Isomeric 3- and 4-chloro-N-[1-(1H-pyrrol-2-yl)ethyl­idene]aniline

The title isomers, namely 3-chloro-N-[1-(1H-pyrrol-2-yl)ethyl­idene]aniline, (I), and 4-chloro-N-[1-(1H-pyrrol-2-yl)ethyl­idene]aniline, (II), both C₁₂H₁₁ClN₂, differ in the position of the chlorine substitution. Both compounds have the basic imino­pyrrole structure, which shows a planar backbone with similar features. The dihedral angle formed by the planes of the pyrrole and benzene rings is 75.65 (7)° for (I) and 86.56 (8)° for (II). The H atom bound to the pyrrole N atom is positionally disordered and partial protonation occurs at the imino N atom in (I), while this phenomenon is absent from the structure of (II). Packing inter­actions for both compounds include inter­molecular N—H...N hydrogen bonds and C—H...π inter­actions, forming centrosymmetric dimers for both (I) and (II).

S1. Comment

Nitrogen-based ligands have recently attacted attention owing to their advantageous flexible complexation of transition metals. Late transition metal catalysts incorporating bis(imino)pyridine, a typical example of a nitrogen-based unit, have been investigated due to their antioxidant properties and outstanding activities for olefin polymerization (Britovsek et al., 2003). A recent exploration of iminopyridine ligand modification has promoted the synthetic application of iminopyrrolyl ligands for preparing many kinds of transition metal complexes (Mashima & Tsurugi, 2005). These complexes are primarily regarded as precatalysts in polymerization reactions. We ourselves have reported the molecular structures of some iminopyrrolyl compounds, namely N-[1-(1H-pyrrol-2-yl)ethylidene]aniline, (III) (Su, Li, Wang & Li, 2012a), 2,4,6-trimethyl-N-[1-(1H-pyrrol-2-yl)ethylidene]aniline, (IV) (Su, Li, Wang & Li, 2012b), 2,5-dimethyl-N-[1-(1H-pyrrol-2-yl)ethylidene]aniline, (V) (Su, Qin & Wang, 2012b), and 2-methyl-N-[1-(1H-pyrrol-2-yl)ethylidene]aniline, (VI) (Su, Qin & Wang, 2012a) (see Scheme 1).

As part of our ongoing studies of mono(imino)pyrrole ligands (Su et al., 2009a,b), we present here the crystal structures of the title isomeric compounds 3-chloro-N-[1-(1H-pyrrol-2-yl)ethylidene]aniline, (I) (Fig. 1), and 4-chloro-N-[1-(1H-pyrrol-2-yl)ethylidene]aniline, (II) (Fig. 2), in which the meta- or para-positions of the benzene rings are substituted by chlorine. Both compounds have the basic iminopyrrole structure, which shows a planar backbone with similar features. A brief analysis of the bond lengths and angles in these derivatives (Tables 1 and 3) indicates that the two molecules are similar, but some minor differences in corresponding bond lengths and angles are present. The N1—C4—C5—N2 torsion angles of -1.7 (3)° in (I) and 0.1 (3)° in (II) show that the pyrrole rings and the –N═C(CH₃)– groups are nearly coplanar in both cases. The C4—C5 bond lengths [1.441 (3)–1.465 (3) Å] are slightly shorter than normal values for typical Csp²—Csp² single bonds (1.476 Å; Allen et al., 1987), suggesting an extension of the pyrrole-ring electron delocalization towards the –N═C(CH₃)– substituent.

For both (I) and (II), the benzene substituents of the imino fragments adopt dihedral angles of around 80° relative to the pyrrole ring [75.65 (7) and 86.56 (8)° in (I) and (II), respectively]. This is also the case in (III) [72.37 (7) and 82.34 (8)°], (IV) [78.90 (9) and 79.96 (9)°], (V) [72.37 (8)°] and (VI) [83.63 (8) and 87.84 (8)°], in which the benzene rings are rotated about the N_imine—C_ar bond, forming dihedral angles of around 80° to the plane of the pyrrole ring defined by atoms C5/N2/C7/C8. However, the variation in the dihedral angles in this family of structures may not be related to the steric hindrance exerted by the methyl groups or Cl atoms in the different positions. For example, (III) and (IV) both contain two crystallographically independent molecules which have the same substitution on the phenyl ring. The torsion angles in the two molecules of (III) differ by 10°, whereas the molecules in (IV) have almost the same torsion angles. Similarly, in the two stuctrues presented herein, the torsion angles in (I) should be larger than in (II), owing to the greater repulsion of the Cl atom in the meta-position compared with that in the para-position, but this is not the case. Thus, the variation in the dihedral angles of these compounds may be due to packing effects instead of related to the substitution on the phenyl ring.

It has been reported (Su, Li, Wang & Li, 2012a,b; Su, Qin & Wang, 2012b; Su, Qin & Wang, 2012a) that these types of organic derivatives assemble as iminopyrrole dimers through the formation of two complementary hydrogen bonds between a pyrrole N—H group and the imine N atom belonging to the other molecule of the pair. Corresponding to this, compounds (I) and (II) both show dimerization of the iminopyrrole molecules through an R₂²(10) motif (Bernstein et al., 1995). In the structure of (I), there is an indication (residual density) that the H atom on N1 is disordered, distributed over N1 and N2. This disorder is absent from the structure of (II). A strong intermolecular hydrogen bond exists in (I) and (II) between atoms N1 and N2ⁱ [symmetry code: (i) -x + 1/2, -y + 3/2, -z + 1; Tables 2 and 4], which joins the molecules head-to-tail across crystallographic inversion centres to give dimers. Owing to the H-atom disorder, two such hydrogen bonds exist in the structure of (I), one with the H atom on N1 and the other with N2 protonated, as can be seen in Fig. 3. In addition, the H-atom disorder in (I) suggests the existence of two possible tautomers, (Ia) and (Ib) (see Scheme 2). The strong electrostatic attraction between the pyrrole N-bound H atom and the imino N atom draws the H atom away from the pyrrole N atom and nearer to the imino N atom. Under certain conditions, the H atom can transfer from the pyrrole N atom to the imino N atom. Tautomers (Ia) and (Ib), as important contributors to the overall molecular structure of (I), are both present. At the same time, the structures of (I) and (II) are stabilized by a pair of intermolecular C—H···π^i,ii interactions [symmetry code: (ii) -x + 1, -y, -z; Tables 2 and 4), thereby saturating the hydrogen-bonding capability of the aromatic π-electron clouds (Figs. 3 and 4). Pyrrole atom C1 acts as the donor and the benzene ring as acceptor. The H1A···Cg1 (Cg1 is the centroid of the C7–C12 benzene ring) distances are 2.88 and 2.80 Å, and the C—H···π angles are 132.0 and 142.0°, for (I) and (II), respectively. It has been acknowledged that these weak C—H···π interactions can have a profound effect on the conformations of organic compounds (Umezawa et al., 1999).

Related literature

For related literature, see: Allen et al. (1987); Bernstein et al. (1995); Britovsek et al. (2003); Mashima & Tsurugi (2005); Su et al. (2009a, 2009b); Su, Li, Wang & Li (2012a, 2012b); Su, Qin & Wang (2012a, 2012b); Umezawa et al. (1999).

S2. Experimental

For the synthesis of (I), 2-acetylpyrrole (0.3676 g, 3.37 mmol) and m-chloroaniline (0.8270 g, 6.74 mmol) were placed in a 50 ml flask. For the synthesis of (II), 2-acetylpyrrole (0.1975 g, 2.15 mmol) and p-chloroaniline (0.4700 g, 4.31 mmol) were placed in a 50 ml flask. A few drops of acetic acid were added in each case and the resulting mixture was subjected to microwave radiation in an 800 W oven for 3 min [for (I)] or 2 min [for (II)] on a medium heat setting. The colour of the solution of (I) changed from colourless to black and that of (II) from grey to black. The reaction was monitored by thin-layer chromatography and the crude product was purified by silica-gel column chromatography (eluant = petroleum ether/ethyl acetate, 5:1 v:v). Colourless crystals of (I) and (II) were obtained by recrystallization from ethanol–water [Solvent ratio?] [(I): yield 0.2155 g, 29.24%, m.p. 362.6–364.4 K; (II): yield 0.1436 g, 30.54%, m.p. 406.0–407.6 K]. Crystallization from ethanol–water [Solvent ratio?] gave crystals suitable for single-crystal X-ray diffraction.

The purity and composition of (I) and (II) were checked and characterized by IR spectroscopy, NMR and mass spectrometry, and elemental analysis. Data for (I): IR (KBr): ν_C═N 1668 cm^-1; ¹H NMR (400 MHz, CDCl₃, δ, p.p.m.): 7.25 (d, 2H, benzene ring aromatic H), 6.91 (t, 1H, benzene ring aromatic H), 6.83 (d, 1H, pyrrole ring aromatic H), 6.64 (d, 1H, benzene ring aromatic H), 6.55 (t, 1H, pyrrole ring aromatic H), 6.29 (d, 1H, pyrrole ring aromatic H), 2.15 [s, 3H, –N═ C(CH₃)-]; MS (EI): m/z 217 (M⁺); analysis, calculated for C₁₂H₁₁ClN₂: C 65.91, H 5.07, N 12.81%; found: C 65.32, H 4.48, N 12.50%.

Data for (II): IR (KBr): ν_C═N 1668 cm^{-1; 1}H (400 MHz, CDCl₃, δ, p.p.m.): 7.26 (t, 2H, benzene ring aromatic H), 6.85 (d, 1H, pyrrole ring aromatic H), 6.74 (t, 2H, benzene ring aromatic H), 6.67 (t, 1H, pyrrole ring aromatic H), 6.26 (d, 1H, pyrrole ring aromatic H), 2.11 [s, 3H, –N═C(CH₃)-]; MS (EI): m/z 217 (M⁺); analysis, calculated for C₁₂H₁₁ClN₂: C 65.91, H 5.07, N 12.81%; found: C 66.59, H 4.32, N 12.87%.

S3. Refinement

For both compounds, the methyl groups were treated as disordered about the C5—C6 bond. The C—H distances were constrained to 0.96 Å, with U_iso(H) = 1.5U_eq(C), and the relative occupancies were refined freely. N-bound H atoms were located in difference electron-density maps and refined isotropically with the help of distance restraints [target value 0.86 (1) Å]. All remaining H atoms were placed in idealized positions (C—H = 0.93 Å) and allowed to ride on their respective parent atom, with U_iso(H) = 1.2U_eq(C). In (I), inspection of the contoured representation of the difference electron density indicated that the pyrrole N-bound H atom was disordered. It was modelled over two sets of positions, with a refined major-component occupancy of 0.85 (3). For (II), one reflection, which was clearly outlier data and failed to meet processing requirements, was omitted.

Computing details

For both compounds, data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

	Fig. 1. The molecular structure of (I), showing the atom-numbering scheme. Molecule A shows the structure with the H atom on N1 and molecule B shows that with the H atom on N2. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The molecular structure of (II), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 3. Views of the N—H···N and C—H···π interactions (dotted lines) in the crystal structures of (I) and (II). H atoms not participating in hydrogen bonding have been omitted for clarity. The largest spheres indicate Cg1, the centroid of the C7–C12 ring. (a) The structure of (I) with the H atom on N1, (b) the structure of (I) with the H atom on N2 and (c) the structure of (II). [Symmetry codes: (i) -x + 1/2, -y + 3/2, -z + 1; (ii) -x + 1, -y, -z.]

(I) 3-Chloro-N-[1-(1H-pyrrol-2-yl)ethylidene]aniline

Crystal data

C12H11ClN2	F(000) = 912
Mr = 218.68	Dx = 1.283 Mg m^−3
Monoclinic, C2/c	Melting point: 362.6 K
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 23.722 (15) Å	θ = 3.2–26.2°
b = 5.720 (4) Å	µ = 0.31 mm^−1
c = 16.868 (11) Å	T = 296 K
β = 98.404 (10)°	Block, colourless
V = 2264 (3) Å^3	0.37 × 0.29 × 0.20 mm
Z = 8

Data collection

Bruker APEXII CCD area-detector diffractometer	2235 independent reflections
Radiation source: fine-focus sealed tube	1611 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.044
ϕ and ω scans	θmax = 26.2°, θmin = 3.2°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −25→29
Tmin = 0.896, Tmax = 0.941	k = −7→6
5682 measured reflections	l = −20→20

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.042	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.120	w = 1/[σ^2(Fo^2) + (0.055P)^2 + 0.750P] where P = (Fo^2 + 2Fc^2)/3
S = 1.01	(Δ/σ)max < 0.001
2235 reflections	Δρmax = 0.19 e Å^−3
145 parameters	Δρmin = −0.19 e Å^−3
2 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0035 (8)

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.

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	Occ. (<1)
Cl1	0.47791 (2)	0.67469 (13)	0.35356 (4)	0.0865 (3)
N1	0.16869 (6)	0.7513 (3)	0.40993 (10)	0.0563 (4)
H1	0.1925 (9)	0.813 (4)	0.4468 (11)	0.068*	0.85 (3)
N2	0.27532 (6)	0.5367 (3)	0.41718 (10)	0.0549 (4)
H2A	0.270 (6)	0.61 (2)	0.460 (5)	0.066*	0.15 (3)
C1	0.11410 (8)	0.8304 (4)	0.38903 (13)	0.0688 (6)
H1A	0.0976	0.9554	0.4124	0.083*
C2	0.08828 (9)	0.6952 (5)	0.32843 (14)	0.0842 (7)
H2	0.0511	0.7117	0.3027	0.101*
C3	0.12771 (9)	0.5252 (4)	0.31127 (13)	0.0782 (7)
H3	0.1212	0.4086	0.2726	0.094*
C4	0.17798 (7)	0.5635 (3)	0.36246 (10)	0.0542 (5)
C5	0.23386 (7)	0.4508 (3)	0.36766 (10)	0.0509 (4)
C6	0.23902 (10)	0.2473 (4)	0.31262 (13)	0.0696 (6)
H6A	0.2657	0.2850	0.2769	0.104*	0.53 (3)
H6B	0.2025	0.2146	0.2820	0.104*	0.53 (3)
H6C	0.2522	0.1123	0.3438	0.104*	0.53 (3)
H6E	0.2145	0.1230	0.3249	0.104*	0.47 (3)
H6D	0.2778	0.1933	0.3198	0.104*	0.47 (3)
H6F	0.2281	0.2957	0.2580	0.104*	0.47 (3)
C7	0.33193 (7)	0.4440 (3)	0.42002 (10)	0.0518 (4)
C8	0.34820 (9)	0.2336 (4)	0.45754 (13)	0.0674 (6)
H8	0.3215	0.1411	0.4781	0.081*
C9	0.40503 (10)	0.1618 (4)	0.46411 (14)	0.0763 (6)
H9	0.4160	0.0225	0.4904	0.092*
C10	0.44537 (9)	0.2937 (4)	0.43234 (13)	0.0708 (6)
H10	0.4830	0.2438	0.4366	0.085*
C11	0.42814 (8)	0.5022 (4)	0.39403 (11)	0.0591 (5)
C12	0.37214 (7)	0.5807 (3)	0.38867 (10)	0.0535 (4)
H12	0.3616	0.7232	0.3644	0.064*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0497 (3)	0.1167 (6)	0.0964 (5)	0.0098 (3)	0.0217 (3)	0.0212 (4)
N1	0.0421 (8)	0.0657 (10)	0.0602 (10)	0.0005 (7)	0.0050 (6)	−0.0060 (8)
N2	0.0445 (8)	0.0640 (10)	0.0571 (9)	0.0037 (7)	0.0103 (7)	−0.0098 (8)
C1	0.0469 (10)	0.0857 (15)	0.0734 (13)	0.0100 (10)	0.0074 (9)	−0.0022 (11)
C2	0.0447 (11)	0.130 (2)	0.0739 (14)	0.0097 (12)	−0.0030 (9)	−0.0111 (14)
C3	0.0555 (12)	0.1145 (19)	0.0629 (12)	−0.0043 (12)	0.0025 (9)	−0.0250 (13)
C4	0.0464 (9)	0.0675 (12)	0.0500 (10)	−0.0048 (8)	0.0118 (7)	−0.0036 (9)
C5	0.0531 (10)	0.0573 (11)	0.0443 (9)	−0.0041 (8)	0.0133 (7)	−0.0005 (8)
C6	0.0707 (13)	0.0722 (13)	0.0669 (13)	−0.0021 (11)	0.0132 (10)	−0.0157 (11)
C7	0.0487 (9)	0.0604 (11)	0.0464 (9)	0.0071 (8)	0.0073 (7)	−0.0072 (8)
C8	0.0690 (13)	0.0635 (12)	0.0706 (13)	0.0043 (10)	0.0131 (10)	0.0051 (10)
C9	0.0773 (15)	0.0624 (13)	0.0865 (16)	0.0187 (11)	0.0023 (12)	0.0107 (11)
C10	0.0566 (12)	0.0766 (15)	0.0772 (14)	0.0240 (10)	0.0026 (10)	−0.0008 (11)
C11	0.0480 (10)	0.0749 (13)	0.0548 (10)	0.0107 (9)	0.0089 (8)	−0.0019 (10)
C12	0.0472 (9)	0.0627 (11)	0.0499 (10)	0.0107 (8)	0.0051 (7)	0.0012 (8)

Geometric parameters (Å, º)

Cl1—C11	1.752 (2)	C6—H6B	0.9600
N1—C1	1.369 (3)	C6—H6C	0.9600
N1—C4	1.377 (3)	C6—H6E	0.9600
N1—H1	0.852 (10)	C6—H6D	0.9600
N2—C5	1.291 (2)	C6—H6F	0.9600
N2—C7	1.438 (2)	C7—C8	1.388 (3)
N2—H2A	0.861 (10)	C7—C12	1.396 (3)
C1—C2	1.355 (3)	C8—C9	1.398 (3)
C1—H1A	0.9300	C8—H8	0.9300
C2—C3	1.408 (3)	C9—C10	1.386 (3)
C2—H2	0.9300	C9—H9	0.9300
C3—C4	1.384 (3)	C10—C11	1.390 (3)
C3—H3	0.9300	C10—H10	0.9300
C4—C5	1.465 (3)	C11—C12	1.392 (2)
C5—C6	1.505 (3)	C12—H12	0.9300
C6—H6A	0.9600
C1—N1—C4	109.51 (17)	H6C—C6—H6E	56.3
C1—N1—H1	123.5 (17)	C5—C6—H6D	109.5
C4—N1—H1	127.0 (17)	H6A—C6—H6D	56.3
C5—N2—C7	120.04 (16)	H6B—C6—H6D	141.1
C5—N2—H2A	122 (9)	H6C—C6—H6D	56.3
C7—N2—H2A	114 (9)	H6E—C6—H6D	109.5
C2—C1—N1	108.18 (19)	C5—C6—H6F	109.5
C2—C1—H1A	125.9	H6A—C6—H6F	56.3
N1—C1—H1A	125.9	H6B—C6—H6F	56.3
C1—C2—C3	107.98 (19)	H6C—C6—H6F	141.1
C1—C2—H2	126.0	H6E—C6—H6F	109.5
C3—C2—H2	126.0	H6D—C6—H6F	109.5
C4—C3—C2	107.5 (2)	C8—C7—C12	119.91 (17)
C4—C3—H3	126.3	C8—C7—N2	122.08 (17)
C2—C3—H3	126.3	C12—C7—N2	117.86 (17)
N1—C4—C3	106.84 (17)	C7—C8—C9	119.4 (2)
N1—C4—C5	121.92 (15)	C7—C8—H8	120.3
C3—C4—C5	131.12 (19)	C9—C8—H8	120.3
N2—C5—C4	117.94 (17)	C10—C9—C8	121.4 (2)
N2—C5—C6	124.79 (17)	C10—C9—H9	119.3
C4—C5—C6	117.24 (16)	C8—C9—H9	119.3
C5—C6—H6A	109.5	C9—C10—C11	118.30 (19)
C5—C6—H6B	109.5	C9—C10—H10	120.8
H6A—C6—H6B	109.5	C11—C10—H10	120.8
C5—C6—H6C	109.5	C10—C11—C12	121.34 (19)
H6A—C6—H6C	109.5	C10—C11—Cl1	119.70 (15)
H6B—C6—H6C	109.5	C12—C11—Cl1	118.94 (16)
C5—C6—H6E	109.5	C11—C12—C7	119.53 (18)
H6A—C6—H6E	141.1	C11—C12—H12	120.2
H6B—C6—H6E	56.3	C7—C12—H12	120.2
C4—N1—C1—C2	−0.1 (3)	C5—N2—C7—C8	−76.9 (2)
N1—C1—C2—C3	0.5 (3)	C5—N2—C7—C12	107.7 (2)
C1—C2—C3—C4	−0.6 (3)	C12—C7—C8—C9	0.5 (3)
C1—N1—C4—C3	−0.3 (2)	N2—C7—C8—C9	−174.77 (19)
C1—N1—C4—C5	176.12 (17)	C7—C8—C9—C10	−1.5 (3)
C2—C3—C4—N1	0.6 (3)	C8—C9—C10—C11	0.6 (3)
C2—C3—C4—C5	−175.4 (2)	C9—C10—C11—C12	1.2 (3)
C7—N2—C5—C4	−175.15 (15)	C9—C10—C11—Cl1	179.66 (17)
C7—N2—C5—C6	2.8 (3)	C10—C11—C12—C7	−2.1 (3)
N1—C4—C5—N2	−1.7 (3)	Cl1—C11—C12—C7	179.41 (13)
C3—C4—C5—N2	173.7 (2)	C8—C7—C12—C11	1.2 (3)
N1—C4—C5—C6	−179.83 (18)	N2—C7—C12—C11	176.72 (16)
C3—C4—C5—C6	−4.4 (3)

Hydrogen-bond geometry (Å, º)

Cg1 is the centroid of the C7–C12 ring.

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N2^i	0.85 (1)	2.47 (1)	3.257 (3)	155 (2)
N2—H2A···N1^i	0.86 (1)	2.58 (9)	3.257 (3)	136 (11)
C1—H1A···Cg1^i	0.93	2.88	3.568 (2)	132

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

(II) 4-Chloro-N-[1-(1H-pyrrol-2-yl)ethylidene]aniline

Crystal data

C12H11ClN2	F(000) = 456
Mr = 218.68	Dx = 1.293 Mg m^−3
Monoclinic, P21/c	Melting point: 406.0 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 13.323 (3) Å	θ = 3.2–26.4°
b = 9.802 (2) Å	µ = 0.31 mm^−1
c = 9.107 (2) Å	T = 296 K
β = 109.212 (4)°	Block, colourless
V = 1123.1 (4) Å^3	0.37 × 0.26 × 0.15 mm
Z = 4

Data collection

Bruker APEXII CCD area-detector diffractometer	2273 independent reflections
Radiation source: fine-focus sealed tube	1701 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
ϕ and ω scans	θmax = 26.4°, θmin = 3.2°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −16→16
Tmin = 0.895, Tmax = 0.954	k = −12→12
6016 measured reflections	l = −8→11

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.047	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.119	w = 1/[σ^2(Fo^2) + (0.038P)^2 + 0.5P] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max < 0.001
2273 reflections	Δρmax = 0.31 e Å^−3
141 parameters	Δρmin = −0.38 e Å^−3
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.084 (5)

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.

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	Occ. (<1)
Cl1	0.00330 (5)	0.16504 (11)	0.14277 (11)	0.1178 (4)
N1	0.65655 (12)	0.04155 (17)	0.16365 (18)	0.0513 (4)
H1	0.6113 (13)	0.007 (2)	0.0813 (16)	0.062*
N2	0.44650 (12)	0.08102 (17)	0.16294 (18)	0.0541 (4)
C1	0.76260 (15)	0.0441 (2)	0.1946 (2)	0.0616 (6)
H1A	0.7987	0.0081	0.1318	0.074*
C2	0.80796 (17)	0.1080 (2)	0.3330 (3)	0.0686 (6)
H2	0.8802	0.1235	0.3819	0.082*
C3	0.72636 (17)	0.1458 (2)	0.3875 (3)	0.0645 (6)
H3	0.7343	0.1915	0.4802	0.077*
C4	0.63166 (15)	0.10419 (19)	0.2812 (2)	0.0495 (5)
C5	0.52395 (15)	0.12363 (19)	0.2789 (2)	0.0501 (5)
C6	0.50966 (19)	0.1964 (3)	0.4156 (3)	0.0790 (7)
H6A	0.4391	0.2335	0.3868	0.118*	0.42 (3)
H6B	0.5607	0.2689	0.4476	0.118*	0.42 (3)
H6C	0.5200	0.1332	0.4999	0.118*	0.42 (3)
H6D	0.5741	0.1903	0.5027	0.118*	0.58 (3)
H6E	0.4526	0.1548	0.4419	0.118*	0.58 (3)
H6F	0.4932	0.2905	0.3896	0.118*	0.58 (3)
C7	0.34104 (15)	0.1035 (2)	0.1626 (2)	0.0530 (5)
C8	0.28700 (18)	0.2205 (2)	0.0996 (3)	0.0684 (6)
H8	0.3210	0.2877	0.0614	0.082*
C9	0.18295 (19)	0.2391 (3)	0.0924 (3)	0.0745 (7)
H9	0.1470	0.3186	0.0497	0.089*
C10	0.13327 (17)	0.1407 (3)	0.1481 (3)	0.0713 (6)
C11	0.18439 (19)	0.0230 (3)	0.2082 (3)	0.0798 (7)
H11	0.1495	−0.0443	0.2448	0.096*
C12	0.28855 (17)	0.0040 (3)	0.2146 (3)	0.0684 (6)
H12	0.3234	−0.0768	0.2546	0.082*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0542 (4)	0.1710 (9)	0.1335 (7)	0.0110 (4)	0.0378 (4)	0.0114 (6)
N1	0.0463 (9)	0.0600 (10)	0.0466 (9)	−0.0006 (7)	0.0139 (7)	−0.0058 (8)
N2	0.0518 (9)	0.0644 (11)	0.0497 (9)	−0.0025 (8)	0.0214 (8)	−0.0073 (8)
C1	0.0484 (11)	0.0752 (14)	0.0618 (12)	0.0013 (10)	0.0189 (9)	−0.0040 (11)
C2	0.0505 (12)	0.0806 (15)	0.0671 (14)	−0.0072 (11)	0.0090 (10)	−0.0075 (12)
C3	0.0634 (13)	0.0696 (14)	0.0548 (12)	−0.0042 (11)	0.0118 (10)	−0.0127 (10)
C4	0.0547 (11)	0.0478 (10)	0.0452 (10)	−0.0022 (8)	0.0154 (8)	−0.0023 (8)
C5	0.0572 (11)	0.0487 (10)	0.0473 (10)	0.0004 (9)	0.0208 (9)	−0.0025 (9)
C6	0.0702 (14)	0.1024 (19)	0.0658 (14)	0.0004 (13)	0.0243 (12)	−0.0341 (14)
C7	0.0528 (11)	0.0625 (12)	0.0476 (10)	−0.0036 (9)	0.0218 (9)	−0.0096 (9)
C8	0.0677 (14)	0.0594 (13)	0.0880 (16)	0.0000 (11)	0.0390 (12)	0.0010 (12)
C9	0.0672 (14)	0.0703 (15)	0.0902 (17)	0.0105 (12)	0.0316 (13)	−0.0007 (13)
C10	0.0495 (11)	0.0986 (19)	0.0679 (14)	0.0034 (12)	0.0223 (10)	−0.0013 (13)
C11	0.0595 (13)	0.105 (2)	0.0778 (16)	−0.0125 (13)	0.0269 (12)	0.0185 (15)
C12	0.0610 (13)	0.0755 (15)	0.0693 (14)	0.0012 (11)	0.0222 (11)	0.0147 (12)

Geometric parameters (Å, º)

Cl1—C10	1.733 (2)	C6—H6B	0.9600
N1—C1	1.347 (2)	C6—H6C	0.9600
N1—C4	1.366 (2)	C6—H6D	0.9600
N1—H1	0.864 (9)	C6—H6E	0.9600
N2—C5	1.279 (2)	C6—H6F	0.9600
N2—C7	1.421 (2)	C7—C12	1.372 (3)
C1—C2	1.358 (3)	C7—C8	1.375 (3)
C1—H1A	0.9300	C8—C9	1.378 (3)
C2—C3	1.386 (3)	C8—H8	0.9300
C2—H2	0.9300	C9—C10	1.359 (3)
C3—C4	1.376 (3)	C9—H9	0.9300
C3—H3	0.9300	C10—C11	1.360 (4)
C4—C5	1.441 (3)	C11—C12	1.382 (3)
C5—C6	1.500 (3)	C11—H11	0.9300
C6—H6A	0.9600	C12—H12	0.9300
C1—N1—C4	109.63 (16)	C5—C6—H6E	109.5
C1—N1—H1	125.1 (14)	H6A—C6—H6E	56.3
C4—N1—H1	125.3 (14)	H6B—C6—H6E	141.1
C5—N2—C7	118.67 (15)	H6C—C6—H6E	56.3
N1—C1—C2	108.60 (19)	H6D—C6—H6E	109.5
N1—C1—H1A	125.7	C5—C6—H6F	109.5
C2—C1—H1A	125.7	H6A—C6—H6F	56.3
C1—C2—C3	107.09 (19)	H6B—C6—H6F	56.3
C1—C2—H2	126.5	H6C—C6—H6F	141.1
C3—C2—H2	126.5	H6D—C6—H6F	109.5
C4—C3—C2	108.32 (19)	H6E—C6—H6F	109.5
C4—C3—H3	125.8	C12—C7—C8	118.71 (19)
C2—C3—H3	125.8	C12—C7—N2	120.34 (19)
N1—C4—C3	106.37 (17)	C8—C7—N2	120.78 (18)
N1—C4—C5	123.05 (16)	C7—C8—C9	120.7 (2)
C3—C4—C5	130.51 (18)	C7—C8—H8	119.6
N2—C5—C4	119.87 (16)	C9—C8—H8	119.6
N2—C5—C6	123.49 (18)	C10—C9—C8	119.6 (2)
C4—C5—C6	116.64 (17)	C10—C9—H9	120.2
C5—C6—H6A	109.5	C8—C9—H9	120.2
C5—C6—H6B	109.5	C9—C10—C11	120.8 (2)
H6A—C6—H6B	109.5	C9—C10—Cl1	119.8 (2)
C5—C6—H6C	109.5	C11—C10—Cl1	119.4 (2)
H6A—C6—H6C	109.5	C10—C11—C12	119.6 (2)
H6B—C6—H6C	109.5	C10—C11—H11	120.2
C5—C6—H6D	109.5	C12—C11—H11	120.2
H6A—C6—H6D	141.1	C7—C12—C11	120.6 (2)
H6B—C6—H6D	56.3	C7—C12—H12	119.7
H6C—C6—H6D	56.3	C11—C12—H12	119.7
C4—N1—C1—C2	0.2 (2)	C5—N2—C7—C12	−95.2 (2)
N1—C1—C2—C3	−0.1 (3)	C5—N2—C7—C8	89.7 (2)
C1—C2—C3—C4	0.0 (3)	C12—C7—C8—C9	1.6 (3)
C1—N1—C4—C3	−0.2 (2)	N2—C7—C8—C9	176.8 (2)
C1—N1—C4—C5	177.04 (18)	C7—C8—C9—C10	−0.1 (4)
C2—C3—C4—N1	0.1 (2)	C8—C9—C10—C11	−1.2 (4)
C2—C3—C4—C5	−176.9 (2)	C8—C9—C10—Cl1	178.79 (19)
C7—N2—C5—C4	−179.02 (17)	C9—C10—C11—C12	0.9 (4)
C7—N2—C5—C6	0.1 (3)	Cl1—C10—C11—C12	−179.13 (19)
N1—C4—C5—N2	0.1 (3)	C8—C7—C12—C11	−2.0 (3)
C3—C4—C5—N2	176.7 (2)	N2—C7—C12—C11	−177.2 (2)
N1—C4—C5—C6	−179.0 (2)	C10—C11—C12—C7	0.7 (4)
C3—C4—C5—C6	−2.5 (3)

Hydrogen-bond geometry (Å, º)

Cg1 is the centroid of the C7–C12 ring.

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N2^i	0.86 (1)	2.27 (1)	3.080 (2)	156 (2)
C1—H1A···Cg1^i	0.93	2.80	3.574 (1)	142

Symmetry code: (i) −x+1, −y, −z.