Electronic Spectroscopy in the Gas Phase

Abstract

A frequency‐doubled continuous wave (CW) ring dye laser, operating in the ultraviolet (UV), has been combined with a molecular beam machine and rapid data acquisition methods to obtain the electronic spectra of several large polyatomic molecules and their weakly bound complexes at unparalleled spectral resolution, approaching one part in 10 9 . Thus revealed for the first time are the underlying molecular eigenstates of isolated molecules, which provide unique information about their structures and dynamical behavior in both ground and excited electronic states. Light‐induced changes in the electronic charge distributions of different electronic states, with or without the attached solvent molecules, are revealed by studies of these spectra in applied electric fields (the Stark effect). Potential applications of the method to small biological molecules are discussed.

Demodulation of multimodulation artifacts in Fourier-transform infrared spectroscopy

“…Since the pioneering work of Jacquinot and Fellgett [1] in the early 1950s, Michelson's interferometric absorption spectroscopy became a routine tool. With the advent of computers and the algorithmic developments of the fast Fourier transform (FFT) by Cooley and Tukey in 1965 [2], FT spectroscopy increased its applicability to spectral ranges from lower energy (microwave [3], nuclear magnetic resonance [4]) to higher energy (UV/VIS [5,6]).…”