Challenging the auxiliary donor effect on molecular hyperpolarizability in thiophene-containing nonlinear chromophores: X-ray crystallographic and optical measurements on two new isomeric chromophores.
To reexamine the established "auxiliary donor" effect of thiophene in nonlinear optical (NLO) chromophores, we have prepared two isomeric donor-acceptor azo dyes, differing only in the position of the thiophene. Experimental analysis of these chromophores, including electric field-induced second harmonic generation (EFISH) and X-ray crystallography, contradicts previous experimental findings on similar chromophores but is consistent with the majority of computational precedents. We have found that the thiophene on the donor side produces a compound with a larger dipole moment; however, the isomer with the thiophene on the acceptor side is more nonlinear and has a higher figure of merit for NLO device applications.
Moylan
Christopher R
CR
Department of Electrical Engineering, University of California, 1156 High Street, Santa Cruz, California 95064, USA.
McNelis
Brian J
BJ
Nathan
Lawrence C
LC
Marques
Michael A
MA
Hermstad
Eric L
EL
Brichler
Benjamin A
BA
D001391:Azo Compounds / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004396:Coloring Agents / Q000737:chemistry; D018360:Crystallography, X-Ray; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013055:Spectrophotometry, Infrared; D013876:Thiophenes / Q000737:chemistry*
D001391:Azo Compounds; D004396:Coloring Agents; D013876:Thiophenes