The research proposed has significance in the area of catalysis. The results of this work will aid in the development of the synthetic fuels area. It is proposed to use the complexes, trans-RIr(CO)LL,R = alkyl or alkoxy and L = phosphorus donor, to examine bond forming reactions. These sixteen-electron square planar complexes readily add molecules bringing carbon and hydrogen, oxygen and hydrogen, carbon and carbon, and oxygen and carbon bonds into cis positions on the iridium. In many cases the formation of bonds in a reductive elimination reaction is observed. For instance C-H and O-H bond formation occur by addition of dihydrogen, HX or metal hydrides to trans RIr(CO)L, C-C bond formation occurs by addition of some alkyl halides and acid chlorides to trans RIr(CO)LL (R=alkyl) and C-O bond formation occurs by addition of acid chlorides and aldehydes to trans ROIr(CO)LL. The unique feature of this proposal is the ability to study different bond forming reactions from analogous complexes. Such a systematic investigation may allow a greater understanding of the mechanisms of bond formation by reductive elimination reactions.