Study on Transition-Metal Complexes with Multi-Element Ligands

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The purpose of this project is to create new chemistry of transition metal complexes with a group 13 to 16 element ligand. Transition metal complexes with two or more typical elements in the coordination sphere are also involved in this project. The results obtained are shown below.1. A study on phosphide complexes :Some Zr and Hf complexes with a phosphide-pendant cyclopentadienyl ligand have been prepared. These complexes were found to serve as catalyst for ethylene polymerization and ethylene/stylene copolymerization by a combination with MMAO.2. C-C bond cleavage of organonitriles :An iron silyl complex was found to have the ability to cleave a C-C bond of organonitriles. The theoretical calculation suggested a reasonable reaction pathway. The catalytic cycle to cleave a C-C bond of organonitriles could be established and the reaction mechanism was proposed.3. Iron-catalyzed silylcyanation of aldehyde and ketone :Silylcyanation of aldehyde or ketone was performed in a solution invo … More lving Et_3SiCN produced by photoreaction of Et_3SiH with MeCN in the presence of a catalytic amount of an iron methyl complex. Some iron complex derived from the starting iron complex serves as a catalyst both for C-C bond cleavage of MeCN and concomitant Si-C bond formation and for Si-C bond cleavage in silylcyanation.4. A study on phosphiteboryl complexes :The photoreaction of an Mo methyl complex in the presence of BH_3-P(OMe)(NMeCH_2)_2 produced the phosphiteboryl Mo complex. The complex reacts with MeI and PMe_3 with Mo-B and B-P bond cleavage, respectively, and its thermal reaction leads to B-H bond cleavage.5. A study on phosphenium phosphite complexes :Mo complexes with two or three diamino-substituted phosphite react with TMSOTf to give the corresponding cationic phosphenium phosphite complexes. The X-ray structure analyses and the NMR spectra showed the preferential nonbridging structure. DFT calculations have been incorporated to study the preference of the nonbridging form for phosphenium phosphite complexes, together with the preference of the bridging form for the analogous silylene alkoxysilyl complex. Less