New {RuNO} Polyoxometalate [PW11O39RuII(NO)]4-: Synthesis and Reactivity

New Ru-containing polyoxometalate [PW11O39RuII(NO)]4- (14-) was obtained in high yield by reaction of [Ru(NO)Cl5]2- with [PW11O39]7- and characterized by multinuclear NMR, cyclic voltammetry, IR spectroscopy, and electrospray ionization mass spectrometry (ESI-MS). The intrinsic reactivity of the {RuNO} site in 14- toward various reagents has been studied using a versatile and simple ESI tandem mass spectrometric methodology for identification of the L attached at the Ru site; this approach relies on the preferential liberation of the L ligands attached at the Ru sites upon mass-selecting desired intermediates and subsequent promotion of their fragmentation. Reactions with both hydrazine and hydroxylamine lead to elimination of the nitroso group and quantitative formation of [PW11O39RuIII(H2O)]4- (24-) in aqueous solution. In the reaction with hydroxylamine, an intermediate with coordinated dinitrogen has been detected. An easy access to the NH3-coordinated [PW11O39RuNH3]4- (34-) complex was achieved upon ...