Assembly of Dinuclear CuII Rigid Blocks by Bridging Azido or Poly(thiocyanato)chromates: Synthesis, Structures and Magnetic Properties of Coordination Polymers and Polynuclear Complexes

Abstract

AbstractReaction of a dinuclear cationic copper(II) complex of 4,4′‐[2‐(3‐hydroxyiminobutyl)imino]biphenyl [CuII2(LH)2]2+ with N3– resulted in the formation of a dinuclear azido [CuII2(LH)2(N3)2(H2O)2] complex or a 2D coordination polymer [CuII2(LH)2(N3)2]n. Reaction of the dinuclear complex with [CrIII(NCS)6]3– or [CrIII(NCS)4(NH3)2]– produced a 2D polymer {[CuII2(LH)2(CH3CN)2]3[CrIII(NCS)6]2}n or a 1D chain, constructed from tetranuclear units {[CuII2(LH)2][CrIII(NCS)4(NH3)2]2}n. Structures of the compounds were determined by X‐ray crystallography and complexes were characterised by the temperature dependency of the magnetic susceptibility and by ESR spectroscopy. Magnetic properties of homometallic compounds were fit with the model of a dimer with the Hamiltonian Ĥ = –JŜ1·Ŝ2. For heterometallic complexes χMT curves were fit as the superposition of magnetism resulting from both [CuII2(LH)2]2+ and the adjacent CrIII‐containing anion. J values for the complexes lie in the range from –12.74(4) to –17.77(8) cm–1. It was shown that the 4,4′‐biphenyl bridge efficiently mediates exchange interactions.