β-Polymorph of phenazepam: a powder study.

THE TITLE COMPOUND [SYSTEMATIC NAME: 7-bromo-5-(2-chloro-phen-yl)-1H-1,4-benzodiazepin-2(3H)-one] (β-polymorph), C(15)H(10)BrClN(2)O, has been obtained via cryomodification of the known α-polymorph of phenazepam [Karapetyan et al. (1979 ▶). Bioorg. Khim.5, 1684-1690]. In both polymorphs, the mol-ecules, which differ only in the dihedral angles between the aromatic rings [75.4 (2)° and 86.2 (3)° in the α- and β-polymorphs, respectively], are linked into centrosymmetric dimers via N-H⋯O hydrogen bonds. In the crystal structure of the β-polymorph, weak inter-molecular C-H⋯O hydrogen bonds further link these dimers into layers parallel to bc plane.

Related literature

For details of the synthesis via cryomodification, see: Sergeev & Komarov (2006 ▶). For the crystal structure of the α-polymorph of phenazepam, see: Karapetyan et al. (1979 ▶). For details of the indexing algorithm, see: Werner et al. (1985 ▶). The methodology of the refinement (including applied restraints) has been described in detail by Ryabova et al. (2005 ▶). For the March–Dollase orientation correction, see: Dollase (1986 ▶) and for the split-type pseudo-Voigt profile, see: Toraya (1986 ▶).

Experimental

Crystal data

C15H10BrClN2O

M = 349.61

Monoclinic,

a = 14.8006 (19) Å

b = 11.6756 (14) Å

c = 8.4769 (9) Å

β = 93.679 (17)°

V = 1461.8 (3) Å3

Z = 4

Cu Kα1 radiation, λ = 1.54059 Å

μ = 5.49 mm−1

T = 295 K

Flat sheet, 15 × 1 mm

Data collection

Guinier camera G670 diffractometer

Specimen mounting: thin layer in the specimen holder of the camera

Data collection mode: transmission

Scan method: continuous

2θmin = 5.00°, 2θmax = 80.00°, 2θstep = 0.01°

Refinement

R p = 0.013

R wp = 0.017

R exp = 0.012

R Bragg = 0.059

χ2 = 2.250

7501 data points

128 parameters

64 restraints

H-atom parameters not refined

Data collection: G670 Imaging Plate Guinier Camera Software (Huber, 2002 ▶); cell refinement: MRIA (Zlokazov & Chernyshev, 1992 ▶); data reduction: G670 Imaging Plate Guinier Camera Software; method used to solve structure: simulated annealing (Zhukov et al., 2001 ▶); program(s) used to refine structure: MRIA; molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: MRIA and SHELXL97 (Sheldrick, 2008 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810037402/lh5126sup1.cif

Rietveld powder data: contains datablocks I. DOI: 10.1107/S1600536810037402/lh5126Isup2.rtv

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

C15H10BrClN2O	F(000) = 696
Mr = 349.61	Dx = 1.589 Mg m−3
Monoclinic, P21/c	Cu Kα1 radiation, λ = 1.54059 Å
Hall symbol: -P 2ybc	µ = 5.49 mm−1
a = 14.8006 (19) Å	T = 295 K
b = 11.6756 (14) Å	Particle morphology: no specific habit
c = 8.4769 (9) Å	light grey
β = 93.679 (17)°	flat sheet, 15 × 1 mm
V = 1461.8 (3) Å3	Specimen preparation: Prepared at 77 K and 6.6 10-6 kPa
Z = 4

Guinier camera G670 diffractometer	Data collection mode: transmission
Radiation source: line-focus sealed tube	Scan method: continuous
Curved Germanium (111)	2θmin = 5.00°, 2θmax = 80.00°, 2θstep = 0.01°
Specimen mounting: thin layer in the specimen holder of the camera

Refinement on Inet	Profile function: split-type pseudo-Voigt (Toraya, 1986)
Least-squares matrix: full with fixed elements per cycle	128 parameters
Rp = 0.013	64 restraints
Rwp = 0.017	0 constraints
Rexp = 0.012	H-atom parameters not refined
RBragg = 0.059	Weighting scheme based on measured s.u.'s
χ2 = 2.250	(Δ/σ)max = 0.004
7501 data points	Background function: Chebyshev polynomial up to the 5th order
Excluded region(s): none	Preferred orientation correction: March-Dollase (Dollase, 1986); direction of preferred orientation 001, texture parameter r = 0.93(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.

	x	y	z	Uiso*/Ueq
Br1	0.77280 (15)	0.40430 (17)	−0.3314 (2)	0.0470 (11)*
C2	0.8173 (12)	0.4317 (13)	−0.1182 (18)	0.074 (9)*
C3	0.8911 (12)	0.3743 (12)	−0.044 (2)	0.075 (8)*
H3	0.9200	0.3154	−0.0943	0.090*
C4	0.9202 (11)	0.4080 (13)	0.109 (2)	0.063 (9)*
H4	0.9684	0.3696	0.1616	0.076*
C5	0.8784 (12)	0.4986 (15)	0.1866 (18)	0.076 (8)*
C6	0.8023 (12)	0.5539 (13)	0.110 (2)	0.076 (9)*
C7	0.7727 (11)	0.5187 (16)	−0.0430 (18)	0.071 (8)*
H7	0.7228	0.5540	−0.0945	0.085*
N8	0.9112 (9)	0.5266 (11)	0.3406 (13)	0.064 (6)*
H8	0.9247	0.4696	0.4020	0.077*
C9	0.9248 (12)	0.6346 (12)	0.406 (2)	0.072 (8)*
O10	0.9656 (7)	0.6458 (8)	0.5370 (13)	0.057 (5)*
C11	0.8837 (11)	0.7351 (13)	0.311 (2)	0.070 (8)*
H11A	0.8966	0.8060	0.3674	0.084*
H11B	0.9113	0.7396	0.2101	0.084*
N12	0.7856 (8)	0.7217 (10)	0.2827 (16)	0.062 (7)*
C13	0.7513 (11)	0.6468 (13)	0.1858 (19)	0.061 (8)*
C14	0.6501 (11)	0.6452 (14)	0.1602 (18)	0.071 (9)*
C15	0.6074 (12)	0.7367 (12)	0.077 (2)	0.074 (8)*
H15	0.6425	0.7953	0.0384	0.089*
C16	0.5134 (11)	0.7411 (11)	0.051 (2)	0.075 (8)*
H16	0.4864	0.8028	−0.0033	0.090*
C17	0.4600 (11)	0.6530 (13)	0.106 (2)	0.073 (9)*
H17	0.3976	0.6540	0.0834	0.087*
C18	0.5002 (12)	0.5633 (14)	0.1936 (17)	0.074 (9)*
H18	0.4646	0.5067	0.2356	0.089*
C19	0.5943 (12)	0.5595 (13)	0.2180 (16)	0.065 (8)*
Cl20	0.6428 (3)	0.4396 (4)	0.3145 (5)	0.054 (2)*

Br1—C2	1.910 (15)	C11—N12	1.46 (2)
C2—C7	1.39 (2)	C11—H11A	0.9704
C2—C3	1.40 (2)	C11—H11B	0.9697
C3—C4	1.40 (2)	N12—C13	1.28 (2)
C3—H3	0.9297	C13—C14	1.50 (2)
C4—C5	1.41 (2)	C14—C19	1.41 (2)
C4—H4	0.9299	C14—C15	1.41 (2)
C5—N8	1.402 (19)	C15—C16	1.40 (2)
C5—C6	1.42 (2)	C15—H15	0.9299
C6—C7	1.41 (2)	C16—C17	1.39 (2)
C6—C13	1.49 (2)	C16—H16	0.9299
C7—H7	0.9301	C17—C18	1.40 (2)
N8—C9	1.389 (19)	C17—H17	0.9301
N8—H8	0.8600	C18—C19	1.40 (3)
C9—O10	1.23 (2)	C18—H18	0.9303
C9—C11	1.53 (2)	C19—Cl20	1.751 (16)
C7—C2—C3	121.6 (14)	C9—C11—H11A	109.4
C7—C2—Br1	114.3 (11)	N12—C11—H11B	109.4
C3—C2—Br1	124.1 (12)	C9—C11—H11B	109.4
C4—C3—C2	118.1 (15)	H11A—C11—H11B	108.0
C4—C3—H3	120.9	C13—N12—C11	121.6 (14)
C2—C3—H3	121.0	N12—C13—C6	125.6 (14)
C3—C4—C5	121.7 (15)	N12—C13—C14	116.8 (14)
C3—C4—H4	119.2	C6—C13—C14	117.3 (14)
C5—C4—H4	119.2	C19—C14—C15	117.4 (15)
N8—C5—C4	118.1 (15)	C19—C14—C13	124.2 (14)
N8—C5—C6	122.4 (15)	C15—C14—C13	118.4 (14)
C4—C5—C6	119.3 (14)	C16—C15—C14	121.2 (15)
C7—C6—C5	118.7 (15)	C16—C15—H15	119.4
C7—C6—C13	118.3 (15)	C14—C15—H15	119.4
C5—C6—C13	123.0 (14)	C17—C16—C15	120.0 (14)
C2—C7—C6	120.6 (15)	C17—C16—H16	120.0
C2—C7—H7	119.7	C15—C16—H16	120.0
C6—C7—H7	119.7	C16—C17—C18	120.0 (15)
C9—N8—C5	128.2 (13)	C16—C17—H17	120.0
C9—N8—H8	115.9	C18—C17—H17	120.0
C5—N8—H8	115.9	C19—C18—C17	119.4 (15)
O10—C9—N8	120.5 (13)	C19—C18—H18	120.3
O10—C9—C11	123.4 (13)	C17—C18—H18	120.3
N8—C9—C11	116.1 (14)	C18—C19—C14	121.9 (14)
N12—C11—C9	111.1 (13)	C18—C19—Cl20	118.0 (12)
N12—C11—H11A	109.4	C14—C19—Cl20	120.0 (13)

D—H···A	D—H	H···A	D···A	D—H···A
N8—H8···O10i	0.86	2.15	2.865 (16)	141
C11—H11B···O10ii	0.97	2.18	3.03 (2)	145

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N8—H8⋯O10i	0.86	2.15	2.865 (16)	141
C11—H11B⋯O10ii	0.97	2.18	3.03 (2)	145

Symmetry codes: (i) ; (ii) .