Energy Flow and Fragmentation Dynamics of N,N-Dimethylisopropylamine

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Vol. 110; no. 12; pp. 4251 - 4255
• Main Authors: Gosselin, Jaimie L., Minitti, Michael P., Rudakov, Fedor M., Sølling, Theis I., Weber, Peter M.
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 30.03.2006
• Subjects: Mass Spectrometry; Propanolamines - chemistry; Quantum Theory
• DOI: 10.1021/jp0574706
• ISSN: 1089-5639

The energy flow and fragmentation dynamics of N,N-dimethylisopropylamine (DMIPA) upon excitation to the 3p Rydberg states has been investigated with use of time-resolved photoelectron and mass spectrometry. The 3p states are short-lived, with a lifetime of 701 ± 45 fs. From the time dependence of the photoelectron spectra, we infer that the primary reaction channel leads to the 3s level, which itself decays to the ground state with a decay time of 87.9 ± 10.2 ps. The mass spectrum reveals fragmentation with cleavage at the α C−C bond, indicating that the energy deposited in vibrations during the internal conversion from 3p to 3s exceeds the bond energy. A thorough examination of the binding energies and temporal dynamics of the Rydberg states, as well as a comparison to the related fragmentation of N,N-dimethyl-2-butanamine (DM2BA), suggests that the fragments are formed on the ion surfaces, i.e., after ionization and on a time scale much slower than the fluorescence decay from 3s to the ground state.