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

Abstract

a b s t r a c t Trichlorostannyl complexes [Ru(SnCl 3 ) (Cp')L] (2a-c) were prepared by treatment of optically active halfsandwich 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(h 5 -C 5 Me 5 )L] (1b), [Ru(SnCl 3 ) (h 5 -C 5 Me 5 )L] (2b), and [Ru(SnCl 3 ) (h 5 -C 9 H 7 )L] (2c). The influence of different ligands on the RueP 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 eC 9 H 7 and eC 5 Me 5 . These relative stabilities combined with the distortion energies of the fragments produce a stabilizing effect in the RueP bonds of complex 2c that is twice as strong as in the 1b complex.