Metal complexes with sulfur and selenium donor ligands

Abstract

Treatment of [Ir(H)(PCy3)2Cl2] with K[N(Pri2PS)2] yielded the iridium(III) hydride complex cis-[Ir(H)(PCy3){N(Pri2PS)2}2], which could be protonated by HBF4 to give a dicationic cis-[Ir(H)(PCy3){HN(Pri2PS)2}2][BF4]2. Reaction of [Ir(COE)2{N(Pri2PS)2}] with PPh3 gave a iridium bis-triphenylphosphine complex [Ir(PPh3)2{N(Pri2PS)2}]. A series of rhodium triphenylphosphine complexes with [N(R2PQ)2]- ligands, [Rh(PPh3)2{N(R2PQ)2}], have been synthesized from reaction of [Rh(PPh3)3Cl] with K[N(R2PQ)2] (R = Pri, But; Q = O, S and Se). [Rh(PPh3)2{N(Pri2PQ)2}(η2-O2)] (Q = S, Se) were isolated when [Rh(PPh3)2{N(Pri2PQ)2}] were recrystallized for a long time with leakage of air. [Rh(PPh3)2{N(Pri2PS)2}] can catalyze the hydrosilylation of acetophenone with H2SiPh2. [Rh(PPh3)2{N(Pri2PS)2}] underwent reversible oxidative addition with triethylsilane and benzoyl chloride to give [Rh(H)(PPh3){N(Pri2PS)2}(SiEt3)] and [Rh(COPh)(PPh3)2{N(Pri2PS)2}(Cl)], respectively. Reaction of [Rh(PPh3)2{N(Pri2PS)2}] with HCl gave a mixture of [Rh(PPh3){N(Pri2PS)2}2Cl] and a Rh-hydride species. Oxidative addition of [Rh(PPh3)2{N(Pri2PQ)2}] (Q = S, Se) with MeI afforded five-coordinated Rh(III) complexes [Rh(PPh3){N(Pri2PQ)2}(CH3)I]. Treatment of [Rh(PPh3){N(Pri2PS)2}(CH3)I] with K[N(Pri2PS)2] resulted in the formation of the bis-chelated Rh-methyl complex [Rh(CH3){N(Pri2PS)2}2], which could be protonated by triflic acid to give dicationic [Rh(CH3){HN(Pri2PS)2}2][OTf]2. Reaction of [Ru(=CHPh){N(Pri2PS)2}(PCy3)Cl] with excess NaOMe led to the formation of the ruthenium hydride complex [Ru(H){N(Pri2PS)2}{PCy2(η2-C6H9)}] containing a κ3-dicyclohexyl(η2-cyclohex-3-enyl) phosphine ligand. The formation of the hydride complex involved a Ru-hydride benzylidene intermediate derived from β-hydrogen elimination of a Ru-OMe precursor, followed by double intramolecular C-H activation of a cyclohexyl group in PCy3. Treatment of [Et4N]2[WSe4] with dimethyl and diethyl acetylenedicarboxylate afforded the [2+3] cycloaddition adducts [Et4N]2[W(η2-C2(CO2R)2){Se2C2(CO2R)2}2] (R = Me, Et). These WIV bis(diselenolene) complexes have a distorted trigonal prismatic geometry containing a η2-alkyne ligand that act as 4-electron donor ligand. In addition, a small amount of [Et4N]2[W(Se){Se2C2(CO2Me)2}2], which may be formed by reaction of [Et4N]2[W(η2-C2(CO2Me)2){Se2C2(CO2Me)2}2] with the Se derived from the decomposed [WSe4]2-, was isolated.

Date of Award	2009
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology