The tetrahydride tricobalt cluster CP*Co-3(3)(mu(2)-H)(3)(mu(3)-H) (1) reduces CO2 at 120 degrees C to form the dicobalt dicarbonyl complex [Cp*Co(mu-CO)](2) (2) in 45% yield by H-1 NMR. 1 reacted with CS2 at room temperature to form the thiocarbonyl cluster CP*Co-3(3)(mu(3)-CS)(mu(3)-S) (3) in 19% isolated yield. 3 was characterized by X-ray crystallography and shown to consist of a triangle of cobalt atoms [Co-Co-(ave) = 2.495 Angstrom] capped on one face by a mu(3)-sulfide Ligand [Co-mu(3)-S-(ave) = 2.129 Angstrom] and on the opposite face by a mu(3)-thiocarbonyl ligand [Co-mu(3)-C-(ave) = 1.949, mu(3)-C-S = 1.634(5) Angstrom]. 1 reacted with phenyl isocyanate at 55 degrees C to form the N,N’-diphenylureylene complex Cp*Co-2(2)(mu(2),mu(2)-eta(2)-PhNCONPh) (5), the dicarbonyl tricobalt cluster CP*Co-3(3)(mu(3)-Co)(2) (6), and the carbonyl dimer 2. 5 was isolated in 13% yield and characterized by X-ray crystallography, which revealed that each nitrogen atom of the eta(2)-N,N’-diphenylureylene ligand was symmetrically bonded to both cobalt atoms [Co-Co = 2.456(1),Co-mu(2)-N-(ave) = 1.959 Angstrom].