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The multiphoton ionization of (CF3I)nXem mixed clusters formed at the outflow of a mixture of CF3I and Xe from an ultrasonic pulsed nozzle by femtosecond ultraviolet radiation (λ = 266 nm) has been studied. The formation of XeI+ mixed ions and ions in intracluster reactions has been detected. It has been shown that the efficiency of the formation of XeI+ ions significantly depends on the duration of a laser pulse: ultraviolet picosecond radiation is necessary for their formation. The kinetic yield curves of the XeI+ and ions upon ultraviolet multiphoton ionization of (CF3I)nXem mixed clusters have been measured. The characteristic times of their formation determined from these curves are (53 ± 8) ps and (65 ± 6) ps, respectively. [ABSTRACT FROM AUTHOR]

The fragmentation of homogeneous (CFI) clusters (where n ≤ 45 is the average number of molecules in a cluster) in a molecular beam, as well as (CFI) clusters inside of large (Xe) clusters (where m ≥ 100 is the average number of atoms in a cluster) or on their surface, by laser ultraviolet radiation has been studied. It has been found that the indicated three types of (CFI) clusters have different stabilities with respect to fragmentation and strongly different dependences of the fragmentation probability on the energy of ultraviolet radiation. Fragmentation at low energies and the weakest energy dependence of the probability of fragmentation are observed for homogeneous clusters, a stronger dependence is characteristic of (CFI) clusters localized inside (Xe) clusters, and the strongest dependence is observed for (CFI) clusters on the surface of (Xe) clusters. Possible reasons for such a character of the observed dependences have been discussed. [ABSTRACT FROM AUTHOR]

Intracluster reactions that are induced in (CFI) clusters by femtosecond ultraviolet radiation, including the reaction of the formation of the I molecular ion, have been directly observed. It has been shown that there are two channels of the formation of I ions with the characteristic times τ ≈ 1 ps and τ ≈ 7 ps. A model of these reactions has been proposed that is in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

The dynamics of intramolecular vibrational-energy redistribution from an initially excited mode ν1 (the acetylene-type H–C bond) to the other modes of the H–C≡C–Si(CH3)3 molecule was studied experimentally. Probing was performed by spontaneous anti-Stokes Raman scattering. The measured deexcitation time of ν1 was 128±10 ps. © 2004 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

It is found that CF2HCl molecules dissociate under irradiation by high-intensity pulses of femtosecond radiation (λ = 1.8 μm) in the vicinity of resonance with the frequency of overtone vibrational transitions in the C-H bond. It is shown that the dissociation products substantially differ from the products of dissociation of CF2HCl molecules from the ground and excited electronic states under the action of IR and UV nanosecond pulses. [ABSTRACT FROM AUTHOR]