Research Article: 6,6′-Dimethyl-2,2′-[1,3-diazinane-1,3-diyl­bis(methyl­ene)]diphenol

Date Published: March 01, 2012

Publisher: International Union of Crystallography

Author(s): Augusto Rivera, Derly Marcela González, Jaime Ríos-Motta, Karla Fejfarová, Michal Dušek.


In the mol­ecule of the title compound, C20H26N2O2, the 1,3-diazinane ring adopts a slightly distorted chair conformation and the hy­droxy­benzyl substituents occupy equatorial positions on the N atoms of the heterocyclic ring. There are two intra­molecular O—H⋯N hydrogen bonds between the N atoms of the 1,3-diazinane ring and the hy­droxy groups of the aromatic rings, with an S(6) set-graph motif. However, the two observed intra­molecular hydrogen-bond distances were different. Considering that both N atoms experience the same chemical environment, it is surprising to see the difference in O⋯N distances [2.6771 (14) and 2.8123 (12) Å]. The crystal structure is further stabilized by a C—H⋯π interaction.

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For a previous determination of a related structure, see: Rivera et al. (2012 ▶). For a related di-Mannich base, see: Rivera et al. (2009 ▶). For the synthesis of the precursor, see: Rivera et al. (2010 ▶). For bond-length data, see: Allen et al. (1987 ▶). For Cremer–Pople puckering parameters, see: Cremer & Pople (1975 ▶). For hydrogen-bond graph-set nomenclature, see: Bernstein et al. (1995 ▶). For the background to hydrogen-bond energy in Mannich bases, see: Koll et al. (2006 ▶).