title: Carbonyl-ruthenium substituted alpha-Keggin-tungstosilicate, [alpha-SiW(11)O(39)Ru(II)(CO)](6-): synthesis, structure, redox studies and reactivity.
abstract: The carbonyl-ruthenium substituted undecatungstosilicate [alpha-SiW(11)O(39)Ru(II)(CO)](6-) () was isolated as a caesium salt and successfully characterized by using (183)W and (13)C NMR, elemental analysis, IR, UV-vis and cyclic voltammetry (CV). Polyanion represents the first example of a metal-carbonyl moiety being fully incorporated into the polyoxometalate (POM). As a result, the Ru(CO) moiety became redox active and was reversibly oxidized to the one-electron ruthenium(iii) derivative, [alpha-SiW(11)O(39)Ru(III)(CO)](5-). This Ru(III)(CO) moiety was unexpectedly stable in aqueous solution compared to the organo-ruthenium carbonyl derivatives and could be detected by using UV-vis and in situ IR coupled with electrolysis. The oxidized ruthenium(iii) derivative slowly released CO in aqueous solution, resulting in the aqua species [alpha-SiW(11)O(39)Ru(III)(H(2)O)](5-) and then the dimeric POM species by condensation. Furthermore, could be converted to the corresponding aqua polyanion by photo-irradiation.
authors.affiliation: Catalysis Research Center, Hokkaido University, N-21, W-10, 001-0021, Sapporo, Japan. sadakane@cat.hokudai.ac.jp
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sadakane
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Iimuro
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tsukuma
authors.forename: Bassem S
authors.initials: BS
authors.lastname: Bassil
authors.forename: Michael H
authors.initials: MH
authors.lastname: Dickman
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kortz
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shen
authors.initials: S
authors.lastname: Ye
authors.forename: Wataru
authors.initials: W
authors.lastname: Ueda