Three new cubane-like transition metal complexes of di-2-pyridyl ketone in gem-diol form: Syntheses, crystal structures and properties

摘要

One Cu(II) and two Ni(II) tetranuclear complexes with the hydrated gem-diol form [(C5H4N)(2)CO(OH), dpd-H] of di-2-pyridylketone as ligand were synthesized, [{Cu-4(dpd-H)(4)(ClO4)(2)(H2O)(2)}(ClO4)(2) center dot 2H(2)O] (1), [{Ni-4(dpd-H)(4)(H2O)(4)}(ClO4)(4) center dot 4H(2)O] (2) and [{Ni-4(dpd-H)(4)(OAc)(2)(H2O)(2)}(ClO4)(2)] (3). Complex 1 crystallizes in the triclinic system, space group P!, with a = 11.1124 (1), b = 12.731, c = 21.1887(3), alpha = 75.208(6), beta = 78.861(6), gamma = 72.626(6), and Z = 2. Complex 2 crystallizes in the monoclinic system, space group C2/c, with a = 21.9000(3), b = 12.8052(1), c = 21.3072(2), beta = 90.576(1) and Z = 4. Complex 3 crystallizes in the monoclinic system, space group C2/c, with a = 23.07500(10), b = 12.0977(4), c = 21.1347(6), beta = 116.5090(10) and Z = 4. Single crystal X-ray analyses show 1, 2 and 3 all have the same M4O4 (M = Cu, Ni) cubane-like centers. Variable temperature magnetic susceptibility measurement for 1 indicates an overall antiferromagnetic interaction and two groups of parameters are obtained in two different models with J = J' = -12.1 cm(-1), g = 2.13, or J(1) = -6.4 cm(-1), J(2) = 10.9 cm(-1), g = 2.119. (C) 2005 Elsevier Ltd. All rights reserved.