|Budget Amount *help
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2002: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2001: ¥1,300,000 (Direct Cost: ¥1,300,000)
Various polymers of sterically protected 3,4-diphosphinidenecyclobutenes, which are unique bidentate ligands having phosphorus-carbon double bonds, were prepared and their properties were studied. For example, a new sterically protected 3,4-diphosphinidenecyclobutene, containing 4-(4-vinylphenyl)butyl group at the 1- and 2-positions, was prepared and converted to a polymer. In the successive reaction of bis[(2,4,6-tri-t-butylphenyl)phosphino]diynes with t-butyllithium and 1,2-dibromoethane, 3,4-diphosphinidenecyclobutene derivatives having ring-fused structures were obtained as major products along with diphosphinidenecyclobutene polymers. Sterically protected 3,4-diphosphinidene-1,2-dithienylcyclobutenes were also prepared and converted to polymers and/or oligomers, via functionalization of the thienyl moieties. Some polymers and oligomers, as well as their monomers, were allowed to react with bis(acetonitrile)dichloropalladium or bis(acetonitrile)dichloroplatinum to give metal comple
xes of the bidentate ligands. Structures of some diphosphinidenecyclobutene monomers and their transition metal complexes were analyzed by X-ray crystallography. A relatively large geometrical change induced by the complex formation was exhibited in the case of 3,4-diphosphinidenecyclobutenes having ring-fused structures.
Moreover, some new sterically protecting groups were developed. A sterically protecting auxiliary of the metacyclophane type was newly developed and applied to preparations of unsymmetrically substituted diphosphene and 1,3-diphosphaallene. Unsymmetrical 1,4-diphosphabutatriene was prepared for the first time, using the sterically protecting group of metacyclophane type, and the properties were studied. Sterically hindered aryl substituents having an electron-donating group at the o- or p-positions, were also developed. Thus, 2,4-di-t-butyl-6-(phenoxymethyl)phenyl group and 2,6-di-t-butyl-4-methoxyphenyl group were developed and the substituents were applied to preparations of diphosphenes as well as dichlorophosphines and fluorenylidenepbosphines. Structures of some low coordinated phosphorus compounds bearing the electron-donating sterically demanding groups were studied by X-ray crystallography and the effect of the substituents were discussed. Less