Experimental demonstration of the relationship between the second- and third-order polarizabilities of conjugated donor-acceptor molecules

Grant Bourhill, Lap-Tak A. Cheng, Christopher B. Gorman, Ging Lee, Seth R. Marder, Joseph W. Perry, M. J. Perry, Bruce G. Tiemann, Seth R. Marder, Joseph W. Perry
1994 Organic, Metallo-Organic, and Polymeric Materials for Nonlinear Optical Applications  
The dependence of the second-and third-order polaiizabilities (f3 and 'y) on ground-state polarization was measured for a series of donor-acceptor polyenes using electric field induced second harmonic generation and third harmonic generation, respectively. The changes in ground-state polarization, associated with the donor/acceptor strength or solvent polarity, were probed by x-ray crystallography, 1H-NMR, electronic absorption and Raman spectroscopies. The observed behavior of 3 and y as a
more » ... of 3 and y as a function of ground-state polarization agrees well with theoretical predictions. In particular, positive and negative peaks, as well as sign changes, were observed for both f and y. The dependences for 3 and 'y are consistent with a derivative relationship between them. In addition, the third-order polarizability of a series of molecules possessing zero bond length alternation was found to be negative, in agreement with predictions based on the relationship between the polarizabilities and ground-state geometry.
doi:10.1117/12.173815 fatcat:yrz64zmxjzaqpdgbuwappi2kjm