Energy flow and fragmentation dynamics of n,n-dimethylisopropylamine.
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 alpha 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.
Gosselin
Jaimie L
JL
Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
Minitti
Michael P
MP
Rudakov
Fedor M
FM
Sølling
Theis I
TI
Weber
Peter M
PM
D013058:Mass Spectrometry; D011412:Propanolamines / Q000737:chemistry*; D011789:Quantum Theory
D011412:Propanolamines; C031822:N,N-dimethylaminoisopropanol