Trichlorostannyl complexes of Ruthenium(II): Synthesis, structure, reactivity and computational studies

Abstract Trichlorostannyl complexes [Ru(SnCl 3 ) (Cp')L] ( 2a-c ) were prepared by treatment of optically active half-sandwich chlorocomplexes [RuCl(Cp')L] ( 1a-c ) with an excess of SnCl 2 .2H 2 O in ethanol. Treatment of trichlorostannyl complexes 2a-c with NaBH 4 afforded trihydridostannyl derivatives [Ru(SnH 3 ) (Cp')L] ( 3a - c) in moderated yields. Treatment of 2a-c with MgBrMe gave the trimethylstannyl complexes Ru(SnMe 3 ) (Cp')L ( 4a - c) . Alkynylstannyl derivatives [Ru{Sn(C≡CPh) 3 }(Cp')L] ( 5a-c) were prepared by treatment of trichlorostannyl compounds 2a-c with an excess of LiC≡CPh in thf. All the complexes present optical activity. The complexes were characterized spectroscopically and by X-ray crystal structure determination of [RuCl(η 5 -C 5 Me 5 )L] ( 1b) , [Ru(SnCl 3 ) (η 5 -C 5 Me 5 )L] ( 2b) , and [Ru(SnCl 3 ) (η 5 -C 9 H 7 )L] ( 2c) . The influence of different ligands on the Ru P interaction in several complexes 1a-c , 2a-c and 3a-c was evaluated by DFT calculations. These calculations indicate that [SnCl 3 ] - has a stronger stabilization effect than [Cl] - and the same occurs between C 9 H 7 and C 5 Me 5 . These relative stabilities combined with the distortion energies of the fragments produce a stabilizing effect in the Ru P bonds of complex 2c that is twice as strong as in the 1b complex.