Calculated and Experimental UV and IR Spectra of Oligo-para-phenylenes

• Published in: Bulletin of the Korean Chemical Society Vol. 35; no. 2; pp. 531 - 538
• Main Authors: Park, Kwangyong, Lee, Tae-Won, Yoon, Min-Ju, Choe, Jong-In
• Format: Journal Article
• Language: English
• Published: 대한화학회 20.02.2014
• Subjects: 화학
• ISSN: 0253-2964; 1229-5949; 1229-5949
• DOI: 10.5012/bkcs.2014.35.2.531

The quantum mechanical properties of a series of oligo-para-phenylenes (2-11) were characterized using DFT B3LYP/6-311G(d,p) calculations. The global minimum among the various torsional conformers of an oligo-pphenylene is calculated to be a twist conformation. A less stable planar conformation, in which all the dihedral angles in oligo-p-phenylene are restricted to be planar, has also been calculated. The total electronic energies, normal vibrational modes, Gibbs free energies, and HOMOs and LUMOs of the two different conformations (twisted and planar) of the oligo-p-phenylenes were analyzed. The energy differences between the HOMOs and LUMOs of the substrates are in accord with the maximum absorption peaks of the experimental UV spectra of 2-6. The calculated normal vibrational modes of 2-6 were comparable with their experimental IR spectra. KCI Citation Count: 10