Polarized Vibrational Spectra of p-Substituted Nitro and Dinitro cis- and trans-Stilbenes (CROSBI ID 541347)
Prilog sa skupa u zborniku | sažetak izlaganja sa skupa | međunarodna recenzija
Podaci o odgovornosti
Miljanić, Snežana ; Meić, Zlatko ; Keresztury, Gabor
engleski
Polarized Vibrational Spectra of p-Substituted Nitro and Dinitro cis- and trans-Stilbenes
Polarized IR spectra of p-nitro and p, p’ -dinitro derivatives of stilbene were measured in anisotropic (nematic liquid crystalline) solvent. Using the Thulstrup-Eggers stepwise reduction procedure, based on the interactive subtraction of the two polarized IR spectra A(parallel) and A(perpendicular), orientational parameters of nearly planar, low symmetry stilbene molecules were determined. Dichroic ratios (subtraction factors), Ru (u = x, y, z), of observed vibrational transitions were evaluated and orientational parameters along the out-of-plane axis, Kx, the short in-plane axis, Ky, and the long in-plane axis, Kz, were calculated. Since the rotation around the double bond changes the molecular geometry, different set of orientation parameters were determined for each molecule. The Kz values indicate, as expected, that the trans-isomers are better oriented along the long in-plane axis than the cis-isomers. In addition, the Kz value for the mono substituted trans-stilbene, which is higher than the one for the disubstituted trans-stilbene, implies a possible involvement of the nitro groups in dipole-dipole interactions responsible for orientational mechanism of solute molecules in nematic solvent. Finally, polarized Raman spectra of crystalline stilbene substances were measured and depolarization ratios of selected vibration modes calculated. The values will be compared with those of the parent trans-stilbene molecule.
polarized spectrum; stilbene; vibrational spectroscopy
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
Podaci o prilogu
76-x.
2008.
objavljeno
Podaci o matičnoj publikaciji
EUCMOS 2008 Book of Abstracts
Musić, Svetozar ; Ristić, Mira ; Krehula, Stjepan
Zagreb:
978-953-6690-76-3
Podaci o skupu
XXIX European Congress on MOlecular Spectroscopy
poster
31.08.2008-05.09.2008
Opatija, Hrvatska