Nickel compounds tetranuclear complexes

Kockerling, M. and Henkel, G. (2000) Synthesis and structure of [Ni4(S2C7Hio)4], the first tetranuclear cyclic nickel complex with bifunctional thiolate ligands and of the mononuclear precursor compound Na2[Ni(S2C7Hio)2]- 4MeOH. (PrOH)-Pr-i, Inorg. Chem. Commun., 3, 117-9. 

The tetrahedral [160-163] and cis-planar [100,134,164-167] structures are characteristic for chelates of type 874 with coordination units NiN4 and MN2S2, respectively, as well as chelates 868 discussed above. Original polyhedral forms were discovered by x-ray diffraction for nickel and palladium ICC of the discussed type 874. It is accepted that, in case of a nickel complex, the compound with a carbon-carbon bond 875 is formed [165,166] formation of palladium chelates is accompanied by the cyclometallation reaction leading to tetranuclear clusters 876, where the tridentate ligand behaves as C,N,S-donor [168]. 

The hydrolysis of [Ni(H20)6p has been studied by some authors. It has been found that polynuclear species are formed in alkaline solution, e main product being the tetranuclear cation [Ni4(OH)4] . " A few solid compounds which contain nickel(II) linked only to hydroxide ions were reported, namely M2[Ni(OH)6] (M = Ba, Sr) and Na2[Ni(OH)4]. " The chemistry of oxo compounds of nickel(n) is very limited if the simple oxide NiO and the mixed-metal oxide BaaNiOa are excluded. Dioxygen complexes of nickel(II) are not cited in a recent review article. ... 

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