High Resolution Electronic Spectroscopy of Vibrationally Hot Bands of Benzimidazole

Abstract

Rotationally resolved electronic spectra of seven vibrationally excited bands in the electronic spectrum of benzimidazole have been measured and analyzed. From the vibrational contributions to the rotational constants, an assignment of the hot bands could be made on the basis of anharmonic corrections to the harmonic normal modes and by using the information contained in the Duschinsky matrix calculated by second order coupled cluster (CC2) theory. Fluorescence emission and (hot) absorption spectra of benzimidazole from Jalviste and Treshchalov [Chem. Phys. 1993, 172, 325] have been simulated using Franck-Condon integrals obtained from CC2 optimized geometries and Hessians.

Statistical method of generating envelopes of the electronic hot bands

“…Recently, high‐precision experimental techniques have been applied to observe the hot bands for different molecules . Theoretically, single lines in hot bands may be analyzed using advanced quantum chemical calculations such as coupled‐clusters theory …”

“…Recently, high-precision experimental techniques have been applied to observe the hot bands for different molecules. [1][2][3][4][5][6][7][8] Theoretically, single lines in hot bands may be analyzed using advanced quantum chemical calculations such as coupledclusters theory. [9] Some basic information about the shape of a spectrum, in particular of the hot bands, is given by the envelope of the spectrum.…”