Search

Halogen complexes of ruthenium cyclopentadienyl [CpRu(PTA) 2 X]; [CpRu(PTA)(PPh 3 )X]; [CpRu(PPh 3 ) 2 Cl], and [CpRu(mPTA)(PPh 3 )X] + (Cp = C 5 H 5 ; PTA = l,3,5-triaza-7-phosphaadamantane; mPTA + = [1-methyl-1,3,5-triaza-7-phosphaadamantane] + ; X = Cl - , I - ) were investigated by electrospray mass spectrometry (ESI-MS), in flow-cell cyclic voltammetry, by microelectrodes, and by combined online electrochemistry and electrospray mass spectrometry (EC/ESI-MS) in dimethyl formamide solution. Coordination changes and the structures of the initial compounds and the products of the electro-oxidation of the Ru(II) complexes were traced by in situ EC/MS n experiments which revealed their fragmentation pathways. ESI-MS collision-induced dissociation fragmentations of the initial reactants and the oxidation products were explained by soft acid-hard base considerations taking into account the different nature of Ru(II)-Ru(IV) centers. The electrochemical studies show that it is possible to tune the formal potentials for the oxidation of [CpRuL 2 X] complexes by over 300 mV by proper selection of the ligands. The increase of the redox potential by the different ligands follows the order PTA < PPh 3 < mPTA + . We demonstrate a similarity between the propensity of the ligand to fragment out in the gas phase and its relationship to the formal potential of the complex.

Eight novel perhydrates Ph4X+Hal−·nH2O2 (X = P, As; Hal = Cl, Br; n = 0.98–1.90) were prepared and their structures were determined by X-ray crystallography. All the structures are formed by parallel infinite zigzag chains of Ph4X+ cations and hydrogen-bonded anionic chains [(H2O2)x(Hal−)y]∞ (x, y = 1, 2). Hydrogen peroxide is partially substituted by admixed water molecules. Some of the studied perhydrates were found to be isostructural with the related hydrates Ph4X+Hal−·nH2O.