Dissociation dynamics of energy selected propanol ions from a {sigma}-type ion structure
- Univ. of North Carolina, Chapel Hill, NC (United States)
The dissociation rates of energy selected propanol ions and partially deuterated propanol ions have been investigated by photoelectron photoion coincidence. Cold CH{sub 3}CH{sub 2}CH{sub 2}OH and CD{sub 3}CH{sub 2}CH{sub 2}OH samples were introduced into the photoionization region of a time-of-flight mass spectrometer through a skimmed molecular beam. The ions dissociated via the loss of H and H{sub 2}O, the latter dominating near threshold. These rates ranged from 10{sup 5} to 10{sup 7} s{sup {minus}1} near the dissociation onset. Slow dissociation from the ion-dipole complex C{sub 3}H{sub 6}{sup +}{hor_ellipsis}H{sub 2}O is iniconsistent with the simultaneous occurrence of metastable H loss and the lack of hydrogen scrambling prior to dissociation. However, the dissociation rates for H{sub 2}O loss and H loss are described well by assuming statistical dissociation from the {sigma}-type electronic ground state of the molecular ion, which lies 0.5 eV below the reported ionization onset. This mechanism is consistent with the simultaneous occurrence of metastable H loss and lack of hydrogen scrambling at low energies. Hydrogen tunneling does not play a role in either loss channel. 23 refs., 4 figs., 1 tab.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 273591
- Journal Information:
- Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 14 Vol. 96; ISSN JPCHAX; ISSN 0022-3654
- Country of Publication:
- United States
- Language:
- English
Similar Records
Isomerization and dissociation in competition. The two-component decay rates of energy-selected trimethyl borate ions
Ab initio molecular orbital study of C{sub 3}H{sub 8}O{sup +} ions