The synthesis and full characterization of new chromophores with second order optical nonlinearities containing the 2- phenyl-(5,6)-nitrobenzimidazole group is reported. Starting from 2-{4-[(4-N,N-dihydroxyethylamino)phenylazo]phenyl}- 5(6)-nitrobenzimidazole, a combined theoretical and experimental approach, including theoretical computations of second order nonlinear optical activity (MNDO/AM1), X-ray structural analysis and synthetic strategies, has led to a significant optimization (more than 50%) of the NLO activity of related chromophores. The results indicate that 6-nitro-substituted compounds are more active than 5-nitro-substituted ones and that a further increase of NLO activity can be achieved by insertion of a carbon−carbon double bond between the benzimidazole and 2-phenyl rings. Calculations also suggest that an additional improvement of the nonlinearity should be expected upon functionalization of the N1 atom of the 6-nitrobenzimidazole with electron-withdrawing groups. Experimental nonlinearities (EFISH technique, μβ/ 10−48 esu, λ = 1.907 μm, DMF solution) between 940 and 1550 were measured.

Tuning second-order nonlinearities in push-pullbenzimidazoles

PELUSO, Andrea;
2004

Abstract

The synthesis and full characterization of new chromophores with second order optical nonlinearities containing the 2- phenyl-(5,6)-nitrobenzimidazole group is reported. Starting from 2-{4-[(4-N,N-dihydroxyethylamino)phenylazo]phenyl}- 5(6)-nitrobenzimidazole, a combined theoretical and experimental approach, including theoretical computations of second order nonlinear optical activity (MNDO/AM1), X-ray structural analysis and synthetic strategies, has led to a significant optimization (more than 50%) of the NLO activity of related chromophores. The results indicate that 6-nitro-substituted compounds are more active than 5-nitro-substituted ones and that a further increase of NLO activity can be achieved by insertion of a carbon−carbon double bond between the benzimidazole and 2-phenyl rings. Calculations also suggest that an additional improvement of the nonlinearity should be expected upon functionalization of the N1 atom of the 6-nitrobenzimidazole with electron-withdrawing groups. Experimental nonlinearities (EFISH technique, μβ/ 10−48 esu, λ = 1.907 μm, DMF solution) between 940 and 1550 were measured.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11386/1060149
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact