Syntheses, Structures, and Reactivities of Mono- and Dinuclear Iridium Thiolato Complexes Containing Nitrosyl Ligands

Reactions of the iridium(III) nitrosyl complex [Ir(NO)Cl2(PPh3)2] (1) with hydrosulfide and arenethiolate anions
afforded the square-pyramidal iridium(III) complex [Ir(NO)(SH)2(PPh3)2] (2) with a bent nitrosyl ligand and a
series of the square-planar iridium(I) complexes [Ir(NO)(SAr)2(PPh3)] (3a, Ar = C6H2Me3-2,4,6 (Mes); 3b, Ar
= C6H3Me2-2,6 (Xy); 3c, Ar = C6H2Pri3-2,4,6) containing a linear nitrosyl ligand, respectively. Complex 1 also
reacted with alkanethiolate anions or alkanethiols to give the thiolato-bridged diiridium complexes [Ir(NO)(μ-SPri)(SPri)(PPh3)]2 (4) and [Ir(NO)(μ-SBut)(PPh3)]2 (5). Complex 4 contains two square-pyramidal iridium(III)
centers with a bent nitrosyl ligand, whereas 5 contains two tetrahedral iridium(0) centers with a linear nitrosyl
ligand and has an Ir−Ir bond. Upon treatment with benzoyl chloride, 3a and 3b were converted into the (diaryl
disulfide)- and thiolato-bridged dichlorodiiridium(III) complexes
(6a, Ar = Mes, n = 2; 6b, Ar = Xy, n = 3) accompanied by a loss of the nitrosyl ligands and cleavage of a C−H
bond in an ortho methyl group of the thiolato ligands. Similar treatment of 4 gave the dichlorodiiridium complex
[Ir(NO)(PPh3)(μ-SPri)3IrCl2(PPh3)] (7), which has an octahedral dichloroiridium(III) center and a distorted trigonal-bipyramidal Ir(I) atom with a linear nitrosyl ligand. The detailed structures of 3a, 4, 5, 6a, and 7 have been
determined by X-ray crystallography.