Excited state energetics of aniline-rare-gas van der Waals complexes

Aniline-Nen and aniline-Arn (n = 1 and 2) complexes were synthesized in continuous and in pulsed supersonic expansions and interrogated by laser-induced fluorescence. Information on the formation kinetics and excited state energetics was obtained

Perspectives of synchrotron radiation applications to molecular dynamics and photochemistry

A general review is given of present and future applications of synchrotron radiation to the study of molecular dynamics and photochemistry. The following are discussed : 1) Intramolecular and intermolecular relaxation processes in gas and condensed phases ; 2) Time and energy resolved observables regarding molecular relaxation ; Coherent optical effects ; 3) Relevant excitation energy regions for the study of different aspects of molecular dynamics ; 4) Excitation sources ; Comparison between synchrotron, laser and plasma sources ; 5) Some experimental systems and modern detection methods ; 6) Further applications of high energy molecular dynamics ; 7) Special constraints and benefits of working with synchrotron radiation

Cooperative exciton states in molecular crystals

In this paper we calculate the transition probability for excitation of double-exciton states in absorption and emission processes in molecular crystals. The formalism is based on the tight-binding approximation, treating the intermolecular electrostatic and exchange interactions and the interaction with the radiation field by perturbation theory. It is found that: (1) A major contribution to the transition probability for cooperative excitation to electronic states arises from intermolecular Coulomb interactions, while the contribution of intermolecular electron-exchange interactions is relatively small. (2) Contributions to the transition probability from high-order- transition multipole interactions are of considerable importance. (3) Approximate selection rules for cooperative electronic excitation imply that for one component the initial and final states are of the same parity, while for the second component the transition is symmetry allowed. (4) Theoretical evidence is obtained for the appearance of double-excitation bands in the infrared spectra of solids in the overtone region. (5) A major contribution to the intensity of the double-vibrational-exciton states arises from an intermolecular Fermi resonance effect. (6) The direct detection of the radiative annihilation of a double-exciton state is not likely to be experimentally feasible.SCOPUS: ar.jinfo:eu-repo/semantics/publishe