The carbonyl-ruthenium substituted undecatungstosilicate [α-SiW 11O39RuII(CO)]6- (1) was isolated as a caesium salt and successfully characterized by using 183W and 13C NMR, elemental analysis, IR, UV-vis and cyclic voltammetry (CV). Polyanion 1 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, [α-SiW11O39Ru III(CO)]5-. This RuIII(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 [α-SiW 11O39RuIII(H2O)]5- and then the dimeric POM species by condensation. Furthermore, 1 could be converted to the corresponding aqua polyanion by photo-irradiation.
ASJC Scopus subject areas
- Inorganic Chemistry