Theoretical and experimental studies of aryl-bithiophene based push-pull pi-conjugated heterocyclic systems bearing cyanoacetic or rhodanine-3-acetic acid acceptors for SHG nonlinear optical applications

• Autor(a) principal: Fernandes, Sara Sofia Marques
• Data de Publicação: 2018
• Outros Autores: Herbivo, Cyril, Sousa, João Aires de, Comel, Alain, Belsley, M., Raposo, M. Manuela M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/49645
• topic: Synthesis; Arylbithiophene; Cyanoacetic acid; Rhodanine-3-acetic acid; Density functional theory (DFT); Nonlinear optics (NLO); Second harmonic generation (SHG); Optoelectronics; DSSCs; UV-visible spectroscopy; Nonlinear optics; Ciências Naturais::Ciências Químicas; Science & Technology

A series of push-pull aryl-bithiophene based systems 2-3 were designed and synthesized in order to understand how structural modifications influence the electronic, linear and nonlinear optical properties. The push-pull conjugated chromophores 2-3 bear a bithiophene spacer conjugated with a phenyl ring functionalized with N,N-dialkylamino electron-donor groups together with cyanoacetic or rhodanine-3-acetic acid acceptor groups. Theoretical (DFT calculations) and experimental studies were carried out to obtain information on conformation, electronic structure, electron distribution, dipolar moment, and molecular nonlinearity response of the push-pull bithiophene derivatives. This multidisciplinary study revealed that chromophore 2e exhibits the highest value for hyperpolarizability beta (10440 × 10-30 esu) due to the strong electron donating ability of the N,N-diethylamino group, and the ethyne linker that not only lengthens the pi- conjugation path but also grants less distortion to the system.