A novel polymeric trinuclear-based mu(3)-phosphato-bridged Cu(II) complex containing two different types of monophosphate. Synthesis, structure and magnetism of {[Cu-3(di-2-puridylamine)(3)(mu(3),eta(3)-HPO4)(mu(3),eta(4)-PO4)(H2O)]-(PF6)(H2O)(3)}(n)

摘要

A novel trinuclear-based polymeric Cu(II) complex with uniquely bridged HxPO4(3-x)- anions, [Cu-3(di-2-pyridylamine)(3)(mu(3),eta(3)- HPO4)(mu(3), eta(4)-PO4)(H2O)](PF6)(H2O)(3)}(n) 1 has been synthesized and characterised. Each Cu(II) ion in the polynuclear unit is linked by hydrogenphosphato and phosphato bridges showing mu(3),eta(3)-HPO42- and an unprecedented mu(3), eta(4)-PO43- coordination mode. Two different coordination geometries around the Cu(II) ions are found in the polynuclear unit: an intermediate geometry between square pyramidal and trigonal bipyramidal and a tetrahedrally distorted square-based pyramidal geometry. The Cu center dot center dot center dot Cu distances vary from 4.408(3) to 5.942(3) angstrom. From variable magnetic susceptibility measurements (5-250 K) a weak antiferromagetic interactions between the Cu(II) ions in the trinuclear unit with an exchange parameter of J = -4.98 cm(-1) and a very weak antiferromagnetic interaction between neighbouring units with zJ' = -1.49 cm(-1) are observed. (c) 2005 Elsevier B.V. All rights reserved.