| II | Introduction | 3 | 
		
			|  | A | Heterogenous Catalysis of CO Reduction | 3 | 
		
			| B | Homogenous Catalysis of CO Reduction | 4 | 
		
			| III | Progress | 6 | 
		
			|  | A | Synthesis and Reactivity Studies of 
			Ketene Clusters | 6 | 
		
			|  | 1 | Insertion of CO into the Os-(u-CH2) bond 
			of Os3(CO)11(u-CH2) | 6 | 
		
			| 2 | Insertion of CO into the Os-methylene Bonds of (OS2(CO)10(U-CH2)(u-X)(X=C1.I.NCO) | 8 | 
		
			| 3 | Reaction of Re(CO)5Br with [Cp(CO)(PPh3)FeC(O)CH21 | 9 | 
		
			| B | Divertive Chemistry of OS3(CO)11(u-CH2) | 10 | 
		
			| C | Formyl, Acyl, Carbene, and Hydride 
			Complexes Derived from the Nitrene-Bridged Cluster Fe3(u-NPh)2(CO)9 
			- Carbene-Nitrene Coupling | 12 | 
		
			| D | Binuclear Formyl and Acyl Complexes | 14 | 
		
			|  | 
		
			| V | References | 19 | 
		
			|  | Figure 1 | 6 | 
		
			| Figure 2 | 11 | 
		
			| Figure 3 | 13 | 
		
			| Figure 4 | 14 | 
		
			| Figure 5 | 15 | 
		
			| Figure 7 | 17 | 
		
			|  | 
		
			| Table I. Vibrational Frequencies of the 
			u-CH2CO ligand in 2 | 7 |