Synthesis and structure of the dinuclear chloro-rhodium p-complexes with vinylsilanes Paulina Bl  az ˙ejewska-Chadyniak, Maciej Kubicki, Hieronim Maciejewski, Bogdan Marciniec * Department of Organometallic Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, Poznan ´ 60-780, Poland Received 17 August 2002; accepted 13 December 2002 Dedicated to Professor Pierre Braunstein in recognition of his great contribution to inorganic and organometallic chemistry Abstract Reaction of the Cramer’s complex [{Rh(C 2 H 4 ) 2 (m-Cl)} 2 ] with the appropriate vinylsilane molecules yields, by displacement of the ethylene ligands, the complexes [{Rh(h 2 -CH 2 /CHSiR 3 ) 2 (m-Cl)} 2 ] (where R 3 /Me 3 (1), Me 2 Ph (2), MePh 2 (3), Ph 3 (4), Me 2 (OSiMe 3 )(5)). The structures of 1, 2 and 3 complexes have been determined crystalographically. There are the first crystal structures of dinuclear rhodium(I) complexes with monovinylsilanes. All complexes have been characterised by multinuclear NMR spectroscopy. # 2003 Elsevier Science B.V. All rights reserved. Keywords: Rhodium(I); Vinylsilane; p-Complexes 1. Introduction Transition metal  /alkene p-complexes have attracted much attention, largely due to their prominent role in catalysis and also due to their high lability, as starting materials for the synthesis of a wide range of new complexes. A lot of examples of complexes with p- bonded ligands are known [1] but those containing vinyl derivatives of organosilicon compounds are uncommon. The interest in the chemistry of transition metal olefin complexes containing vinyl derivatives of organosilicon compounds as p-ligands is fully justified not only by the particular nature of the bond between vinylsilicon derivatives and transition metals, but mainly by the possible application of this kind of complexes to catalysis of hydrosilylation processes [2  /6]. Among platinum compounds used as hydrosilylation catalysts are Pt(0) complexes containing vinyl  /siloxane ligands and an example of them is the Karstedt’s catalyst [7] containing both bridging and chelating divinyl ligands [{Pt(h-CH 2 /CHSiMe 2 ) 2 O} 2 {m-(h-CH 2 /CHSiMe 2 ) 2 O}] [8,9]. Other platinum complexes containing both divi- nyltetramethyldisiloxane [10,11] and vinylsilane [12  /15] have also been synthesised. High catalytic activity of complexes of this kind has stimulated much research aimed at using other transition metal compounds as potential catalysts. By analogy to Karstedt’s catalyst, the complexes of nickel [16] and palladium [17] have been prepared and a few other phosphine  /nickel com- plexes with vinylsiloxane [17  /20], vinylsilane [20,21] and vinylsilazane [22] have also been analysed. There are some examples of rhodium p-complexes with vinylsilicon ligands. Binuclear Rh(I) complexes with divinylsiloxane [{Rh(h-CH 2 /CHSiR 2 ) 2 O(m-Cl)} 2 ] (where R /Me, Ph) were reported by Lappert group [23]. Mononuclear Rh complexes of the type [(acac)Rh(h-CH 2 /CHSiR 3 ) 2 ] or [(acac)Rh{h-(CH 2 / CH) 2 SiR 2 }] with vinylsilane or divinylsilane were synthesised by Fitch [24,25] and a few half-sandwich complexes with divinylsilane, e.g., [(h 5 -C 9 H 7 )Rh{h 4 - (CH 2 /CH) 2 SiMe 2 }] [25] or [Cp*Rh{h-(CH 2 /CH) 2 - SiR 2 }] [26] and divinyl-siloxane or -silazane, e.g., [Cp*Rh{h-(CH 2 /CHSiMe 2 ) 2 X}] (where X /O, NH) [27] were also obtained. * Corresponding author. Fax:  /48-61-8291 508. E-mail address: marcinb@main.amu.edu.pl (B. Marciniec). Inorganica Chimica Acta 350 (2003) 603  /608 www.elsevier.com/locate/ica 0020-1693/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0020-1693(03)00049-5