A urea complex of copper(II) hypophosphite at 293, 100 and 15 K

The crystal structure of poly[copper(II)-di-mu-hypophosphito-mu-urea], [Cu(H2PO2)2(CH4N2O)]n, has been determined at 293, 100 and 15 K. The geometry of the hypophosphite anion is very close to ideal, with point symmetry mm2. Each Cu atom lies on an inversion centre and is coordinated to six O atoms from four hypophosphite anions and two urea molecules, forming a tetragonal bipyramid. The unique urea molecule lies on a twofold axis. Each hypophosphite anion in the structure is coordinated to two Cu atoms. The hypophosphite anions, urea molecules and Cu(II) cations form polymeric ribbons. The Cu(II) cations in the ribbon are linked together by two hypophosphite anions and a urea molecule, which is coordinated to Cu via an O atom. The ribbons are linked to each other by N-H...O hydrogen bonds and form polymeric layers.