Reactions involving transition metals. Part 16. Rhodium, iridium, platinum, and gold complexes containing the bis(trifluoromethyl)amino-oxy-ligand

Abstract

The stable complexes [Ir{ON(CF3)2}2Cl(CO)L2](L = PPh3, AsPh3, or PMePh2) and [Pt{ON(CF3)2}2(PPh3)2] have been prepared by oxidative addition of the radical (CF3)2NO˙ to trans-[IrCl(CO)L2] and either [Pt(η2-C2H4)(PPh3)2] or [Pt(PPh3)4] respectively. The compounds trans-[IrX(CO)(PPh3)2](X = Br or I) react with the radical to give a mixture of [Ir{ON(CF3)2}2{CO2N(CF3)2}(PPh3)2] and [IrX3(CO)(PPh3)2]. The platinum(II) complexes [Pt{ON(CF3)2}2L2](L = PPh3, AsPh3, or PMePh2) and the gold(I) complex [Au{ON(CF3)2}(PPh3)] have been synthesized by metathetical exchange of the chlorine atoms in cis-[PtCl2L2] and [AuCl(PPh3)] using [Hg{ON(CF3)2)}2]. The weak nucleophile Na[ON(CF3)2] has been shown to react with the complexes [M(CO)(MeCN)(PPh3)2]ClO4(M = Rh or Ir) to give the compounds trans-[M{ON(CF3)2}(CO)(PPh3)2], while reaction with the complexes trans-[PtX(CO)L2]BF4(X = Cl, L = PPh3 or AsPh3; X = Br, L = PPh3) occurs at the carbonyl ligand giving [PtX{CO2N(CF3)2}L2]. The new iridium(I) complex trans-[Ir{ON(CF3)2}(CO)(PPh3)2] forms an oxygen complex in solution, and reacts with halogens, CF3CO2H, HgCl2, and C6H5CH2COCl to give the products [IrX3(CO)(PPh3)2](X = Cl or l), [IrH(O2CCF3)2(CO)(PPh3)2], [IrCl2(HgCl)(CO)(PPh3)2], and [IrCl2(COCH2C6H5)(CO)(PPh3)2] respectively, with loss of the (CF3)2NO ligand; unstable oxidative-addition products [Ir{ON(CF3)2}(R)l(CO)(PPh3)2](R = CF3, CH3, or C2H5) have been characterized from the reactions with iodoalkanes.