The hemilabile behaviour of alkyl diphenylphosphinoacetate ligands promoting the reversible coordination of small molecules on (η6-arene)ruthenium(II) centres

Article abstract of DOI:10.1016/0022-328X(94)88129-4

Complexes <(η⁶-arene)<η¹-Ph2PCH2C=O)OR>RuCl2> have been prepared.Easy methanolysis and hydrolysis of the ester function occur when R=t-Bu.When R=Me, the stability of the ester function allows the synthesis of the stable salts <(η⁶-arene)<η²-Ph2PCH2C(=O)OMe>RuCl>X (X=PF6 or BF4).Preparation of <(η⁶-arene)(L)<η¹-Ph2PCH2C(=O)OMe>RuCl>⁺ (L=Me2S, MeC<*>N or t-BuC<*>N) from η¹-P- and η²-(P,O)-methyl phosphinoacetate derivatives has been studied and the strength of both the L and ester ruthenium coordinative bonds compared.The reactivity of these functional phosphine complexes differs markedly from that of the homologous compounds <(η⁶-arene)(PMe3)RuCl2>,<(η⁶-arene)RuCl2> and <(η⁶-arene)<η²-Ph2PC(R)=C(R')O>RuCl.Competitive and reversible coordination of dimethylsulfide and nitriles or of the ester function is observed and a change in the arene produces selectivity in the coordination of dimethylsulfide and nitriles.Key words: Ruthenium; Iron; Phosphine; Arene