Metal–organic frameworks incorporating Cu33-OH) clusters

Abstract
Interaction of 4,4′-bi(1,2,4-triazole) (btr) with copper(II) chloride (bromide) in aqueous or aqueous alcohol media led to a series of coordination polymers featuring the formation of µ3-hydroxotricopper(II) clusters and their integration into 3D frameworks. These unprecedented structures originate in the propagation of trigonal hydroxotricopper(II) clusters bridged by tri- or tetradentate organic ligands. Complex [{Cu33-OH)}{Cu33-O)}(µ4-btr)3(H2O)4(OH)2Cl6]Cl·0.5H2O adopts a structure of SrSi2 topology, with eight-fold interpenetration of the coordination frameworks. The structure of [{Cu33-OH)}23-btr)64-btr)(μ-X)X4]X5·nH2O (X = Br, n = 6; X = Cl, n = 8) involves 2D coordination layers [{Cu33-OH)}(μ3-btr)3]n with an exceptional (3,6)-net topology, which are cross-linked by tetradentate btr ligands and bridging chloride (bromide) ions.