title: 4,4'-Dimethyl-2,2'-{[2,3,3a,4,5,6,7,7a-octa-hydro-1H-benzimidazole-1,3-di-yl]bis-(methyl-ene)}diphenol.
abstract: The asymmetric unit of the title compound, C23H30N2O2, contains one half-mol-ecule, with a twofold axis splitting the mol-ecule in two identical halves. The structure of the racemic mixture has been reported previously [Rivera et al. (2009 ▶) J. Chem. Crystallogr. 39, 827-830] but the enanti-omer reported here crystallized in the ortho-rhom-bic space group P21212 (Z = 2), whereas the racemate occurs in the triclinic space group P-1 (Z = 2). The observed mol-ecular conformation is stabilized by two intra-molecular O-H⋯N hydrogen bonds, which generate rings with graph-set motif S(6). In the crystal, mol-ecules are linked via non-classical C-H⋯O inter-actions, which stack the mol-ecules along the b axis.
authors.affiliation: Universidad Nacional de Colombia, Sede Bogotá, Facultad de Ciencias, Departamento de Química, Cra 30 No. 45-03, Bogotá, Código Postal 111321, Colombia.
authors.forename: Augusto
authors.initials: A
authors.lastname: Rivera
authors.forename: Héctor Jairo
authors.initials: HJ
authors.lastname: Osorio
authors.forename: Mauricio
authors.initials: M
authors.lastname: Maldonado
authors.forename: Jaime
authors.initials: J
authors.lastname: Ríos-Motta
authors.forename: Michael
authors.initials: M
authors.lastname: Bolte
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references.pmid: 17402729
references.citation: Acta Crystallogr A. 2008 Jan;64(Pt 1):112-22
references.pmid: 18156677
references.citation: Dalton Trans. 2012 May 7;41(17):5188-92
references.pmid: 22437916