Crystal structure of di-μ-chlorido-bis{chlorido[(−)-5,6-pinenebipyridine]cobalt(II)} aquadichlorido[(−)-5,6-pinenebipyridine]cobalt(II)

Abstract

The crystal structure of [Co2Cl4(C17H18N2)2][CoCl2(C17H18N2)(H2O)] or [Co(L)Cl(μ-Cl)]2[Co(L)(Cl)2(OH2)], where L is the enantiopure bidentate ligand (−)-5,6-pinenebipyridine (C17H18N2), has been determined. Crystals suitable for X-ray structure analysis were obtained by slow evaporation of an ethanolic solution containing equimolar amounts of L and CoCl2·6H2O. The CoII cations all have a coordination number of five, and in each case the coordination polyhedron is a trigonal bipyramid. The Co—N bonds lengths range from 2.037 (7) to 2.195 (7) Å, and Co—Cl bonds lengths range from 2.284 (2) to 2.509 (2) Å. The asymmetric unit contains two discrete complexes, one dinuclear and the other mononuclear. Between the two molecules, two types of intermolecular interactions have been evidenced: π–π stackings involving the bipyridine units, and O—H...Cl hydrogen bonds between the hydrogen atoms of the aqua ligand coordinating to the mononuclear complex and the non-bridging chlorido ligand coordinating to the dinuclear molecule. These interactions lead to a two-dimensional supramolecular arrangement parallel to the ab plane.