In situ alkylation of 4,4′-bipyridine in hydrothermal synthesis of one-dimensional copper(I) bromide compounds

Hydrothermal reaction of CuBr2, 4,4′-bipyridine and ethanol/methanol generated two copper (I) bromide complexes with in situ alkylated 4,4′-bipyridium, namely [C14H18N2][Cu5Br7] (1) and [C12H14N2][Cu4Br6] (2). The structure of 1 consists of View the MathML sourceCu5Br72- chains and N ,N ′-diethyl-4,4′-bipyridinium. The underlying structural motif in View the MathML sourceCu5Br72- of 1 is the Cu5Br capped square pyramid, which is different from the Cu5Br2 pentagonal bipyramidal structural motif in various documented View the MathML sourceCu5Br72- anions. The View the MathML sourceCu5Br72- in 1 contains untypical μ5-bromide, with which five copper atoms forms a capped square pyramid rather than a pentagonal pyramid as predicted by Subramanian and Hoffmann. Compound 2 is isostructural with [C12H14N2][Cu4Cl6] reported by Willett, and consists of View the MathML sourceCu4Br62- chains and N ,N ′-dimethyl-4,4′-bipyridinium. The View the MathML sourceCu4Br62- chain is composed of alternating Cu6Br6 and Cu2Br6 units.