Reactions of hydrogen with ruthenium and osmium complexes containing tridentate ligands Cy2PCH2CH(CH2)2PCy2 and 2,6-(Ph2PCH2)2C6H3

Reaction of cis-1,4-dichlorobut-2-ene with dicyclohexylphosphine in the presence of KI in acetone produces [cis-Cy2PHCH2CHCHCH2PHCy2]I2, which is converted to cis-Cy2PCH2CHCHCH2PCy2 on treatment with NaOH. Reactions of cis-Cy2PCH2CHCHCH2PCy2 with MHCl(CO)(PPh3)3 (M=Ru, Os) yield MHCl(CO)(PPh3)(Cy2PCH2CHCHCH2PCy2). The ruthenium complex RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2) is obtained by refluxing RuHCl(CO)(PPh3)(Cy2PCH2CHCHCH2PCy2) in methanol–CH2Cl2. Reaction of RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2) with H2 in the presence of NaBPh4 produces RuHCl(CO)(PPh3)(Cy2P(CH2)4PCy2). Reaction of OsCl(PPh3)(2,6-(Ph2PCH2)2C6H3) with H2 produces OsCl(H⋯H)(PPh3)(2,6-(Ph2PCH2)2C6H3) which contains an elongated dihydrogen ligand.