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T E Dermota

Publications and source records attributed to T E Dermota.

5 recordsLinked to original sources
PubMed2005

Photoinduced ion-pair formation in the (HI)m(H2O)n cluster system.

The temporal behavior of the photoinduced ion-pair formation process in the (HI)m(H2O)n (n=1-6 for m=1 and n=1-4 for m=2) cluster system has been studied via the coupling between the g 3Sigma- Rydberg and V 1Sigma+ valence states. Comparison of the time constants obtained to those measured in previous experiments for the analogous process in HBr-water clusters, along with a detailed analysis of the signal intensity as a function of laser-pulse power, provides new insight into and confirmation of the previously proposed ion-pair formation mechanism.

Journal Article↗
PubMed2005

Excited-state dynamics of (SO2)m clusters.

A study of the excited-state dynamics of (SO2)m clusters following excitation by ultrafast laser pulses in the range of 4.5 eV (coupled 1A2, 1B1 states) and 9 eV (F band) is presented. The findings for the coupled 1A2 and 1B1 states are in good agreement with published computational work on the properties of these coupled states. A mechanism involving charge transfer to solvent is put forward as the source of the excited-state dynamics that follow the excitation of the SO2 F band within (SO2)m+1 clusters with m > 1. The proposed CTTS mechanism is supported by calculations of the energetics of the process and the observed trends in the excited-state lifetimes that correlate very well with the calculated energies.

Journal Article↗
PubMed2005

Ultrafast dynamics of the SO2(H2O)n cluster system.

An investigation of the excited-state dynamics of SO2(H2O)n (n = 1-5) clusters following excitation by ultrafast laser pulses to 4.7 eV (coupled 1A2 and 1B1 states) and 9.3 eV (F band) is presented. The findings for the coupled 1A2 and 1B1 states are in good agreement with published computational work and indicate the division of the initial excited-state population into the double well produced by the coupled states. A photoinduced ion-pair formation process is proposed as a likely source of the observed dynamic behavior following the 9.3 eV excitation. Energetics calculations are also presented that support the ion-pair mechanism. A lack of cluster size dependence in the measured time constants indicate surface solvation of SO2 rather than a cluster structure with the SO2 molecule fully encompassed by water molecules.

Journal Article↗
PubMed2002

Dynamics of hydrogen bromide dissolution in the ground and excited states.

The dissolution of acids is one of the most fundamental solvation processes, and an important issue is the nature of the hydration complex resulting in ion pair formation. We used femtosecond pump-probe spectroscopy to show that five water molecules are necessary for complete dissolution of a hydrogen bromide molecule to form the contact ion pair H+.Br-(H2O)n in the electronic ground state. In smaller mixed clusters (n < 5), the ion pair formation can be photoinduced by electronic excitation.

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