Chemistry of metal hydrides. VI. Cationic platinum(II) carbonyls stabilized with tertiary arsines and stibines

Abstract

The synthesis of [PtzCI,(R3M),][BF4]z, and its cleavage with carbon monoxide to form the cationic carbonyl species [PtC1(CO)(R3M),]+ is described for R = ethyl or phenyl, and M = As or Sb. A comparison of the physical properties and spectroscopic data of these compounds, and the analogues for M = P is made with related complexes of other transition metals. Unlike their phosphine analogues, these species and the stibine-stabilized cationic carbonyls do not produce the corresponding hydrides on reaction with water in the presence of a salt catalyst. These differences in chemical reactivity are related to the basicity of the ligands.

Si–H and Si–Si activation at Pt: synthesis and reactivity of neutral and cationic silyl complexes

“…The signal appears as a doublet of doublets with J HP(trans) = 147.0 Hz and J HP(cis) = 21.5 Hz. A 1 H, 29 Si HMBC NMR spectrum shows a resonance at d 0.2 ppm in the 29 Si domain, which correlates with the resonances for the hydrido ligand and for the SiPh 2 Me group. The platinumsilyl coupling is 1100 Hz.…”

“…The 31 P NMR spectrum of 8 displays a singlet at d 22.6 ppm with 195 Pt satellites and a platinum-phosphorus coupling constant of 2600 Hz. The 1 H, 29 Si HMBC NMR spectrum shows a cross peak between a signal in the 29 Si domain at d -56 ppm and the resonances for the OCH 2 groups of the silyl group at d( 1 H) 4 ppm. The 1 J SiPt coupling constant is 2150 Hz.…”

Chemistry of metal hydrides. VII. An iridium(III) carbonyl cation and the formation of iridium(III) hydridocarbonyls

“…The latter was lost readily on sublimation to give the pure hydridocarbonyl. The reaction of the iridium(II1) carbonyl perchlorate with water also differed substantially from that of the platinum(I1) carbonyl cation which was converted to hydride (5). In the iridium(II1) case, prolonged reaction of the perchlorate salt with water at 100" did not give a recognizable product, and no spectroscopic evidence could be obtained for hydride formation.…”

“…This is not unexpected. The first chlorine which is readily displaced is trans to a phosphine with a high trans labilizing effect, but in the resulting cation, [IrCI,(CO)(PEt, The platinum carbonyl cations react with methanol and ethanol (4,5) to give stable alkoxycarbonyls, (R,P),PtCl(COOR), and also the preparation of some alkoxycarbonyliridi~~m(II1) complexes has been described recently (14). These include compounds of the type IrC1,-(COOR)(CO)L2 (R = CH3, C2H5, os C,H5 ; L = PMe,Ph or AsMe,Ph) as well as carboxy complexes IrCl,(COOH)(CO)L, which contain the carboxy group -COOH bound directly to a metal.…”

“…While the effects of different ligands on such reactions require further study ( 5 ) , it is also clear that the square planar geometry of these hydrides may be a significant factor. A related study of the chemical behavior of some octahedral transition metal hydrides was therefore thought to be desirable, and for this purpose those of iridium(II1) were chosen because of their stability and detailed characterization (6,7 and refs.…”