Abstract
In this thesis, we studied reactivity of low-coordinate and low-valent dinickel complexes. [Ni(μ-HC(NDep)2)]2 (Dep = 2,6-diethylphenyl) reacted with elemental sulfur to give the complex (μ-S2)2{Ni[μ-HC(NDep)2(S)]}4 (1). In this reaction, sulfur atoms inserted to Ni-N bonds to yield a new ligand contained nitrogen-sulfur bond. On the other hand, [Ni(μ-HC(NDep)2)]2 reacted with pyridine and pyridine N-oxide to furnish the complex {Ni[μ-HC(NDep)2](py)}2 (py = pyridine) (2) and {Ni[μ-HC(NDep)2](py-O)}2 (py-O = pyridine N-oxide) (3). Furthermore, the amidinate- and α-dimine-stabilized dinickel complexes [Ni(μ-HC(NDipp)2)]2 (Dipp = 2,6-diisopropylphenyl), [Ni(μ-HC(NDep)2)]2 and [(o,o’-Dipp-DAB)Ni]2 (o,o’-Dipp-DAB = 2,3-dimethyl-1,4-bis-(2,6-diisopropylphenyl)-1,4-diaza-1,3-butadiene), showed interesting reactivity with diethyl zinc. The following mixed-metal complexes Ni(ZnEt)2[μ-HC(NDipp)2]2 (4), Ni2(ZnEt)2{[Ni(μ-HC(NDep)2)][Ni2(μ-HC(NDep)2)(ZnEt)2]}2 (5) and (η2-C2H4)Ni(o,o’-Dipp-DAB) (6) were isolated accordingly. The formation of these products was presumably controlled by steric hindrance of ligands. Complex 4 contained two Ni-Zn bonds. Complex 5 was a unique metal cluster contained 8 Ni and 6 Zn atoms. Complex 6 contained an ethylene group coordinated to the nickel center. In the second part, we tried to synthesize heteronuclear metal-metal bond complexes. At present, reaction of Li[HC(N-2,6-iPr2C6H3)¬2] with half of an equivalent of MoCl3(THF)3 and WCl3(DME) afforded Mo(Cl)2[μ-HC(NDipp)2]2¬ (7) and W2(μ-Cl)2(Cl)4[μ-HC(NDipp)2]2¬ (8). Both of the metal centers in these two complexes were tetravalent. On the other hand, reaction of Li[HC(N-2,6-Et2C6H3)¬2] and MoCl3(THF)3 gave the mononuclear complex Mo[Cl2(μ-Li(THF)2][μ-HC(NDep)2]2 (9). However, reaction of MoCl3(THF)3 with the more sterically hindered amidinate Li[HC(N-2,6-iPr2C6H3)¬2] gave the quadruply bonded complex Mo2(μ-Cl)[Cl2Li(μ-THF)][μ-η2-HC(N-2,6-iPr2C6H3)2]2.