Reactions involving transition metals. Part 14. The preparation of novel alkyl peroxy(carboxylato)iridium(III) complexes

Abstract

Treatment of the di(alkyl peroxy)iridium(III) complexes [IrX(O₂R¹)₂(CO)(PPh₃)₂](X = Cl or Br) with organic acids, R²CO₂H, having a pK_a > ca. 4.0 results in the substitution of only one of the alkyl peroxy-ligands with formation of [IrCl(O₂R¹)(OCOR²)(CO)(PPh₃)₂](R¹= Bu^t, R²= CF₃, CCl₃, CHCl₂, CO₂H, cis-CHCHCO₂H, C₆F₅, or H; R¹= CMe₂Ph, R²= CF₃), and [IrBr(O₂Bu^t)(OCOR²)(CO)(PPh₃)₂](R²= CF₃ or H). The related compounds [IrX(Y)(O₂Bu^t)(CO)(PPh₃)₂](X = Y = Cl or Br; X = Cl, Y = Br or NO₃) have also been obtained by reaction of [IrX(O₂Bu^t)₂(CO)(PPh₃)₂](X = Br or Cl) with HCl, HBr, or HNO₃ at 0 °C. At higher temperatures [IrCl₂(O₂Bu^t)(CO)(PPh₃)₂] and [IrCl(O₂Bu^t)(OCOCCl₃)(CO)(PPh₃)₂] react with HCl to give [IrCl₃(CO)(PPh₃)₂].