Molecular Rydberg States and Ionization Energy Studied by Two‐Photon Resonant Ionization Spectroscopy

Abstract

In this ar ti cle, I will re view the ex cited va lence/Rydberg states and ion iza tion en er gies of vi nyl chlo ride, propyne, and allyl rad i cal that we have ex am ined re cently in our lab o ra tory by 2+1 res o nance en hanced multiphoton ion iza tion (REMPI) spec tros copy. In these stud ies, we have em pha sized spec tro scopic in ves ti gations from the first ex cited elec tronic states to the first ion iza tion en er gies of the mol ecules and rad i cals of inter est. In spec tro scopic anal y sis, suc cess ful elec tronic iden ti fi ca tions have been fa cil i tated with the o ret i cal (ab in itio and den sity func tional) cal cu la tions. In par tic u lar, we have ap plied cal cu lated Franck-Condon factors to as sist vi bra tional as sign ment for ex per i men tal vibronic spec tra. The spec tro scopic stud ies of these polyatomic ex cited va lence/Rydberg states help us to il lu mi nate the photodissociation path ways and to man ifest the com pli cated chem i cal-reaction mech a nisms due to the multi-dimensionality in polyatomic mo lec u lar po ten tial en ergy sur faces. 704

Rydberg states and Molecular Photo- Absorption Spectrum of Vinyl Chloride

“…(4). The spectrum feature a large number of fine structure, these structure have been tentatively assigned to members of Rydberg series converging to the ionization energy ( 9.99 eV ) as in table ( 1 ), using equation ( 1) .…”

“…The spectroscopic study of Rydberg states (illustrated in fig. (5)) helps us to illuminate the photo dissociation path ways and to manifest the complicated chemical-reaction mechanisms due to the multidimensionality in polyatomic molecular potential energy surfaces (1).…”

“…Research in the area of molecular excited electronic states covers a broad field of endeavour, touching as it does many aspects in spectroscopy, dynamics/kinetics, photo-dissociation, and chemical reactions (1). Vinyl Chloride is a highly volatile molecule that exists as a gas at Standard Temperature and Pressure; for this reason, occupational exposure to Vinyl Chloride Molecule (VCM) occurs primarily through inhalation.…”