title: Self-assembled polynuclear clusters derived from some flexible polydentate dihydrazide ligands.
abstract: Polynuclear manganese(II), cobalt(II)/(III), iron(II)/(III) and nickel(II) complexes of a group of flexible polydentate dihydrazone ligands, based on pyridine-2,6-dipicolinic (A), oxalic (B) and malonic (C) subunits are described. Structural details are reported for the linear dinuclear complexes [Ni2(2poap)2(H2O)2](NO3)4 . 2CH3OH . 2.5H2O (1), [Mn2(pttp)(NO3)2(CH3OH)2(H2O)2](NO3)2 . H2O (2) and [Mn2(mapttp)2(NO3)2(H2O)2](NO3)2 . 10H2O (3), a square tetranuclear complex [Co4(pttp)4]Br6 . 9H2O (4), a tetranuclear tetrahedral complex [Ni4(pttp)6](BF4)6F2 . 14H2O (7), and a mixed spin state tetranuclear Ni(II) complex [(2pyoap)2Ni4(CH3OH)4] . 1.5CH3OH (10), with a diamond-like arrangement of metal ions. The paramagnetic metal centers are well separated in each case, leading to weak antiferromagnetic coupling or non-existent spin exchange.
authors.affiliation: Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X7, Canada.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.forename: Virginie
authors.initials: V
authors.lastname: Niel
authors.forename: Laurence K
authors.initials: LK
authors.lastname: Thompson
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Xu
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Milway
authors.forename: Rosemary G
authors.initials: RG
authors.lastname: Harvey
authors.forename: David O
authors.initials: DO
authors.lastname: Miller
authors.forename: Claire
authors.initials: C
authors.lastname: Wilson
authors.forename: Michael
authors.initials: M
authors.lastname: Leech
authors.forename: Judith A K
authors.initials: JA
authors.lastname: Howard
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Heath