A study of the photochemistry and thermal chemistry of Ru3(CO)9(PR3)3{R = Ph, OMe} with two-electron donor ligands

Abstract

The photochemistry of the tris-substituted clusters Ru3(CO)9(PR3)3 (R = Ph or OMe) with no added ligands, with CO, C2H4, alkynes and H2 is compared and contrasted with results obtained for analogous thermal reactions. Photolysis of a CH2Cl2 solution of Ru3(CO)9(PPh3)3 leads to the metallated complex HRu3(CO)8(PPh3)2(PPh2C6H4). In CCl4, Ru(CO)3(PR3)Cl2 is formed on photolysis of Ru3(CO)9(PR3)3. Photolysis of CO saturated solutions of Ru3(CO)9(PR3)3 leads to Ru(CO)4(PR3). C2H4 saturated solutions of Ru3(CO)9(PR3)3 generate the novel Ru(CO)3(PR3)(η2-C2H4) complexes upon photolysis. With C2H2, photolysis of solutions of Ru3(CO)9(PR3)3 leads to the novel complexes Ru(CO)3(PR3)(η2-C2H2). Substituted alkyne complexes have been prepared. Thermolysis of Ru3(CO)9(PR3)3 with HC≡CPh leads to the novel acetylide clusters HRu3(CO)6(PR3)3(μ3-η2-C2Ph). With PhC≡ CPh, only Ru3(CO)9{P(OMe)3}3 reacts, yielding the novel alkyne cluster Ru3(CO)6{P(OMe)3}3(μ3-η2-C2Ph2). With H2, photolysis of CH2Cl2 solutions of Ru3(CO)9(PR3)3 leads to H2Ru(CO)2(PR3)2. Irradiating a 4:1 CH2Cl2 to EtOAc solution of Ru3(CO)9(PR3)3 under an atmosphere of H2 leads to the novel dihydrido species H2Ru3(CO)7(PR3)3. Thermolysis of H2 saturated solutions of Ru3(CO)9(PR3)3 leads to H4Ru4(CO)8(PR3)4.