Tetranuclear pyrophosphate-bridged Cu(II) complex with 2,2'-dipyridylamine:Crystal structure,spectroscopy and magnetism

摘要

Use of pyrophosphate,2,2'-dipyridylamine (hdpa) with Cu(NO3)2 centre dot 3H2O has enabled to synthesize a novel tetranuclear copper(II) complex,[Cu4(hdpa)4(mu-P2O7)2] centre dot 11H2O 1,which was characterized by single crystal X-ray diffraction,IR,ESR spectrum,and variable-temperature magnetic susceptibilities (4.2-300 K).Extensive pi-pi stackings and H-bonding water clusters resulting from 11 free water molecules join Cu4 units to make a 3D network.According to the molecular structure,the experimental data were fitted to the expressions derived from the Hamiltonian H = -2J12S1S2 - 2J13(S1S3 + S2S4) - 2J14(S1S4 + S2S4) showing dominant antiferromag-netic behaviors.