An unusual coordination polymer containing Cu+ ions and featuring possible Cu...Cu `cuprophilic' interactions: poly[di-μ-chlorido-(μ4-3,5-diaminobenzoato-κ4O:O′:N:N′)tricopper(I)(3 Cu—Cu)]

摘要

Compounds containing copper(I) are of interest for their role in biological processes. The nature of short (< ～3.2??) Cu...Cu contacts within these compounds has been debated, being either described as weakly attractive (bonding) `cuprophilic' interactions, or simply as short metal–metal distances constrained by ligand geometry or largely ionic in nature. The title three-dimensional Cu+-containing coordination polymer, [Cu3(C7H7N2O2)Cl2]n, was formed from the in situ reduction of CuCl2 in the presence of 3,5-diaminobenzoic acid and KOH under hydrothermal conditions. Its complex crystal structure contains ten distinct CuI atoms, two of which lie on crystallographic inversion centres. The copper coordination geometries include near-linear CuOCl and CuN2, T-shaped CuOCl2 and distorted tetrahedral CuOCl3 groups. Each CuI atom is also associated with two adjacent metal atoms, with Cu...Cu distances varying from 2.7350?(14) to 3.2142?(13)??; if all these are regarded as `cuprophilic' interactions, then infinite [01] zigzag chains of CuI atoms occur in the crystal. The structure is consolidated by N—H...Cl hydrogen bonds.