Structural and bonding aspects of molybdenum tricarbonyl complexes of 2,4,6-tritertiarybutyl-1,3,5-triphosphabenzene, P3C3Bu~t_3 and some λ~3,λ~3,λ~5- and λ~3,λ~5,λ~5-alkylated derivatives

摘要

The molecular structure of the previously reported compound [Mo(CO)3(η~6-P3C3Bu_3~t)] has been determined by a single-crystal X-ray diffraction study. Syntheses and molecular structures are also described for the structurally related compounds [Mo(CO)3( η~5-P3C3Bu~t_3)(Me)(Bu~n)], [Mo(CO)3(η~5-P3C3Bu~t_3)(H)(Bu~n)l and [Mo(CO)3(η~4-P3C3Bu~t_3(Me) (Bu~n)(H)(O)Li(THF)3]. Density functional calculations at the B3LYP/cc-pVDZ(-PP) and BP86/cc-pVDZ(-PP) levels have been carried out on the above complexes and the nature of the bonding between the different rings and molybdenum is discussed. ~(31)P NMR spectroscopic evidence is presented for the existence of the novel complex [Mo(CO)3(η~6-P3C3Bu~t_3)PtCl2(PEt3)] in which the triphosphabenzene ring acts as an overall 8-electron donor to the two metal centres.