Coordination polymers of macrocyclic oxamide with 1,3,5-benzenetricarboxylate: syntheses, crystal structures and magnetic properties

Abstract

Solvothermal reactions of mixed ligands H₃BTC and macrocyclic oxamide complexes (ML, M = Cu, Ni) with M(ClO₄)₂·6H₂O (M = Co, Zn, Ni and Cd) afford six new complexes, including [M′₄(BTC)₂(ML)₂(OH)₂(H₂O)₂]·2H₂O (M′ = Co, M = Ni, for (1); M′ = Zn, M = Ni, for (2); M′ = Zn, M = Cu, for (3)), [Ni₃(BTC)₂(NiL)₂(H₂O)₆]·2CH₃OH·2H₂O (4), [Cd₄(BTC)₂(HBTC)(NiL)₄(H₂O)]·3H₂O (5) and [Cd(HBTC)(CuL)]·H₂O (6) (ML, H₂L = 2, 3-dioxo-5, 6, 14, 15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien; H₃BTC = 1,3,5-benzenetricarboxylic acid). Complexes 1–3 consist of a 2D layer framework formed by the linkage of M(II)(M = Ni, Cu) and M′₄ (M′ = Co, Zn) clustervia the oxamide and BTC³⁻ bridges and display a (3,6)-connected network with a (4³)₂(4⁶.6⁶.8³) topology. The structure of 4 consists of pentanuclear [Ni^II₅] units and arranges in a 1D cluster chain. Complex 5 exhibits a 2D layered structure characterized by 3,4,3-connected (4.6²)₃(4.6³.8²)(4².6³.8)(4².6) topology. Complex 6 possesses a 3D network with sra topology. The magnetic properties of complexes 1 and 4 were investigated.