Georg Hvistendahl

Ion/molecule reactions in a mixture of Ar and H2: high pressure mass spectrometry and quantum chemical calculations

Abstract The ion/molecule reactions taking place as the result of electron impact on a 100:1 mixture of Ar and H2 have been stidied by pulsed electron beam high pressure mass spectrometry. It is shown that ArH+ hydrogen bonds to Ar to give (ArHAr)+ and to H2 to give ArH+3. The bond to H2 is stronger by 20 ± 13 kJ mol−1. The experimental data agree well with results from high level ab initio quantum chemical calculation.

Isotope effects on kinetic energy release: elimination of CH4 from [CH3CHOH]+ and [CH2OCH3]+

Abstract By comparing experimental results (isotope substitution and kinetic energy release measurements) with the results of calculations (quantum chemistry and application of the “dynamic theory”), the mechanisms of the two title reactions have been probed.

An MC SCF study of the reaction C3H7+ → C3H5+ + H2

Abstract Ab initio molecular-orbital methods have been used to examine three possible reaction mechanisms for the reaction C 3 H 7 + → C 3 H 5 + + H 2 . Calculations have been performed for 1,3-elimination from the 2-propyl cation (I), 1,2-elimination from the 1-propyl cation (II) and 1,1-elimination from corner-protonated cyclopropane (III). The calculated activation-energy parameters for mechanism II show the best agreement with the experimental values.

Activation of H-H and C-H Bonds with Complexed Iron Ions in the Gas Phase and in Solution

Publisher Summary Naked as well as complexed metal ions may provide interesting model systems for catalytic systems involved in natural gas conversion processes. During the last 20 years it has been shown that many transition metal ions activate the C-H and C-C bonds of hydrocarbons in the gas phase. Reactions between most transition metal ions and hydrocarbons larger than ethane produce metal ion alkene complexes as the result of elimination of either H 2 or a hydrocarbon. Alkene loss is also commonly observed. Although naked metal ions have been studied extensively much less is known about reactions of complexed metal ions with hydrocarbons. This chapter presents results from studies of reactions of the coordinatively unsaturated 16-electron systems HFe(CO) 4 + and Fp + (Fp = η 5 -C 5 H 5 (CO) 2 Fe ). Reactions of alkyl cations with Fe(CO) 5 and FpCH 3 are also discussed.