Gas-phase reactions of SiH(n)+ (n = 1,2) with NF3: a computational investigation on the detailed mechanistic aspects.

The mechanism of the gas-phase reactions of SiH(n)(+) (n = 1,2) with NF(3) were investigated by ab initio calculations at the MP2 and CAS-MCSCF level of theory. In the reaction of SiH(+), the kinetically relevant intermediates are the two isomeric forms of fluorine-coordinated intermediate HSi-F-NF(2)(+). These species arise from the exoergic attack of SiH(+) to one of the F atoms of NF(3) and undergo two competitive processes, namely an isomerization and subsequent dissociation into SiF(+) + HNF(2) , and a singlet-triplet crossing so to form the spin-forbidden products HSiF(+) + NF(2).

Gas-phase chemistry of ionized and protonated GeF4: a joint experimental and theoretical study.

The gas-phase ion chemistry of GeF(4) and of its mixtures with water, ammonia and hydrocarbons was investigated by ion trap mass spectrometry (ITMS) and ab initio calculations. Under ITMS conditions, the only fragment detected from ionized GeF(4) is GeF(3)(+). This cation is a strong Lewis acid, able to react with H(2)O, NH(3) and the unsaturated C(2)H(2), C(2)H(4) and C(6)H(6) by addition-HF elimination reactions to form F(2)Ge(XH)(+), FGe(XH)(2)(+), Ge(XH)(3)(+) (X = OH or NH(2)), F(2)GeC(2)H(+), F(2)GeC(2)H(3)(+) and F(2)GeC(6)H(5)(+).