Hydrogen-bonded and π-interaction assembly in two 8-alkoxycarbonyl-1,8-diazabicyclo[5.4.0]undec-7-enium chloride salts

Acta Crystallogr C. 2013 Apr;69(Pt 4):444-7. doi: 10.1107/S0108270113005970. Epub 2013 Mar 14.

Abstract

The crystal structures of 8-phenoxycarbonyl-1,8-diazabicyclo[5.4.0]undec-7-enium chloride, C16H21N2O2(+)·Cl(-), (I), and 8-methoxycarbonyl-1,8-diazabicyclo[5.4.0]undec-7-enium chloride monohydrate, C11H19N2O2(+)·Cl(-)·H2O, (II), recently reported by Carafa, Mesto & Quaranta [Eur. J. Org. Chem. (2011), pp. 2458-2465], are analysed and discussed with a focus on crystal interaction assembly. Both compounds crystallize in the space group P2(1)/c. The crystal packings are characterized by dimers linked through π-π stacking interactions and intermolecular nonclassical hydrogen bonds, respectively. Additional intermolecular C-H···Cl interactions [in (I) and (II)] and classical O-H···Cl hydrogen bonds [in (II)] are also evident and contribute to generating three-dimensional hydrogen-bonded networks.