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

Use of pyrophosphate, 2,2′-dipyridylamine (hdpa) with Cu(NO3)2 · 3H2O has enabled to synthesize a novel tetranuclear copper(II) complex, [Cu4(hdpa)4(μ-P2O7)2] · 11H2O 1, which was characterized by single crystal X-ray diffraction, IR, ESR spectrum, and variable-temperature magnetic susceptibilities (4.2–300 K). Extensive π–π 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 image showing dominant antiferromagnetic behaviors.