Rhodium, hydrido

Rhodium, hydridotetrakis(triphenyl phosphite)-, 4,923 Rhodium, hydrido(trifluorophosphine)tris-(triphenylphosphine)-, 4,921 Rhodium, hydrido(triphenylarsine)tris-(triphenylphosphine)-, 4,921,924 Rhodium, hydridotris(triphenylphosphine)-, 4, 916 preparation, 4, 916... 

Yoshida and Otsuka found that platinum(O) complexes [PtLj] (26) (a L = PEtj b L = P Prj) and rhodium hydrido complexes such as [RhHLj] (L = P Prs 33, PEts), [RhiHidr-NJlPCyslJ (34), tram-[RhH(N2)(PPh Bu2)J, and [RhH(P Bu3)J, all of which carry electron-donating alkylphosphine ligands, can catalyze the water gas shift reaction under fairly mild conditions (100-150°C CO 20 kg/cm ) (Eq. 6.32) [23, 60]. Among these complexes, [RhH(P Pr3)3] (33) was the most active catalyst precursor. Several complexes were isolated from or detected in the reaction mixture... 

This implies that the three frequencies in the hydrido complex are a combination of two CO stretching frequencies and one rhodium hydrido stretching frequency. 

Fig. 6.6. Isomerism in rhodium hydrido carbonyls. The dominant species is the right-hand one...

The proposed mechanism, based on detailed studies [S.-I. Inoue, H. Takaya, K. Tani, S. Otsuka, T. Sato and R. Noyori, J. Am. Chem. Soc., 1990,112, 4897] is schematically represented in Figure 22. Dissociation of one of the BINAP ligands gives the solvated species 1 which coordinates an allylamine molecule affording 11. Complex 11 undergoes (3-elimination to form the transient imi-nium-rhodium hydrido n complex 111. This complex isomerizes to the aza-allyl... 

Since the position of the aldehyde function on the alkyl chain will probably affect the quality of a fixation, we have studied the regioselectivity of the synthesis of aldehyde-functionalized mono- and trialkoxysilanes, using rhodium-hydrido-carbonyl-tris(triphenylphosphine) as catalyst. In general, the hydroformylation of the terminal double bond in organoalkenylsilanes results in the formation of isomeric aldehydes (Eq. 1). 

Reactions of rhodium hydrido complexes with fluoroolefins give migration... 

A series of chiral phosphine-phosphite ligands afforded complexes RhH(L-L)(CO)2 like 25, which showed catalytic activity toward asymmetric hydroformylation. Chiral diphosphite ligands derived from D-(+)-glucose were also coordinated to Rh(l), affording complexes rhodium-hydrido-carbonyl-diphosphite species of the type RhH(PP)(CO)2 (PP = diphosphite), which also proved to be effective asymmetric catalysts for the hydroformylation of vinyl arenes. ... 

For other neutron diffraction smdies of coordinated B—H bonds, see (a) Lam WH, Shimada S, Batsanov AS, et al. Accurate molecular strucmres of 16-electron rhodium hydrido boryl complexes low-temperature single-crystal X-ray and neutron diffraction and computational smcbes of [(PR3)2RhHCl(Boryl)] (Boryl=Bpin, Beat). Organometallics. 2003 22 4557-4568 (b) Hebden TJ, Denney TJ, Pons V, et al. O-Borane complexes of iridium syntliesis and structural characterization. J Am Chem Soc. 2008 130 10812-10820. 

---