Hydrido rhodium dicarbonyl

Nolte suggested the use of rhodium dicarbonyl dipivaloylmethanate (TMHD = 2,2,6,6-tetramethyl 3,5-heptanedionate, (2)) instead of Rh(acac)(CO)2, which has a longer shelf-life in solution (Scheme 1.21) [38]. Alternatively, [Rh(p-OAc)(COD)]2 (3) or [Rh(p-OMe)(COD)]2 (4) has been used for the generation of rhodium precatalysts [39, 40]. Numerous pieces of evidence were given that also [Rh( i-Cl)(COD)]2 (5), representing a typical precatalyst for hydrogenation, is suitable, for example, for several tandem reactions as well as for heterogenization of rhodium catalysts [41-43]. It should be noted that under hydroformylation conditions the formation of the hydrido rhodium catalyst from the precursors can take considerable time especially at ambient temperature (below 40 °C 5-10 h) therefore sometimes an incubation time is recommended [44]. 

In the case of BDPP with a bite angle of 90°, the high-pressure NMR and high-pressure IR studies showed the structures of the hydrido dicarbonyl diphosphine resting state as an axial-equatorial BPT. Similar behavior was observed for the furanoside diphosphines. Dinuclear rhodium species in equilibrium with the mononuclear pentacoordinate rhodium hydride carbonyl diphosphines have been found for these ligands. The position of this equilibrium depends on the hydrogen concentration and the ligands. The rate... 

OsP2Rh2S2Ci6H3s, Rhodium(I), dicarbonyl-bis- ji-(2-methyI-2-propanethiolato)bis-(trimethyl phosphite)di-, 23 124 O9C0H3OS5C14H13, Osmium, nonacarbonyl-(Ti -cycIopentadienyl)-tri-p.-hydrido-cobalttri-, 25 197... 

On the other hand, reaction of the rhodium(I) hydrido complex RhH(CO)(PPh3)3 with styrene and with carbon monoxide at atmospheric pressure, monitored by NMR spectroscopy, showed the presence of the branched acyl dicarbonyl species given in reaction (o), followed by its isomerization to the linear isomer and formation of the aldehyde. 

PO2WC2SH21, Tungsten, dicarbonyl(T) -cyclopentadienyl)hydrido(triphenyl-phosphine)-, 26 98, 28 7 PO3C3H, Trimethyl phosphite, cobalt and rhodium complexes, 28 283, 284 iron complexes, 26 61, 28 171, 29 158 nickel complex, 28 101 P03C,H,5, Triethyl phosphite, iron complexes, 26 61, 28 171, 29 159 nickel complexes, 28 101,104-106 P03C,H2, Isopropyl phosphite, nickel complex, 28 101... 

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