Preparation and Reactivity of Germyl Complexes of Ruthenium and Osmium Stabilised by Cyclopentadienyl, Indenyl and Tris(pyrazolyl)borate Fragments

Half-sandwich trichlorogermyl complexes Ru(GeCl3) (η5-C5H5)(PPh3)L (1) and Ru(GeCl3)(η5-C9H7)(PPh 3)L (2) [L=P(OMe)3 (a), P(OEt)3 (b) and PPh(OEt)2 (c)] were prepared by allowing chloro compounds RuCl(η5-C5H5)(PPh3)L and RuCl(η5-C9H7)(PPh3)L to react with an excess of GeCl2 · dioxane in ethanol. Treatment of trichlorogermyl complexes 1 and 2 with LiAlH4 in THF yielded trihydridogermyl derivatives Ru(GeH3)(η5-C 5H5)(PPh3)L (3) and Ru(GeH3) (η5-C9H7)(PPh3)L (4). Instead, reaction of trichlorogermyl complexes 1 and 2 with NaBH4 in ethanol afforded triethoxygermyl complexes Ru[Ge(OEt)3](η5- C5H5)(PPh3)L (5) and Ru[Ge(OEt) 3](η5-C9H7)(PPh3)L (6). Trichlorogermyl complexes with the tris(pyrazolyl) borate ligand M(GeCl3)(Tp)(PPh3)L [M=Ru (7), Os (10)] were prepared by reacting chloro compounds MCl(Tp)(PPh3)L with an excess of GeCl 2 · dioxane. Depending on metal centre, nature of phosphite and experimental conditions, the reaction of trichlorogermyl complexes 7 and 10 with LiAlH4 or NaBH4 afforded trihydridogermyl M(GeH 3)(Tp)(PPh3)L (8, 12) and triethoxygermyl derivatives M [Ge(OEt)3](Tp)(PPh3)L (9, 11). The complexes were characterised by IR and multinuclear NMR spectroscopy and by X-ray crystal structure determination of 3a. © 2013 Elsevier B.V. All rights reserved.

Half-sandwich trichlorogermyl complexes Ru(GeCl3)(h5 -C5H5)(PPh3)L (1) and Ru(GeCl3)(h5 -C9H7)(PPh3)L (2) [L ¼ P(OMe)3 (a), P(OEt)3 (b) and PPh(OEt)2 (c)] were prepared by allowing chloro compounds RuCl(h5 -C5H5)(PPh3)L and RuCl(h5 -C9H7)(PPh3)L to react with an excess of GeCl2$dioxane in ethanol. Treatment of trichlorogermyl complexes 1 and 2 with LiAlH4 in THF yielded trihydridogermyl derivatives Ru(GeH3)(h5 -C5H5)(PPh3)L (3) and Ru(GeH3)(h5 -C9H7)(PPh3)L (4). Instead, reaction of trichlorogermyl complexes 1 and 2 with NaBH4 in ethanol afforded triethoxygermyl complexes Ru[Ge(OEt)3](h5 - C5H5)(PPh3)L (5) and Ru[Ge(OEt)3](h5 -C9H7)(PPh3)L (6). Trichlorogermyl complexes with the tris(pyrazolyl)borate ligand M(GeCl3)(Tp)(PPh3)L [M ¼ Ru (7), Os (10)] were prepared by reacting chloro compounds MCl(Tp)(PPh3)L with an excess of GeCl2$dioxane. Depending on metal centre, nature of phosphite and experimental conditions, the reaction of trichlorogermyl complexes 7 and 10 with LiAlH4 or NaBH4 afforded trihydridogermyl M(GeH3)(Tp)(PPh3)L (8, 12) and triethoxygermyl derivatives M [Ge(OEt)3](Tp)(PPh3)L (9, 11). The complexes were characterised by IR and multinuclear NMR spectroscopy and by X-ray crystal structure determination of 3a.