Alkyneselenolate vs selenoketenyl coordination: Synthesis and Reactivity of [Ir(SeC⋮CC6H4Me-4)(CO)(PPh3)2]

The reaction of [IrCl(CO)(PPh3)(2)] with LiSeC=CR (R = C6H4Me-4) provides [Ir(SeC=CR)(CO)(PPh3)(2)] (1), which undergoes oxidative addition reactions with oxygen, methyl iodide, benzeneselenenyl chloride and bis(4-tolylethynyl)mercury to provide the complexes [Ir(SeC=CR)(eta(2)-O-2)(CO)(PPh3)(2)] (2), [Ir(CH3)-(SeC=CR)I(CO)(PPh3)(2)] (3), [Ir(CH3)I-2(Co)(PPh3)(2)] (4), [IrCl(SePh)(SeC=CR)(CO)(PPh3)(2)] (5), and [Ir(C=CR)-(HgC=CR)(SeC=CR)(CO)(PPh3)(2)] (6). The complexes 1-3, and 5, and 6 each contain the alkyneselenolate ligand bound to iridium in, a monodentate manner through selenium.