4,4'-Dibromo-2,2'-{[(3aS,7aS)-2,3,3a,4,5,6,7,7a-octa-hydro-1H-1,3-benzimidazole-1,3-di-yl]bis-(methyl-idene)}diphenol.

The cyclo-hexane ring in the title compound, C(21)H(24)Br(2)N(2)O(2), adopts a chair conformation and the five-membered ring to which it is fused has a twisted envelope conformation. The asymmetric unit contains one half-mol-ecule, which is related to the other half by a twofold rotation axis. The two N atoms of the five-membered ring are linked to the hy-droxy groups by intra-molecular O-H⋯N hydrogen bonds. In the crystal, inter-molecular C-H⋯O and C-H⋯π inter-actions occur.

Related literature

For a related structure, see: Rivera et al. (2010 ▶). For uses of di-Mannich bases, see: Mitra et al. (2006 ▶).

Experimental

Crystal data

C21H24Br2N2O2

M = 496.2

Orthorhombic,

a = 5.9645 (2) Å

b = 18.5497 (4) Å

c = 9.0494 (2) Å

V = 1001.22 (5) Å3

Z = 2

Cu Kα radiation

μ = 5.32 mm−1

T = 120 K

0.19 × 0.13 × 0.10 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with an Atlas detector

Absorption correction: analytical (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T min = 0.454, T max = 0.678

17493 measured reflections

1749 independent reflections

1739 reflections with I > 3σ(I)

R int = 0.022

Refinement

R[F 2 > 2σ(F 2)] = 0.015

wR(F 2) = 0.049

S = 1.21

1749 reflections

126 parameters

1 restraint

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.11 e Å−3

Δρmin = −0.12 e Å−3

Absolute structure: Flack (1983 ▶), 670 Friedel pairs

Flack parameter: 0.008 (20)

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2009 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SIR2002 (Burla et al., 2003 ▶); program(s) used to refine structure: JANA2006 (Petříček et al., 2006 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: JANA2006.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811006489/ng5118sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811006489/ng5118Isup2.hkl

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

C21H24Br2N2O2	F(000) = 500
Mr = 496.2	Dx = 1.646 Mg m−3
Orthorhombic, P21212	Cu Kα radiation, λ = 1.54184 Å
Hall symbol: P 2 2ab	Cell parameters from 16248 reflections
a = 5.9645 (2) Å	θ = 4.8–66.5°
b = 18.5497 (4) Å	µ = 5.32 mm−1
c = 9.0494 (2) Å	T = 120 K
V = 1001.22 (5) Å3	Prism, colorless
Z = 2	0.19 × 0.13 × 0.10 mm

Oxford Diffraction Xcalibur diffractometer with an Atlas detector	1749 independent reflections
Radiation source: X-ray tube	1739 reflections with I > 3σ(I)
mirror	Rint = 0.022
Detector resolution: 10.3784 pixels mm-1	θmax = 66.8°, θmin = 4.8°
Rotation method data acquisition using ω scans	h = −7→6
Absorption correction: analytical (CrysAlis PRO; Oxford Diffraction, 2009)	k = −10→10
Tmin = 0.454, Tmax = 0.678	l = −21→21
17493 measured reflections

Refinement on F2	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.015	Weighting scheme based on measured s.u.'s w = 1/[σ2(I) + 0.0016I2]
wR(F2) = 0.049	(Δ/σ)max = 0.001
S = 1.21	Δρmax = 0.11 e Å−3
1749 reflections	Δρmin = −0.12 e Å−3
126 parameters	Absolute structure: Flack (1983), 670 Friedel pairs
1 restraint	Flack parameter: 0.008 (20)
45 constraints

Refinement. The refinement was carried out against all reflections. The conventional R-factor is always based on F. The goodness of fit as well as the weighted R-factor are based on F and F2 for refinement carried out on F and F2, respectively. The threshold expression is used only for calculating R-factors etc. and it is not relevant to the choice of reflections for refinement.The program used for refinement, Jana2006, uses the weighting scheme based on the experimental expectations, see _refine_ls_weighting_details, that does not force S to be one. Therefore the values of S are usually larger than the ones from the SHELX program.

	x	y	z	Uiso*/Ueq
Br1	0.55638 (3)	0.229059 (8)	0.146172 (18)	0.02610 (7)
O1	0.99958 (19)	0.42005 (6)	0.59844 (13)	0.0226 (3)
N1	0.59652 (10)	0.44416 (5)	0.71146 (11)	0.0163 (4)
C1	0.5	0.5	0.61175 (12)	0.0154 (6)
C2	0.5511 (3)	0.36959 (8)	0.66196 (17)	0.0165 (4)
C3	0.6757 (3)	0.35153 (7)	0.52184 (17)	0.0156 (4)
C4	0.8947 (3)	0.37777 (8)	0.49815 (18)	0.0174 (4)
C5	1.0085 (3)	0.35992 (9)	0.36866 (19)	0.0204 (4)
C6	0.9120 (3)	0.31499 (8)	0.26478 (18)	0.0205 (5)
C7	0.6975 (3)	0.28860 (8)	0.29074 (18)	0.0180 (4)
C8	0.5810 (2)	0.30615 (8)	0.41680 (17)	0.0160 (4)
C9	0.5029 (3)	0.45921 (8)	0.85825 (17)	0.0179 (4)
C10	0.6319 (3)	0.43125 (9)	0.99165 (18)	0.0268 (5)
C11	0.5129 (4)	0.45880 (10)	1.13117 (19)	0.0322 (6)
H1a	0.382527	0.479008	0.553376	0.0185*
H2a	0.39302	0.363598	0.646178	0.0198*
H2b	0.593539	0.336399	0.738387	0.0198*
H5	1.155662	0.379087	0.351434	0.0245*
H6	0.991627	0.302257	0.176355	0.0245*
H8	0.433442	0.286947	0.43234	0.0192*
H9	0.362416	0.434666	0.870296	0.0214*
H10a	0.782412	0.449589	0.989185	0.0322*
H10b	0.63082	0.3795	0.991145	0.0322*
H11a	0.5957	0.444143	1.217041	0.0386*
H11b	0.367722	0.43676	1.138666	0.0386*
H1o	0.904 (3)	0.4361 (12)	0.657 (2)	0.0272*

	U11	U22	U33	U12	U13	U23
Br1	0.03375 (13)	0.02617 (12)	0.01839 (12)	−0.00261 (7)	−0.00326 (7)	−0.00361 (7)
O1	0.0184 (6)	0.0183 (5)	0.0312 (7)	−0.0015 (4)	−0.0002 (5)	−0.0041 (5)
N1	0.0203 (7)	0.0104 (6)	0.0182 (7)	0.0013 (5)	0.0010 (5)	−0.0010 (5)
C1	0.0145 (10)	0.0119 (9)	0.0197 (10)	0.0006 (7)	0	0
C2	0.0189 (7)	0.0107 (7)	0.0199 (7)	−0.0017 (5)	0.0040 (7)	−0.0010 (6)
C3	0.0185 (7)	0.0095 (6)	0.0188 (7)	0.0034 (6)	0.0013 (6)	0.0036 (6)
C4	0.0176 (7)	0.0110 (7)	0.0236 (8)	0.0019 (5)	−0.0012 (6)	0.0012 (6)
C5	0.0174 (7)	0.0167 (7)	0.0271 (8)	0.0016 (6)	0.0032 (6)	0.0049 (7)
C6	0.0229 (9)	0.0184 (7)	0.0201 (8)	0.0063 (6)	0.0029 (6)	0.0046 (6)
C7	0.0243 (8)	0.0134 (6)	0.0165 (8)	0.0034 (6)	−0.0013 (6)	0.0005 (6)
C8	0.0143 (7)	0.0119 (7)	0.0220 (8)	0.0018 (5)	−0.0021 (6)	0.0023 (6)
C9	0.0215 (8)	0.0153 (8)	0.0169 (7)	0.0023 (5)	0.0009 (6)	0.0022 (6)
C10	0.0437 (10)	0.0176 (7)	0.0191 (8)	0.0094 (6)	−0.0006 (8)	0.0008 (7)
C11	0.0521 (12)	0.0251 (10)	0.0193 (8)	0.0110 (8)	0.0014 (9)	0.0042 (7)

Br1—C7	1.9080 (16)	C5—H5	0.96
O1—C4	1.353 (2)	C6—C7	1.390 (2)
O1—H1o	0.84 (2)	C6—H6	0.96
N1—C1	1.4895 (12)	C7—C8	1.375 (2)
N1—C2	1.4789 (18)	C8—H8	0.96
N1—C9	1.4677 (18)	C9—C9i	1.514 (2)
C1—H1a	0.96	C9—C10	1.523 (2)
C1—H1ai	0.96	C9—H9	0.96
C2—C3	1.507 (2)	C10—C11	1.536 (3)
C2—H2a	0.96	C10—H10a	0.96
C2—H2b	0.96	C10—H10b	0.96
C3—C4	1.410 (2)	C11—C11i	1.536 (3)
C3—C8	1.390 (2)	C11—H11a	0.96
C4—C5	1.394 (2)	C11—H11b	0.96
C5—C6	1.382 (2)
C4—O1—H1o	108.6 (14)	C5—C6—H6	120.6356
C1—N1—C2	113.34 (9)	C7—C6—H6	120.636
C1—N1—C9	105.60 (9)	Br1—C7—C6	119.62 (12)
C2—N1—C9	112.48 (10)	Br1—C7—C8	118.88 (12)
N1—C1—N1i	105.43 (9)	C6—C7—C8	121.48 (15)
N1—C1—H1a	109.4713	C3—C8—C7	120.37 (14)
N1—C1—H1ai	109.4712	C3—C8—H8	119.8142
N1i—C1—H1a	109.4712	C7—C8—H8	119.8142
N1i—C1—H1ai	109.4713	N1—C9—C9i	101.48 (12)
H1a—C1—H1ai	113.2317	N1—C9—C10	117.42 (13)
N1—C2—C3	111.86 (12)	N1—C9—H9	110.1556
N1—C2—H2a	109.4713	C9i—C9—C10	110.62 (13)
N1—C2—H2b	109.4715	C9i—C9—H9	117.0073
C3—C2—H2a	109.471	C10—C9—H9	100.9265
C3—C2—H2b	109.4709	C9—C10—C11	107.74 (15)
H2a—C2—H2b	106.9725	C9—C10—H10a	109.471
C2—C3—C4	120.52 (13)	C9—C10—H10b	109.4714
C2—C3—C8	120.64 (14)	C11—C10—H10a	109.4709
C4—C3—C8	118.78 (14)	C11—C10—H10b	109.4716
O1—C4—C3	121.76 (14)	H10a—C10—H10b	111.1472
O1—C4—C5	118.47 (13)	C10—C11—C11i	112.17 (15)
C3—C4—C5	119.78 (14)	C10—C11—H11a	109.4713
C4—C5—C6	120.83 (14)	C10—C11—H11b	109.4711
C4—C5—H5	119.5819	C11i—C11—H11a	109.4712
C6—C5—H5	119.5833	C11i—C11—H11b	109.4713
C5—C6—C7	118.73 (15)	H11a—C11—H11b	106.632
C2—N1—C1—N1i	138.00 (9)	O1—C4—C5—C6	177.87 (15)
C9—N1—C1—N1i	14.44 (9)	C3—C4—C5—C6	−1.9 (2)
C1—N1—C2—C3	68.53 (14)	C4—C5—C6—C7	0.9 (2)
C9—N1—C2—C3	−171.77 (12)	C5—C6—C7—Br1	177.93 (12)
C1—N1—C9—C10	−157.29 (11)	C5—C6—C7—C8	−0.1 (2)
C1—N1—C9—C9i	−36.62 (13)	Br1—C7—C8—C3	−177.66 (11)
C2—N1—C9—C10	78.61 (16)	C6—C7—C8—C3	0.4 (2)
C2—N1—C9—C9i	−160.72 (12)	N1—C9—C10—C11	175.39 (13)
N1—C2—C3—C4	37.37 (19)	C9i—C9—C10—C11	59.64 (18)
N1—C2—C3—C8	−145.54 (13)	N1—C9—C9i—N1i	45.12 (14)
C2—C3—C4—O1	−0.5 (2)	N1—C9—C9i—C10i	170.46 (12)
C2—C3—C4—C5	179.31 (14)	C10—C9—C9i—N1i	170.46 (12)
C8—C3—C4—O1	−177.62 (14)	C10—C9—C9i—C10i	−64.21 (18)
C8—C3—C4—C5	2.2 (2)	C9—C10—C11—C11i	−55.1 (2)
C2—C3—C8—C7	−178.55 (14)	C10—C11—C11i—C10i	54.8 (2)
C4—C3—C8—C7	−1.4 (2)

Cg2 is the centroid of the C3–C8 ring.

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1o···N1	0.833 (19)	1.905 (18)	2.6506 (13)	148.3 (19)
C1—H1a···O1ii	0.96	2.57	3.3351 (11)	137
C8—H8···Cg2iii	0.96	2.85	3.5407 (16)	130
C11—H11b···Cg2iv	0.96	2.86	3.728 (2)	150

Table 1

Hydrogen-bond geometry (Å, °)

Cg2 is the centroid of the C3–C8 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1o⋯N1	0.833 (19)	1.905 (18)	2.6506 (13)	148.3 (19)
C1—H1a⋯O1i	0.96	2.57	3.3351 (11)	137
C8—H8⋯Cg2ii	0.96	2.85	3.5407 (16)	130
C11—H11b⋯Cg2iii	0.96	2.86	3.728 (2)	150

Symmetry codes: (i) ; (ii) ; (iii) .