Homobinuclear Ru-Ru and heterobinuclear Ru-Rh complexes with alkynyl and vinylidene ligands as molecular units

Abstract

The chelate complex [RuCl 2 {κ 2 (P,O)-i-Pr 2 PCH 2 CH 2 OMe} 2 ] (1) reacted, in the presence of CF 3 SO 3 Ag, with 1 equiv of C 6 H 4 (CºCH) 2 -p (4) to afford the mononuclear vinylidene compound [RuCl(C=CHC 6 H 4 -p-CºCH){κ 2 (P,O)-i-Pr 2 PCH 2 CH 2 OMe} 2 ](CF 3 SO 3 ) (3). From 1 and 0.5 equiv of 4, the binuclear bis(vinylidene) complex [RuCl{κ 2 (P,O)-i-Pr 2 PCH 2 CH 2 OMe} 2 (C=CHC 6 H 4 -p-CH=C)RuCl{κ 2 (P,O)-i-Pr 2 PCH 2 CH 2 OMe} 2 ](CF 3 SO 3 ) 2 (6) was obtained. The related compound [RuCl{κ 2 (P,O)-i-Pr 2 PCH 2 CH 2 OMe} 2 (C=CHC 6 H 4 -m-CH=C)RuCl{κ 2 (P,O)-i-Pr 2 PCH 2 CH 2 OMe} 2 ](CF 3 SO 3 ) 2 (7) was prepared from 1, 0.5 equiv of C 6 H 4 (CºCH) 2 -m (5), and silver triflate. The reaction of 2 or 3 with [RhCl(P-i-Pr 3 ) 2 ] 2 (8) in the molar ratio of 2:1 yields, by addition of the 14-electron fragment [RhCl(P-i-Pr 3 ) 2 ] to the uncoordinated C—C triple bond, the heterobinuclear complexes [RuCl{κ 2 (P,O)-i-Pr 2 PCH 2 CH 2 OMe} 2 (C=CHC 6 H 4 -m/p-CºCH)RhCl(P-i-Pr 3 ) 2 ](CF 3 SO 3 ) (9, 10) which slowly rearrange at room temperature to give the bis(vinylidene) isomers [RuCl{κ 2 (P,O)-i-Pr 2 PCH 2 CH 2 OMe} 2 (C=CHC 6 H 4 -m/p-CH=C)RhCl(P-i-Pr 3 ) 2 ](CF 3 SO 3 ) (11, 12).Key words: ruthenium, rhodium, vinylidene complexes, alkyne complexes, phosphine complexes.