REACTIONS OF COORDINATED LIGANDS .8. PHOSPHINOFORMIC ACIDS RR'PCOOH (R, R' = ORGANYL, H), THE STILL UNKNOWN P-ANALOGS OF CARBAMINIC ACIDS, STABILIZED AS LIGANDS IN COMPLEXES (CO)5MPRR'COOH (M = CR, W)

Metal carbonyl complexes containing phosphinoformic acids, including t he parent compound H2PCOOH, have been made by the following route: )5M PRR'COOLi-->(CO)5MPRR'COOSiMe3-->(CO)5MPRR'COOH (R = organyl, H; M = C r, W). While the uncoordinated silyl esters RR'PCOOSiMe3 spontaneously decompose to RR'PH, CO2 and Me3SiOH in protic media the last step in the sequence above can be safely brought about by silica gel. So far o nly chromatography on silica gel has been found to provide the mild co nditions necessary to avoid decarboxylation of the ligated esters duri ng protolysis. Some reactions of (CO)5MPRR'COOLi are reported and comp ared with those of the free ligands RR'PCOOLi. The structures of the c omplexes have been confirmed by spectroscopic methods (IR, MS, H-1-, P -31-, C-13-NMR).