Photochemical synthesis and radical generation of the nickel-tin dimer [Ni(SnBut3)(CNBut)2(CO)]2

Ni(COD)2 reacts with But3SnH and CNBut at room temperature to afford the trigonal bipyramidal complex Ni(SnBut3)2(CNBut)3, 3. Exposing a solution of 3 to CO gas results in ligand exchange generating the pale yellow complex, Ni(SnBut3)2(CNBut)2(CO), 4. In the presence of light, a Ni-Sn bond in 4 is cleaved converting two equivalents of compound 4 into the deep purple nickel-tin dimer, [Ni(SnBut3)(CNBut)2(CO)]2, 5. The reaction is believed to proceed through radical mechanisms.