meso-4,4′-Difluoro-2,2′-{[(3aR,7aS)-2,3,3a,4,5,6,7,7a-octa­hydro-1H-1,3-benzimidazole-1,3-di­yl]bis­(methyl­ene)}diphenol

Rivera, A.; Quiroga, D.; Ríos-Motta, J.; Kučeraková, M.; Dušek, M.

doi:10.1107/S1600536813000305

Volume 69
Part 2
Page o217
February 2013

Received 24 December 2012
Accepted 3 January 2013
Online 12 January 2013

Key indicators
Single-crystal X-ray study
T = 120 K
Mean (C-C) = 0.002 Å
R = 0.030
wR = 0.077
Data-to-parameter ratio = 12.7
Details

meso-4,4'-Difluoro-2,2'-{[(3aR,7aS)-2,3,3a,4,5,6,7,7a-octahydro-1H-1,3-benzimidazole-1,3-diyl]bis(methylene)}diphenol

Augusto Rivera,^a ^* Diego Quiroga,^a Jaime Ríos-Motta,^a Monika Kuceraková ^b and Michal Dusek ^b

^aFacultad de Ciencias, Departamento de Química, Universidad Nacional de Colombia, Sede Bogotá, Cra 30 No. 45-03, Bogotá, Código Postal 111321, Colombia, and ^bInstitute of Physics, Academy of Sciences of the Czech Republic, v.v.i., Na Slovance 2, 182 21 Praha 8, Czech Republic
Correspondence e-mail: ariverau@unal.edu.co

In the crystal structure of the title compound, C₂₁H₂₄F₂N₂O₂, there are two intramolecular O-HN hydrogen bonds involving the N atoms of the imidazolidine ring and the hydroxy groups. The crystal studied was a meso compound obtained by the reaction of the aminal (2S,7R,11S,16R)-1,8,10,17-tetraazapentacyclo[8.8.1.1^8,17.0^2,7.0^11,16]cosane with 4-fluorophenol. The imidazolidine ring has a twisted conformation with a CH-CH-N-CH₂ torsion angle of 44.99 (14)° and, surprisingly, the lone pairs of the N atoms are disposed in a syn isomerism, making the title compound an exception to the typical `rabbit-ear effect' in 1,2-diamines. In the crystal, molecules are linked via C-HF hydrogen bonds, forming chains along the c-axis direction. These chains are linked via another C-HF hydrogen bond, forming a three-dimensional network.

Related literature

For a related structure, see: Rivera et al. (2011). For a discussion of the `rabbit-ear effect' in 1,2-diamines, see: Hutchins et al.(1968).

Experimental

Crystal data

C₂₁H₂₄F₂N₂O₂
M_r = 374.4
Orthorhombic, P n a 2₁
a = 15.4029 (4) Å
b = 18.7822 (4) Å
c = 6.1639 (2) Å
V = 1783.22 (8) Å³
Z = 4
Cu K radiation
= 0.86 mm^-1
T = 120 K
0.31 × 0.15 × 0.11 mm

Data collection

Agilent Xcalibur (Atlas, Gemini ultra) diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010) T_min = 0.222, T_max = 1
40310 measured reflections
3177 independent reflections
2984 reflections with I > 3(I)
R_int = 0.049

Refinement

R[F² > 2(F²)] = 0.030
wR(F²) = 0.077
S = 1.42
3177 reflections
250 parameters
H atoms treated by a mixture of independent and constrained refinement
_max = 0.15 e Å^-3
_min = -0.11 e Å^-3

Table 1
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
O1-H1N1	0.85 (2)	1.89 (2)	2.6540 (17)	148 (2)
O2-H2N2	0.85 (2)	1.89 (2)	2.6741 (18)	152 (2)
C13-H1C13F2ⁱ	0.96	2.43	3.2645 (19)	145
C17-H2C17F2ⁱⁱ	0.96	2.54	3.356 (2)	142
Symmetry codes: (i) $[-x, -y, z+{\script{1\over 2}}]$ ; (ii) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+1]$ .

Data collection: CrysAlis PRO (Agilent, 2010); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: JANA2006 (Petrícek et al., 2006); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: JANA2006.

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BX2435 ).

Acknowledgements

The authors acknowledge the Dirección de Investigaciones, Sede Bogotá (DIB) de la Universidad Nacional de Colombia, for financial support of this work, as well as the Praemium Academiae project of the Academy of Sciences of the Czech Republic. DQ acknowledges the Vicerrectoría Académica de la Universidad Nacional de Colombia for a fellowship.

References

Agilent (2010). CrysAlis PRO. Agilent Technologies, Yarnton, Oxfordshire, England.
Brandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact, Bonn, Germany.
Hutchins, R. O., Kopp, L. D. & Eliel, E. L. (1968). J. Am. Chem. Soc. 90, 7174-7175.
Palatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786-790.
Petrícek, V., Dusek, M. & Palatinus, L. (2006). JANA2006. Institute of Physics, Prague, Czech Republic.
Rivera, A., Quiroga, D., Ríos-Motta, J., Dusek, M. & Fejfarová, K. (2011). Acta Cryst. E67, o1542.

organic compounds