Hexa-μ2-bromido-μ4-oxo-tetra­kis[(nicotine)copper(II)]

In the title compound, hexa-μ(2)-bromido-μ(4)-oxo-tetra-kis{[3-(1-methyl-2-pyrrolidin-yl)pyridine-κN]copper(II)}, [Cu(4)Br(6)O(C(10)H(14)N(2))(4)], the four Cu atoms are tetra-hedrally arranged around the O atom at the cluster center. The Cu and coordinated N atoms lie along directions which correspond to four of the eight threefold axial directions of a regular octa-hedron. Each Cu atom lies at the center of a trigonal bipyramid, with the O atom and the pyridine N atom of a nicotine ligand in the axial positions and three Br atoms in the equatorial positions. Average bond distances are: Cu-N = 1.979 (8), Cu-O = 1.931 (6), Cu-Br = 2.514 (14) and Cu⋯Cu = 3.154 (6) ÅÅ. The configuration of the nicotine ligands is that of the trans diastereomer. In addition, the crystal structure contains five intra-molecular C-H⋯Br hydrogen bonds, which determine (or support) the orientation of the nicotine mol-ecules relative to their three equatorial Br atoms. One of the nicotine mol-ecules has two C-H⋯Br contacts, while the other three nicotine mol-ecules show only one C-H⋯Br bond each. Two other inter-molecular C-H⋯Br hydrogen bonds connect the complex mol-ecules, forming ribbons which extend in the b- and c-axis directions.