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Updated: Oct 10, 2025

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
Kinetic Mass Spectrometric Investigation of the Ion-Molecule Reactions Occurring in C4 and C5 Alkanes Following
L Wayne Sieck1, S K Searles1, P Ausloos1
1Institute for Materials Research, National Bureau of Standards, Washington, D.C. 20234.
Abstract:
The photoionization of C4 and C5 alkanes has been investigated at 106.7 and 104.8 nm in a mass spectrometer specifically designed for the investigation of ion-molecule reactions occurring at thermal kinetic energies. Absolute rate constants are reported for the reactions of various fragment ions with the corresponding parent molecule. The rate constants found for reactions of ions with i-C4H10, n-C4H10, i-C5H12, and n-C5H12 were found to be 3.3, 4.4, 4.7, and 5.2 × 10-10 cm3/molecule-second respectively. The ions were also found to be highly reactive, exhibiting rate constants of 3.6 and 3.8 × 10-10 cm3/molecule-second in reactions with i-C5H12 and n-C5H12. The rate constants for reaction of with i-C4H10, n-C4H10, i-C5H12, and n-C5H12 were found to be 4.9, 4.9, 7.6, and 7.9 × 10-10 cm3/molecule-second, respectively. Butene ions are less reactive by an order of magnitude. The results are compared with complementary data derived from electron impact experiments, and the relationship between the structure and reactivity of the various ions is discussed.
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