Boron chlorination on a Cp*Rh-coordinated bis(2-mercapto-l-arylimidazolyl)borate [H_2B(tim~(Ar))_2]~-: [Cp*Rh{k~2-S S'-ClHB(tim~(Ar))_2][BF_4]?H_2O

摘要

Two rhodium(III) complexes [Cp*Rh{k~2-S,S'-ClHB(tim~(Ar))_2}Cl] and [Cp*Rh){k~3-H,S,S'-ClHB(tim~(Ar))_2}][BF_4]-H_2O with the terminal B-Cl bonds were isolated by reaction of boron-chlorination and structurally characterized by X-ray crystallography.Interaction of [Cp*Rh(u-Cl)Cl]_2 with two equiv. of Na[H_2B(tim~(Ar))_2] (tim~(Ar))= 1 -(4-chloro-phenyl)-imidazole-2-thione) in THF afforded [Cp*Rh{K~2-S,S'-H_2B(tim~(Ar))_2}Cl] (1). Treatment of 1 with AgBF_4 in THF gave [Cp*Rh{k~3-H,S,S'-H_2B(tim~(Ar))_2}][BF_4] (2) with an agostic B-H-Rh bond, whereas 1 in a stirring CHC13 solution led to isolation of [Cp*Rh{k~2-S,S'-ClHB(tim~(Ar))_2}Cl] (3) with a B-Cl bond. Similarly, treatment of 3 with AgBF4 in THF gave the cationic complex [Cp*Rh{k~3-H,S,S'-ClHB(tim~(Ar))_2}][BF_4]?H_2O (4-H_2O) with both agostic B-H-Rh and terminal B-Cl bonds, isolated from the solution of 2 in CHCl_3. All complexes were spectroscopically characterized and structures of 3 and 4?H_2O have been established by X-ray crystallography.