)	0.0092 (12)
S11	0.0411 (4)	0.0366 (4)	0.0278 (4)	−0.0032 (3)	0.0071 (3)	−0.0093 (3)
C12	0.0348 (16)	0.0348 (15)	0.0315 (16)	−0.0067 (12)	0.0097 (13)	−0.0058 (12)
C13	0.0340 (16)	0.0247 (13)	0.0297 (16)	−0.0058 (11)	0.0034 (13)	−0.0046 (11)
N14	0.0264 (12)	0.0193 (9)	0.0247 (11)	−0.0027 (8)	0.0051 (9)	−0.0052 (8)
C15	0.0294 (15)	0.0250 (13)	0.0277 (15)	−0.0049 (11)	0.0015 (12)	−0.0054 (11)
C16	0.0405 (17)	0.0229 (13)	0.0300 (16)	−0.0027 (12)	0.0015 (13)	−0.0090 (11)

Geometric parameters (Å, º)

N1—C6	1.316 (3)	C42—H42B	0.96 (3)
N1—N2	1.348 (3)	N61—C65	1.357 (3)
N2—C3	1.325 (3)	N61—N62	1.360 (3)
C3—N31	1.410 (3)	N62—C63	1.319 (4)
C3—C4	1.424 (3)	C63—C64	1.400 (4)
C4—C5	1.376 (3)	C63—H63	0.91 (3)
C4—S41	1.751 (2)	C64—C65	1.354 (4)
C5—C6	1.396 (3)	C64—H64	0.99 (3)
C5—H5	0.98 (3)	C65—H65	0.99 (3)
C6—N61	1.412 (3)	S11—C12	1.805 (3)
N31—N32	1.365 (3)	S11—C16	1.806 (3)
N31—C35	1.368 (3)	C12—C13	1.519 (4)
N32—C33	1.325 (3)	C12—H12A	1.00 (3)
C33—C34	1.403 (3)	C12—H12B	0.88 (3)
C33—H33	0.99 (3)	C13—N14	1.465 (3)
C34—C35	1.358 (4)	C13—H13A	0.93 (3)
C34—H34	0.94 (3)	C13—H13B	0.96 (3)
C35—H35	0.90 (3)	N14—C15	1.471 (3)
S41—C41	1.821 (2)	C15—C16	1.517 (4)
C41—C42	1.518 (4)	C15—H15A	0.98 (3)
C41—H41A	0.99 (3)	C15—H15B	0.95 (3)
C41—H41B	0.93 (3)	C16—H16A	0.97 (3)
C42—N14	1.474 (3)	C16—H16B	0.96 (3)
C42—H42A	0.97 (3)
C6—N1—N2	116.99 (19)	C65—N61—C6	128.6 (2)
C3—N2—N1	120.98 (19)	N62—N61—C6	119.47 (19)
N2—C3—N31	112.83 (19)	C63—N62—N61	103.5 (2)
N2—C3—C4	124.0 (2)	N62—C63—C64	112.9 (3)
N31—C3—C4	123.1 (2)	N62—C63—H63	118 (2)
C5—C4—C3	114.2 (2)	C64—C63—H63	129 (2)
C5—C4—S41	122.61 (17)	C65—C64—C63	104.4 (3)
C3—C4—S41	123.20 (18)	C65—C64—H64	124.7 (18)
C4—C5—C6	118.6 (2)	C63—C64—H64	130.9 (17)
C4—C5—H5	125.0 (15)	C64—C65—N61	107.3 (2)
C6—C5—H5	116.3 (15)	C64—C65—H65	129.6 (16)
N1—C6—C5	125.2 (2)	N61—C65—H65	123.1 (16)
N1—C6—N61	115.5 (2)	C12—S11—C16	96.31 (13)
C5—C6—N61	119.3 (2)	C13—C12—S11	112.9 (2)
N32—N31—C35	111.79 (19)	C13—C12—H12A	111.0 (16)
N32—N31—C3	120.99 (18)	S11—C12—H12A	107.9 (17)
C35—N31—C3	127.2 (2)	C13—C12—H12B	114.5 (18)
C33—N32—N31	104.19 (19)	S11—C12—H12B	104.0 (19)
N32—C33—C34	112.0 (2)	H12A—C12—H12B	106 (2)
N32—C33—H33	122.3 (15)	N14—C13—C12	112.3 (2)
C34—C33—H33	125.6 (15)	N14—C13—H13A	107.7 (17)
C35—C34—C33	105.4 (2)	C12—C13—H13A	104.7 (17)
C35—C34—H34	129.1 (16)	N14—C13—H13B	110.1 (16)
C33—C34—H34	125.5 (16)	C12—C13—H13B	105.5 (16)
C34—C35—N31	106.6 (2)	H13A—C13—H13B	117 (2)
C34—C35—H35	133.8 (17)	C13—N14—C15	111.5 (2)
N31—C35—H35	119.5 (17)	C13—N14—C42	110.88 (19)
C4—S41—C41	102.77 (11)	C15—N14—C42	110.21 (19)
C42—C41—S41	112.82 (18)	N14—C15—C16	112.6 (2)
C42—C41—H41A	108.1 (15)	N14—C15—H15A	114.1 (16)
S41—C41—H41A	103.8 (14)	C16—C15—H15A	107.5 (15)
C42—C41—H41B	114.7 (16)	N14—C15—H15B	108.4 (16)
S41—C41—H41B	110.7 (15)	C16—C15—H15B	107.6 (16)
H41A—C41—H41B	106 (2)	H15A—C15—H15B	106 (2)
N14—C42—C41	112.1 (2)	C15—C16—S11	112.52 (18)
N14—C42—H42A	108.9 (15)	C15—C16—H16A	110.0 (16)
C41—C42—H42A	105.7 (16)	S11—C16—H16A	107.2 (16)
N14—C42—H42B	111.0 (16)	C15—C16—H16B	108.5 (16)
C41—C42—H42B	112.0 (16)	S11—C16—H16B	110.4 (16)
H42A—C42—H42B	107 (2)	H16A—C16—H16B	108 (2)
C65—N61—N62	111.9 (2)