C-S bond cleavage of 2-methoxythiophene by Ir-TMEDA complex (TMEDA = N,N,N′,N′-tetramethylethylenediamine).: Formation of novel dinuclear iridathiacyclohexenyl complex

The Ir-TMEDA complex [Ir(C2H4)(2)(TMEDA)(MeCN)][BF4] (TMEDA = Me2NCH2CH2NMe2) was treated with 2-methoxythiophene in MeCN at 70 degrees C in the presence of H2O to afford the novel dinuclear iridathiacyclohexenyl complex [Ir-2{C(OMe)CHCHCH(CMe=NH)S}(MeCONH)(TMEDA)(2)][BF4](2) in 42% yield, in which two Ir(TMEDA) fragments, one 2-methoxythiophene, and two MeCN molecules are incorporated together with one H2O molecule. The mechanism that involves the insertion of the Ir center into the thiophenic S-C(OMe) bond followed by the pi-coordination of the second Ir center to the thiametallacycle has been proposed. (C) 2008 Elsevier B.V. All rights reserved.