Effects of fluorine atoms on the optical nonlinear response of stilbene derivatives
|Title||Effects of fluorine atoms on the optical nonlinear response of stilbene derivatives|
|Publication Type||Journal Article|
|Year of Publication||2004|
|Romaniello, P, Lelj, F|
|Journal||JOURNAL OF FLUORINE CHEMISTRY|
|Date Published||FEB 2|
The effect of fluorine atoms on the second-order optical nonlinear response of 4-nitro-4'-methoxy-trans-stilbene and polyene derivatives containing up to three double bonds (n = 1, 2, 3) has been investigated within a semiempirical context (PM3 Hamiltonian). Experimental data reported in literature indicate a beta(vec)(SHG) value of 34,47 and 76(x10(-30) esu) for n = 1, 2, 3, respectively, at 0.65 eV in CHCl3 solutions. Our calculations show that fluorinating the nitrophenyl group the beta(vec)(SHG) is doubled. Further increase in the second-order nonlinear response can be obtained fluorinating the C=C bond linkers between the aromatic moieties. Besides, the effect of different donor-acceptor pairs has been studied and the results interpreted in the two-state model context. Some results concerning the third-harmonic generation (THG), gamma (THG), are presented, and a possible interpretation proposed. (C) 2003 Elsevier B.V. All rights reserved.