Nitrogen- and oxygen-bridged bidentate phosphaalkene ligands

摘要

An overview is given on synthesis and structures of new bidentate phosphaalkene ligands [(RMe2Si)2C=P]2E (E = O, NR, N~-) and (RMe2Si)2C=P-N(R')-PR"2. Exceptional properties of these ligands, extending beyond predictable properties of phosphaalkenes are: (i) the N-Si bond cleavage of [(iPrMe2Si)2C=P]2NSiMe3 with Au~I and Rh~I chloro complexes under mild conditions leading to binuclear complexes of the 6π-delocalised imidobispho-sphaalkene anion [(iPrMe2Si)2C=P]2N~-, and (ii) the chlorotropic formation of molecular 1:2 Pd~(II) and Pt~(II) metallochloroylid complexes with novel ylid-type ligands [(RMe2_ Si)2C=P(Cl)-N(R)-PR2]~-, and the transformation of a P-platina-P-chloroylid complex into a C-platina phosphaalkene by intramolecular chlorosilane elimination. Properties of the heavier congeners [(RMe2Si)2C=P]2E (E = S, Se, Te, PR, P~-, As~-) and (RMe2Si)2C=P-E-PR"2 (E = S, Se, Te) are also described.