Bimetallic ruthenium–tin chemistry: Synthesis and molecular structure of arene ruthenium complexes containing trichlorostannyl ligands

Abstract

A series of neutral, anionic and cationic arene ruthenium complexes containing the trichlorostannyl ligand have been synthesised from SnCl 2 and the corresponding arene ruthenium dichloride dimers [(η 6-arene)Ru(μ 2-Cl)Cl] 2 (arene = C 6H 6, Pr i C 6H 4Me). While the reaction with triphenylphosphine and stannous chloride only gives the neutral mono(trichlorostannyl) complexes [(η 6-C 6H 6)Ru(PPh 3)(SnCl 3)Cl] ( 1) and [(η 6-Pr i C 6H 4Me)Ru(PPh 3)(SnCl 3)Cl] ( 2), the neutral di(trichlorostannyl) complex [(η 6-Pr i C 6H 4Me)Ru(NCPh)(SnCl 3) 2] ( 3) could be obtained for the para-cymene derivative with benzonitrile as additional ligand. By contrast, the analogous reaction with the benzene derivative leads to a salt composed of the cationic mono(trichlorostannyl) complex [(η 6-C 6H 6)Ru(NCPh) 2(SnCl 3)] + ( 5) and of the anionic tris(trichlorostannyl) complex [(η 6-C 6H 6)Ru(SnCl 3) 3] − ( 6). On the other hand, [(η 6-Pr i C 6H 4Me)Ru(μ 2-Cl)Cl] 2 reacts with SnCl 2 and hexamethylenetetramine hydrochloride or 18-crown-6 to give the anionic di(trichlorostannyl) complex [(η 6-Pr i C 6H 4Me)Ru(SnCl 3) 2Cl] − ( 4), isolated as the hexamethylenetetrammonium salt or the chloro-tin 18-crown-6 salt. The single-crystal X-ray structure analyses of 1, 2, [(CH 2) 6N 4H][ 4], [(18-crown-6)SnCl][ 4] and [ 5][ 6] reveal for all complexes a pseudo-tetrahedral piano-stool geometry with ruthenium–tin bonds ranging from 2.56 (anionic complexes) to 2.60 Å (cationic complex).