PHOTODISSOCIATION DYNAMICS OF SPATIALLY ALIGNED MOLECULES BY TIME-RESOLVED ELECTRON DIFFRACTION

Abstract

The anisotropic ensembles of laser-excited molecules can be formed, for example, under the action of fs pulses of polarized laser radiation. It was theoretically predicted that the electron diffraction pattern from aligned molecules in the gas phase allows determining not only internuclear distances but also valence angles that is 3D molecular structure. In the current article, we propose the basic elements of the theory that can be employed for analyze of time-resolved electron diffraction (TRED) data obtained from oriented/aligned laser-excited molecules. This formalism is applicable to dissociative processes and to nuclear dynamics studies of photo dissociation studies. The theory is illustrated by modeling the diffraction intensities of photo generated dissociation of ICN molecules. The time-dependent intensities of the molecular scattering and the corresponding radial distribution functions of the internuclear distances at the processes of the photo dissociation of ICN were calculated.Based on model calculations presented in this article we conclude that TRED method provides the principal possibility of study of coherent dissociation dynamics for real scale of time which is essentially less than the electron pulse duration of 300 fs, which is achieved at present in a number of TRED experiments. The results obtained were compared with our previous modeling studies of randomly oriented and diatomic aligned molecular ensembles.Forcitation:Schafer L., Ischenko A.A., Zhabanov Yu.A., Otlyotov A.A., Girichev G.V. Photodissociation dynamics of spatially alig-ned molecules by time-resolved electron diffraction. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 3. P. 4-14.