title: Novel Unsymmetrical Ru(III) and Mixed-valence Ru(III)/Ru(II) Dinuclear Compounds Related to the Antimetastatic Ru(III) Drug NAMI-A.
abstract: In this paper we report the stepwise preparation and the characterization of new unsymmetrical monoanionic Ru(III) dinuclear compounds, [NH(4)][{trans-RuCl(4)(Me(2)SO-S)}(mu-L){mer-RuCl(3)(Me(2)SO-S)(Me(2)SO-O)}] (L = pyz (1), pym (2)). By a similar synthetic approach we also prepared new mixed-valence Ru(III)/Ru(II) dinuclear compounds of formula [NH(4)][{trans-RuCl(4)(Me(2)SO-S)}(mu-pyz){cis,cis,cis-RuCl(2)(Me(2)SO-S)(2)(CO)}] (L = pyrazine (pyz, 3), pyrimidine (pym, 4)). Moreover, we describe the chemical behavior of compounds 1-4 in physiological solution, also after complete reduction (with ascorbic acid) to the corresponding Ru(II)/Ru(II) species. Overall, the chemical behavior of 1 and 2 after reduction resembles that of the corresponding dianionic and neutral dinuclear species, [{trans-RuCl(3)(Me(2)SO-S)}(2)(mu-L)](2-)and [{mer-RuCl(3)(Me(2)SO-S)(Me(2)SO-O)}(2) (mu-L)]. On the other hand, the mixed-valence dinuclear compounds 3 and 4, owing to the great inertness of the cis,cis,cis-RuCl(2)(Me(2)SO-S)(2)(CO)(1/2mu-L) fragment, behave substantially like the mononuclear species [trans-RuCl(4)(Me(2)SO-S)(L)](-) in which the terminally bonded L ligand can be considered as bearing a bulky substituent on the other N atom.
authors.affiliation: Dipartimento di Scienze Chimiche University of Trieste Via L. Giorgieri 1 Trieste 34127 Italy.
authors.forename: B
authors.initials: B
authors.lastname: Serli
authors.forename: E
authors.initials: E
authors.lastname: Iengo
authors.forename: T
authors.initials: T
authors.lastname: Gianferrara
authors.forename: E
authors.initials: E
authors.lastname: Zangrando
authors.forename: E
authors.initials: E
authors.lastname: Alessio