Mono-, bi- and trinuclear bis(allyl) complexes of ruthenium(IV) containing N-donor ligands

Abstract

The ruthenium(IV) bis(allyl) complex [{Ru(μ 3 : μ 3-C 10H 16)Cl(μ-Cl)} 2] ( 1) reacts with pyrazene to give a binuclear complex, [{Ru(μ 3 : μ 3-C 10H 16)Cl 2} 2(μ-N 2C 4H 4)] ( 2), which exists in two diastereomeric forms of C i ( meso) and C 2 ( rac) symmetries. The analogous reaction with 1,3,5-triazine yields a mixture of mono-, bi- and trinuclear complexes, [{Ru(μ 3 : μ 3-C 10H 16)Cl 2} n (N 3C 3H 3 [ n = 1 ( 4), n = 2 ( 5), n = 3 (6), which interconvert with one another in chloroform solution at room temperature. Complexes 5 and 6 have been isolated and, like 2, 5 exists as two diastereoisomers. Complex 6, however, possesses four isomeric forms. The class I mixed-valence Ru IV-Ru II pyrazene-bridged complex [(Ru(μ 3 : μ 3-C 10H 16)Cl 2(μ-N 2C 4H 4)RuCl 2(μ 6- p-MeC 6H 4CHMe 2)] 7b) is also reported. Pretreatment of 1 with Ag[BF 4] in acetone generates mono- and dicationic solvate species which readily react with polypyridyl and related ligands to generate the chelate species [Ru(μ 3 : μ 3-C 10H 16)Cl(L-L)[BF 4] [L-L = 2,2′-bipyridyl ( 11), L-L = 1,10-phenanthroline ( 12)] and [Ru(μ 3 : μ 3-C 10H 16)(terpy)][BF 4] 2 ( 13) (terpy = 2,2t' : 6′,2″-terpyridine). Complex 11 has been characterized by X-ray crystallography.