172613-00-2Relevant academic research and scientific papers
Thermal isomerization of mer-[RhH(SAr)(SiHAr'2)(PMe3)3] to fac- [RhH2{SiAr'2(SAr)}(pme3)3] involving thiolato group transfer from Rh to Si
Osakada, Kohtaro
, p. 2853 - 2858 (2007/10/03)
Heating of a benzene or toluene solution of mer- [RhH(SAr)(SiHAr'2)(PMe3)3] (Ar = C6H5, C6H4Me-p, C6H4OMe-p; Ar' = C6H5, C6H4Me-p, C6H4F-p, C6H4CF3-p) at 30 - 50 °C gives fac-[RhH2 {SiAr2(SAr)}(PMe3)3] quantitatively through thiolato group transfer from Rh to Si. X-Ray structural analysis of fac-[RhH2{SiPh2(SPh)}(PMe3)3] reveals octahedral coordination with three PMe3 ligands at facial coordination sites, while the J H NMR spectra show the presence of two equivalent hydrido ligands. The other Rh complexes are isolated or characterized in situ by means of NMR spectroscopy. The reaction of mer- [RhH(SC6H4Me-p)(SiHPh2)(PMe3)3] to form the Rh complex obeys first- order kinetics with the kinetic parameters: ΔG(+) = 98.6 kJ mol-1 ΔH(+), = 94.9 kJ mol-1 and ΔS(+) = 1 12 J mol-1 deg-1 at 298 K. The rate constants of the reaction of mer-[RhH(SC6H4X-p)(SiHPh2)(PMe3)3] (X = H, Me, OMe) increase with increasing Hammett constant σ of substituent X. The substituent of the diarylsilyl ligand of mer-[RhH(SC6H4X-p){SiH(C6H4Y- p)2}(PMe3)3] (X = Me or OMe; Y = H, Me, F, CF3) also influences the reaction rate constant, while the degree of enhancement is not directly related to the electron donating or withdrawing ability of substituent Y. Possible reaction mechanisms are discussed based on these results.
Unique Intramolecular Exchange between H of SiHPh2 and SAr in
Osakada, Kohtaro,Hataya, Kouji,Yamamoto, Takakazu
, p. 2315 - 2316 (2007/10/02)
mer-, prepared from oxidative addition of H2SiPh2 to Rh(SAr)(PMe3)3, undergoes transfer of the thiolato ligand to the coordinated Si atom to give fac-(PMe3)3>.
