GAS-PHASE REACTIVITY OF SULFUR IONS WITH AMMONIA

The gas-phase reactions of sulphur cluster ions, cations S(n)+ (n = 1, ..., 8) and anions S(n)- (n = 2, ..., 6) with NH3 have been studied b y means of a Fourier transform ion cyclotron resonance (FT-ICR) mass s pectrometer. Relative and absolute reaction rate constants as well as reaction efficiencies have been determined. The S4+ cation has by the far highest reactivity with all other sulphur cations being significan tly less reactive. Besides some fragmentation, no reactivity of the an ions was found. Structural conclusions are made based on the present e xperiments, on previous extensive ab initio calculations, and on compl ementary experiments.