Theoretical nonlinear optics equivalence between mesoionic and polyenic bridges in push-pull compounds

• Autor(a) principal: Silva,Andréa M. S.
• Data de Publicação: 2005
• Outros Autores: Rocha,Gerd Bruno da, Menezes,Paulo Henrique, Miller,Joseph, Simas,Alfredo M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532005000400015
• topic: hyperpolarizabilities; polyenes; mesoionic

In this work we report a semiempirical investigation with the purpose of establishing an equivalence in terms of the value of the first static hyperpolarizability, beta(0), of push-pull compounds of the type electron-acceptor(A) - bridge - electron-donor(D), either formed by polyenic bridges or by mesoionic bridges, keeping unchanged both D and A groups. The ground state geometries of the molecules were optimized via AM1 using Mopac93r2 program. The value of beta(0) was calculated by time-dependent Hartree-Fock (TDHF). Our results indicate that a bridge formed by a single mesoionic ring can be equivalent to seven or more conjugated double bonds, depending on the ring, reaffirming that mesoionic rings constitute promising materials for photonics applications.