Naslov
Vibrational spectra and DFT calculations of PPV- oligomers

Autori
Hrenar, Tomica ; Mitrić, R. ; Meić, Zlatko ; Meier, H. ; Stalmach, U.

Izvornik
Journal of molecular structure (0022-2860) 661/662 (2003), 1; 33-40

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
p-Phenylenevinylenes ; PPV ; Vibrational analysis ; Density functional theory ; Potential energy distribution

Sažetak
The first two members of the p-phenylenevinylene- oligomer family (i. e. 1, 4-distyrylbenzene [DSB] and 4, 4'-distyrylstilbene [DSS]) were synthesized and their infrared and Raman spectra recorded and empirically assigned. Molecular geometries were optimized for the planar point group (C2h) by the density functional theory (DFT) method using the B3LYP functional and 6-31G* basis set. Calculations of vibrational spectra, including intensities, were carried out subsequently using the DFT method with the same basis set and linear scaling was applied. Calculated vibrational wavenumbers are in a fair agreement with our own experimental spectra. In order to explore changes in vibrational dynamics that are obtained with the extension of the chain, differences in potential energy distribution (PED) of normal modes are investigated and discussed. It was shown that B3LYP functional well describes the mentioned differences in infrared and Raman spectra and presents a sound basis for a more thorough research. The results are compared with those of trans-stilbene (tSB), a molecule structurally most closely related to the members of the p- phenylenevinylenes family.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA