MONONUCLEAR, BINUCLEAR AND TRINUCLEAR BIS(ALLYL) COMPLEXES OF RUTHENIUM(IV) CONTAINING N-DONOR LIGANDS

The ruthenium(IV) bis(allyl) complex [{Ru(eta3:eta3-C10H16)Cl(mu-Cl)}2] (1) reacts with pyrazene to give a binuclear complex, [{Ru(eta3:eta3-C10H16)Cl2}2(mu-N2C4H4)] (2), which exists in two diastereomeric forms of C(i) (meso) and C2 (rac) symmetries. The analogous reaction with 1,3,5-triazine yields a mixture of mono-, bi- and trinuclear complexes, [{Ru(eta3:eta3-C10H16)Cl2}n(N3C3H3)] [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(eta3:eta3-C10H16)Cl2(mu-N2C4H4)RuCl2(eta6-p-MeC6H4CHMe2)] (7b) is also reported. Pretreatment of 1 with Ag[BF4] in acetone generates mono- and dicationic solvate species which readily react with polypyridyl and related ligands to generate the chelate species [Ru(eta3:eta3-C10H16)Cl(L-L)][BF4] [L-L = 2,2'-bipyridyl (11), L-L = 1,10-phenanthroline (12)] and [Ru(eta3:eta3-C10H16)(terpy)][BF4]2 (13) (terpy = 2,2': 6',2"-terpyridine). Complex 11 has been characterized by X-ray crystallography.