Reaction of [RuCl2(DMSO)4] with aromatic phosphines bearing ortho-methoxy groups
†
Abstract
Reaction of [RuCl2(DMSO)4] 1 with (2,6-dimethoxyphenyl)diphenylphosphine (MDMPP) in acetone–CH2Cl2 at reflux gave t,c,c-[RuCl2(MDMPP-κ2P,O)2] 2. Reaction with bis(2,6-dimethoxyphenyl)phenylphosphine (BDMPP) afforded the phosphonium salt containing a ruthenium(II) anion, [BDMPP(CH2Cl)][RuCl3(DMSO)3] 3b, [BDMPP(CH2Cl)][RuCl(DMSO)2{PPh(C6H3OMe-6-O-2)2-κ3P,O,O′)] 4b and [BDMPP(CH3)][RuCl (DMSO)2{PPh(C6H3OMe-6-O-2)2-κ3P,O,O′)] 4d [BDMPP(CH2Cl) = {2,6-(MeO)2C2H3}2PhP(CH2Cl), BDMPP(CH3) = {2,6-(MeO)2C6H3}2PhP(CH3)]; complexes 4 contain tridentate P,O,O′ co-ordination in which two methoxy groups of BDMPP were demethylated. These structures were confirmed by X-ray analyses. Tris(2,6-dimethoxyphenyl)phosphine (TDMPP) reacted with 1 to give 3c [TDMPP(CH2Cl)][RuCl3(DMSO)3] [TDMPP(CH2Cl) = {2,6-(MeO)2 C6H3}3P(CH2Cl)]. Complex 2 reacted with xylyl or mesityl isocyanide to give mer-[RuCl2(MDMPP-P)(RNC)3] 5. Reaction with CO afforded [RuCl2(MDMPP-P)(MDMPP-κ2P,O)(CO)] 6 and an insoluble unidentified complex. The structure of 6 was confirmed by an X-ray analysis; one MDMPP group acts as a P,O bidentate ligand, the other as a monodentate ligand, and a CO ligand occupies the trans position to an oxygen atom. Two Cl and two P atoms were located at mutually trans positions. The phosphonium salt [BDMPP(CH2Cl)]Cl, derived from CH2Cl 2 and BDMPP, reacted with 1 to afford 3b. The reaction of 3b with BDMPP gave 4b and 4d. The reaction pathways are discussed.