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

One Cu(II) and two Ni(II) tetranuclear complexes with the hydrated gem-diol form [(C5H4N)2CO(OH), dpd-H] of di-2-pyridylketone as ligand were synthesized, [{Cu4(dpd-H)4(ClO4)2(H2O)2}(ClO4)2 · 2H2O] (1), [{Ni4(dpd-H)4(H2O)4}(ClO4)4 · 4H2O] (2) and [{Ni4(dpd-H)4(OAc)2(H2O)2}(ClO4)2] (3). Complex 1 crystallizes in the triclinic system, space group P1¯, with a = 11.1124 (1), b = 12.731, c = 21.1887(3), α = 75.208(6), β = 78.861(6), γ = 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), β = 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), β = 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 J1 = −6.4 cm−1, J2 = −10.9 cm−1, g = 2.119.

Three new complexes, [{Cu4(dpd-H)4(ClO4)2(H2O)2}(ClO4)2 · 2H2O] (1), [{Ni4(dpd-H)4(H2O)4}(ClO4)4 · 4H2O] (2) and [{Ni4(dpd-H)4(OAc)2(H2O)2}(ClO4)2] (3) have been synthesized and characterized. Single crystal X-ray analysis shows all of them have the same M4O4 (M = Cu, Ni) cubane-like centers.Figure optionsDownload as PowerPoint slide