Excited states of trans-stilbene and 1,4-diphenylbutadiene. Near and vacuum UV polarization spectroscopy

The UV absorbance spectra of trans-stilbene ((E)-1,2-diphenylethene, DPE) and (E,E')-1,4-diphenyl-1,3-butadiene (DPB) are investigated by Synchrotron Radiation Linear Dichroism (SRLD) spectroscopy using stretched polyethylene as an anisotropic solvent. The investigation covers the range 58,000-25,000 cm-1 (172-400 nm). The observed polarization data provide information on the transition moment directions of the observed spectral features. The wavenumbers, intensities, and polarization directions of the observed spectral bands are compared with the results of quantum chemical calculations using the semiempirical all-valence-electrons method LCOAO and Time-Dependent Density Functional Theory (TD-DFT) with the functional CAM-B3LYP.

Automated summary

The UV absorbance spectra of trans-stilbene (DPE) and (E,E')-1,4-diphenyl-1,3-butadiene (DPB) were studied using Synchrotron Radiation Linear Dichroism (SRLD) spectroscopy with stretched polyethylene as an anisotropic solvent. The polarization data provided information about the transition moment directions of the observed spectral features. A comparison was made between the observed spectral bands and the results of quantum chemical calculations using LCOAO and TD-DFT with the CAM-B3LYP functional.