Dodecacarbonyltriruthenium reacts with certain carboxylic acids, RCO,H ( R = H, Me, Et, or n-CgH19). to give orange, polymeric compounds [Ru(CO),(RCO,)]~.The acetate complex reacts with carbon monoxide under mild conditions to produce a dimeric complex Ru,(CO)~(M~CO,),.In the corresponding reactions with OS,(CO)~, analogous dimeric complexes are isolated in all cases and no evidence for the formation of polymeric dicarbonyl compounds has been found. In certain of these reactions the tetranuclear hydrides, H,M4(CO),,, are produced as secondary products. The polymers and dimers react with ligands such as tertiary phosphines, triphenylarsine or pyridine to produce dimeric complexes of the type M,(CO),(RCO,),L,.The n.m.r., i.r., and mass spectral data of these complexes are reported and discussed PREVIOUSLY we have reported the reactions of dodecacarbonyl-triruthenium and -triosmium with alcohols,2 thiols,l13 arenes? and alkane^.^ In all cases hydridocarbonyl derivatives were isolated either as the major or as a subsidiary product. The formation of these hydrides is of interest and we are examining the reactivity of Ru,(CO),, and Os,(CO),, with a series of organic compounds containing ' active ' hydrogen. We now report the first of these studies, the reactions of Ru,(CO),, and Qs,(CO),~ with carboxylic acids. The reactions of metal carbonyls with carboxylic acids have not been investigated in any detail. Wilkinson and his co-workers have reported the preparation of a series of yellow diamagnetic compounds, Mo2( RCO,),, from the reaction of Mo(CO), with the appropriate carboxylic acid. An X-ray analysis on Mo,(MeCO,), showed that the structure closely resembles those of
