The synthesis, magnetic properties and crystal structure of a Cu(II) methylenediphosphonate, [Cu 2(O 3PCH 2PO 3)

Abstract

The hydrothermal reaction of Cu(SO 4)·5H 2O, methylenediphosphonate and water in the mole ratio 1.0:1.5:4100 at 150 °C for 48 h yielded clear colorless crystals of [Cu 2(O 3PCH 2PO 3)] ( 1). The structure of 1 is a three-dimensional framework constructed from chains of edge-sharing {CuO 5} trigonal bipyramids linked through the {O 3PCH 2PO 3} 4− subunits. The magnetic data from 35 to 300 K were fit to the Heisenberg linear antiferromagnetic chain model, giving g=1.98 and J/ k B=−35.9 K. At lower temperatures, a Néel transition suggests three-dimensional long-range ordering. Crystal data: CH 2Cu 2O 6P 2, orthorhombic, Pnma, a=13.698(1), b=8.0094(6), c=4.8950(4) Å, V=537.04(7) Å 3, Z=4, D calc=3.699 g cm −3.