1-Methyl-2,3-dihydro-1H-benzimidazole-2-selone.

The title compound C(8)H(8)N(2)Se, is the product of the reaction of 2-chloro-1-methyl-benzimidazole with sodium hydro-selenide. The mol-ecule is almost planar (r.m.s. deviation = 0.041 Å) owing to the presence of the long chain of conjugated bonds (Se=C-NMe-C=C-C=C-C=C-NH). The C=Se bond length [1.838 (2) Å] corresponds well to those found in the close analogs and indicates its pronounced double-bond character. In the crystal, mol-ecules form helicoidal chains along the b axis by means of N-H⋯Se hydrogen bonds.

Related literature

For selones as potential anti­thyroid drugs, see: Taurog et al. (1994 ▶); Roy & Mugesh (2005 ▶, 2006 ▶); Roy et al. (2007 ▶, 2011 ▶). For related compounds, see: Guziec & Guziec (1994 ▶); Husebye et al. (1997 ▶); Aydin et al. (1999 ▶); Akkurt et al. (2004 ▶, 2011 ▶); Landry et al. (2006 ▶); Nakanishi et al. (2008 ▶); Mammadova et al. (2011 ▶). For hypervalent adducts of selones with dihalogens and inter­halogens, see: Aragoni et al. (2001 ▶); Boyle & Godfrey (2001 ▶); Roy et al. (2011 ▶).

Experimental

Crystal data

C8H8N2Se

M = 211.12

Monoclinic,

a = 9.9434 (13) Å

b = 5.8472 (8) Å

c = 13.6387 (18) Å

β = 95.360 (2)°

V = 789.50 (18) Å3

Z = 4

Mo Kα radiation

μ = 4.69 mm−1

T = 100 K

0.24 × 0.20 × 0.20 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ▶) T min = 0.399, T max = 0.454

9470 measured reflections

2304 independent reflections

1941 reflections with I > 2σ(I)

R int = 0.030

Refinement

R[F 2 > 2σ(F 2)] = 0.027

wR(F 2) = 0.068

S = 1.00

2304 reflections

101 parameters

H-atom parameters constrained

Δρmax = 1.10 e Å−3

Δρmin = −0.28 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT-Plus (Bruker, 2001 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812013700/rk2347sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812013700/rk2347Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812013700/rk2347Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C8H8N2Se	F(000) = 416
Mr = 211.12	Dx = 1.776 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3916 reflections
a = 9.9434 (13) Å	θ = 2.4–32.5°
b = 5.8472 (8) Å	µ = 4.69 mm−1
c = 13.6387 (18) Å	T = 100 K
β = 95.360 (2)°	Prism, yellow
V = 789.50 (18) Å3	0.24 × 0.20 × 0.20 mm
Z = 4

Bruker APEXII CCD diffractometer	2304 independent reflections
Radiation source: fine-focus sealed tube	1941 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
φ– and ω–scans	θmax = 30.0°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −13→13
Tmin = 0.399, Tmax = 0.454	k = −8→8
9470 measured reflections	l = −19→19

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.027	Hydrogen site location: difference Fourier map
wR(F2) = 0.068	H-atom parameters constrained
S = 1.00	w = 1/[σ2(Fo2) + (0.0345P)2 + 0.745P] where P = (Fo2 + 2Fc2)/3
2304 reflections	(Δ/σ)max = 0.001
101 parameters	Δρmax = 1.10 e Å−3
0 restraints	Δρmin = −0.28 e Å−3

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

	x	y	z	Uiso*/Ueq
Se1	0.26128 (2)	1.12016 (4)	0.878637 (16)	0.02213 (7)
N1	0.47551 (17)	0.8571 (3)	0.80856 (13)	0.0200 (3)
C2	0.3951 (2)	1.0457 (4)	0.79997 (16)	0.0203 (4)
N3	0.43002 (18)	1.1660 (3)	0.72130 (13)	0.0209 (3)
H3N	0.3892	1.2987	0.7005	0.025*
C3A	0.5294 (2)	1.0505 (4)	0.67611 (16)	0.0206 (4)
C4	0.5950 (2)	1.0978 (4)	0.59324 (16)	0.0224 (4)
H4	0.5785	1.2350	0.5568	0.027*
C5	0.6860 (2)	0.9352 (4)	0.56600 (17)	0.0242 (4)
H5	0.7320	0.9611	0.5090	0.029*
C6	0.7122 (2)	0.7339 (4)	0.62006 (16)	0.0240 (4)
H6	0.7745	0.6260	0.5986	0.029*
C7	0.6488 (2)	0.6890 (4)	0.70443 (16)	0.0220 (4)
H7	0.6674	0.5539	0.7419	0.026*
C7A	0.5571 (2)	0.8506 (3)	0.73148 (15)	0.0200 (4)
C8	0.4688 (2)	0.6817 (4)	0.88271 (17)	0.0255 (4)
H8A	0.4578	0.7533	0.9464	0.038*
H8B	0.5524	0.5919	0.8876	0.038*
H8C	0.3918	0.5810	0.8644	0.038*

	U11	U22	U33	U12	U13	U23
Se1	0.02158 (11)	0.02058 (11)	0.02486 (11)	−0.00119 (8)	0.00548 (7)	−0.00250 (8)
N1	0.0202 (8)	0.0177 (8)	0.0225 (8)	−0.0010 (6)	0.0030 (6)	0.0026 (6)
C2	0.0191 (9)	0.0196 (9)	0.0219 (9)	−0.0018 (7)	0.0011 (7)	−0.0011 (7)
N3	0.0219 (8)	0.0174 (8)	0.0236 (8)	0.0020 (6)	0.0037 (6)	0.0018 (6)
C3A	0.0195 (9)	0.0184 (9)	0.0236 (10)	−0.0006 (7)	0.0007 (7)	0.0000 (7)
C4	0.0227 (9)	0.0221 (10)	0.0222 (9)	−0.0013 (8)	0.0017 (7)	0.0027 (8)
C5	0.0231 (10)	0.0272 (11)	0.0227 (10)	−0.0019 (8)	0.0037 (8)	−0.0019 (8)
C6	0.0204 (10)	0.0242 (10)	0.0274 (11)	0.0021 (8)	0.0029 (8)	−0.0023 (8)
C7	0.0200 (9)	0.0192 (9)	0.0263 (10)	0.0007 (7)	0.0005 (8)	−0.0008 (8)
C7A	0.0184 (9)	0.0199 (9)	0.0216 (9)	−0.0015 (7)	0.0009 (7)	−0.0005 (7)
C8	0.0258 (10)	0.0237 (10)	0.0275 (11)	0.0005 (8)	0.0058 (8)	0.0063 (8)

Se1—C2	1.838 (2)	C4—H4	0.9500
N1—C2	1.361 (3)	C5—C6	1.400 (3)
N1—C7A	1.387 (3)	C5—H5	0.9500
N1—C8	1.446 (3)	C6—C7	1.388 (3)
C2—N3	1.355 (3)	C6—H6	0.9500
N3—C3A	1.388 (3)	C7—C7A	1.387 (3)
N3—H3N	0.9090	C7—H7	0.9500
C3A—C4	1.385 (3)	C8—H8A	0.9800
C3A—C7A	1.405 (3)	C8—H8B	0.9800
C4—C5	1.387 (3)	C8—H8C	0.9800
C2—N1—C7A	109.74 (17)	C6—C5—H5	119.0
C2—N1—C8	124.74 (18)	C7—C6—C5	121.3 (2)
C7A—N1—C8	125.35 (18)	C7—C6—H6	119.4
N3—C2—N1	107.24 (18)	C5—C6—H6	119.4
N3—C2—Se1	126.35 (16)	C7A—C7—C6	116.9 (2)
N1—C2—Se1	126.40 (16)	C7A—C7—H7	121.5
C2—N3—C3A	110.20 (18)	C6—C7—H7	121.5
C2—N3—H3N	123.4	C7—C7A—N1	131.8 (2)
C3A—N3—H3N	126.3	C7—C7A—C3A	121.6 (2)
C4—C3A—N3	132.4 (2)	N1—C7A—C3A	106.60 (18)
C4—C3A—C7A	121.4 (2)	N1—C8—H8A	109.5
N3—C3A—C7A	106.12 (18)	N1—C8—H8B	109.5
C3A—C4—C5	116.8 (2)	H8A—C8—H8B	109.5
C3A—C4—H4	121.6	N1—C8—H8C	109.5
C5—C4—H4	121.6	H8A—C8—H8C	109.5
C4—C5—C6	121.9 (2)	H8B—C8—H8C	109.5
C4—C5—H5	119.0
C7A—N1—C2—N3	−3.4 (2)	C5—C6—C7—C7A	1.1 (3)
C8—N1—C2—N3	−178.94 (19)	C6—C7—C7A—N1	178.4 (2)
C7A—N1—C2—Se1	175.35 (15)	C6—C7—C7A—C3A	0.0 (3)
C8—N1—C2—Se1	−0.2 (3)	C2—N1—C7A—C7	−175.6 (2)
N1—C2—N3—C3A	2.5 (2)	C8—N1—C7A—C7	−0.1 (4)
Se1—C2—N3—C3A	−176.20 (15)	C2—N1—C7A—C3A	2.9 (2)
C2—N3—C3A—C4	178.0 (2)	C8—N1—C7A—C3A	178.45 (19)
C2—N3—C3A—C7A	−0.7 (2)	C4—C3A—C7A—C7	−1.5 (3)
N3—C3A—C4—C5	−176.7 (2)	N3—C3A—C7A—C7	177.40 (19)
C7A—C3A—C4—C5	1.9 (3)	C4—C3A—C7A—N1	179.74 (19)
C3A—C4—C5—C6	−0.8 (3)	N3—C3A—C7A—N1	−1.3 (2)
C4—C5—C6—C7	−0.7 (3)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3N···Se1i	0.91	2.58	3.471 (2)	168

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3N⋯Se1i	0.91	2.58	3.471 (2)	168

Symmetry code: (i) .