122698-90-2Relevant academic research and scientific papers
Synthesis and structural studies of some new rhenium phosphine heptahydride complexes. Evidence for classical structures in solution
Luo, Xiao-Liang,Crabtree, Robert H.
, p. 4813 - 4821 (1990)
A series of new rhenium phosphine heptahydride complexes ReH7L2 (L2 = a chelating bidentate phosphine) have been synthesized and characterized by IR and 1H, 31P, and 13C NMR spectroscopy. The hydride resonances of ReH7(dppf) (1,dppf = 1,1'-bis(diphenylphosphino)ferrocene), ReH7dppb) (2, dppb = 1,4-bis(diphenylphosphino)butane),and ReH7(+)-diop| (3, (+)-diop = (4S,5S)-4,5-bis((diphenylphosphino)methyl)-2,2-dimethyl-1,3-dioxolane) undergo decoalescence upon cooling. The low-temperature hydride patterns suggest classical 9-coordinate tricapped trigonal prismatic structures. Consistent with the classical structures, 1H NMR spectra of deuterated ReH7L2 complexes show very small and temperature-independent upfield isotope shifts in the hydride region and no change in VHP- Sequential treatment of 1, 2, and 3 with NaH and Mc2SO4 in the presence of Ph3SiH leads to ReH6(SiPh3)L2 (L2 = dppf, dppb, (+)-diop). Variable-temperature 1H NMR studies of these silyl derivatives provide further support for the classical formulation of their parent heptahydrides. Theoretical 7, (min) values are calculated for some polyhydrides on the basis of different structural models and are compared with the experimental numbers. Precautions to be taken in interpreting T1 data are discussed.
