The vibrational structure of ( E, E′)-1,4-diphenyl-1,3-butadiene

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 65; no. 3; pp. 770 - 778
• Main Authors: Hansen, Bjarke K.V., Møller, Søren, Spanget-Larsen, Jens
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2006
• Subjects: Density functional theory (DFT); Diphenylpolyene; Infrared; Linear dichroism (LD); Raman; Vibrational spectroscopy; Linear dichroism (LD); Raman; Diphenylpolyene; Infrared; Density functional theory (DFT); Vibrational spectroscopy
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2006.01.008

The title compound (DPB) was investigated by FT-IR spectroscopy in liquid solutions and by FT-IR linear dichroism (LD) measurements on samples aligned in stretched polyethylene. The LD data provided experimental assignments of molecular transition moment directions and vibrational symmetries for more than 40 vibrational transitions. The observed IR wavenumbers, relative intensities, and polarization directions were generally well reproduced by the results of a harmonic analysis based on B3LYP/cc-pVTZ density functional theory (DFT). The combined experimental and theoretical results led to proposal of a nearly complete assignment of the IR active fundamentals of DPB, involving reassignment of a number of transitions. In addition, previously published Raman spectra of DPB were well predicted by the B3LYP/cc-pVTZ calculations.