Related Experiment Video
Updated: Aug 15, 2026

Measurements of Long-range Electronic Correlations During Femtosecond Diffraction Experiments Performed on Nanocrystals of Buckminsterfullerene
Published on: August 22, 2017
Spectral broadening and diffusion by torsional motion in biphenyl
Wichard J D Beenken1, Hans Lischka
1Department of Theoretical Physics I, Technische Universität Ilmenau, Postfach 100565, 98684 Ilmenau, Germany. wichard.beenken@tu-ilmenau.de
Abstract:
We have studied biphenyl by time-dependent density-functional theory. In particular, we have analyzed the dependence of singlet excitation energies and transition dipoles on the torsional angle between the phenyl groups. The torsional spectrum has been computed quantum mechanically as well as semiclassically in order to understand how this influences the broadening of absorption and luminescence spectra. Our results are in best agreement with supersonic jet spectroscopy data, but also fit astonishingly well to spectra of biphenyl in condensed phase. Furthermore, we compare the torsional and vibrational relaxation and discuss qualitatively the general consequences for poly-para-phenylenes and related conjugated polymers as poly-thiophenes, considering, in particular, how side chains and solvents may affect the optical spectra.
More Related Videos
07:19Preparation of Extracellular Matrix Protein Fibers for Brillouin Spectroscopy
Published on: September 15, 2016
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
Related Concept Videos
IR Spectrum Peak Broadening: Hydrogen Bonding
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular hydrogen bonding...
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
NMR Spectroscopy of Benzene Derivatives
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
Structure of Benzene: Molecular Orbital Model