New dodecanuclear phenylphosphonate-bridged Co(II) complexes

New dodecanuclear phenylphosphonate-bridged Co(II) complexes [(mu(2)-THF)(5)(eta-HPiv)Co-12(mu(3)-OH)(4)(mu(6)-O3PPh)(4)(mu-Piv)(12)]center dot THF center dot 2C(6)H(6) (1 center dot THF center dot 2C(6)H(6)), [(mu(2)-THF)(6)Co-12(mu(3)-OH)(4)(mu(6)-O3PPh)(4)(mu-Piv)(12)]center dot 3THF (2 center dot 3THF) and [(mu(2)-Hmhp)(6)Co-12(mu(3)-OH)(4)(mu(6)-O3PPh)(4)(mu-Piv)(12)]center dot 6.5MeCN (3 center dot 6.5MeCN) have been synthesized by the reaction of the cobalt(II) pivalate polymer {Co(Piv)(2)}(n) (Piv is the pivalate anion), as a source of metal fragments containing cobalt(II) atoms, with potassium phenylphosphonate (K2PO3Ph) in the presence of neutral O-donor additional ligands like molecules of THF or 6-methyl-2-pyridone (Hmhp). The structures of the dodecanuclear complexes 1-3 were determined by using single-crystal X-ray diffraction data. The magnetic properties of the compounds showed that complexes 1 and 3 exhibit antiferromagnetic exchange interactions between the magnetic centers. The stability of compounds 1 and 3 were studied using thermogravimetric analysis. (C) 2011 Elsevier Ltd. All rights reserved.