Bi- and Mononuclear Nickel(II) Trimethylacetate Complexes with Pyridine Bases as Ligands

Reaction of the nine-nuclear cluster Ni 9 (HOOCCMe 3 ) 4 (μ 4 -ΟΗ) 3 (μ 3 -OH) 3 (OOCCMe 3 ) 12 ( 1 ) with pyridine results in the binuclear species Py 4 Ni 2 (OOCCMe 3 ) 2 (μ-OOCCMe 3 ) 2 (μ-OH 2 ) ( 2 ). Thermolysis of 2 at 100−140 °C in toluene or xylene leads to complex Py 2 Ni 2 (HOOCCMe 3 ) 2 (OOCCMe 3 ) 2 (μ-OOCCMe 3 ) 2 (μ-OH 2 ) ( 3 ). This complex can be converted back in 2 by the reaction of 3 with 2 equiv of pyridine. Thermolysis of solid 3 in vacuo at 170 °C gives the binuclear tetra-bridged trimethylacetate Py 2 Ni 2 (μ-OOCCMe 3 ) 4 ( 4 ) which can be reverted in 3 by reaction with 1 equiv of H 2 O and 2 equiv of HOOCCMe 3 . Compound 4 might be also prepared by the reaction of the complexs L 2 Ni 2 (μ-OOCCMe 3 ) 4 (L = 2,3-lutidine ( 5 ), Et 3 N ( 6 )) with pyridine at 40−80 °C in hexane or benzene solution. Complexes 5 and 6 are formed in an one-step reaction by interaction of complex 1 and ligand L. Complex Dipy 2 Ni 2 (OOCCMe 3 ) 2 (μ-OOCCMe 3 ) 2 (μ-OH 2 ) ( 7 ), an isoelectronic analogue of complex 2, was prepared by reacting 1 with Dipy. Thermolysis of solid 7 at 170 °C in vacuo gives monomer DipyNi(OOCCMe 3 ) 2 ( 8 ). Hetero-ligand complex DipyNi(NH 2 Ph)(OOCCMe 3 ) 2 ( 9 ) was obtained upon the reaction of PhNH 2 with complex 7 at 20 °C in benzene or MeCN. Reaction of 1 with α,α‘,α‘ ‘-tripyridyl leads to the formation of the monomeric TerpyNi(OOCCMe 3 ) 2 ( 10 ). Complexes 4 − 10 were characterized with X-ray data. Magnetic properties of the synthesized complexes are discussed.