Caracterização espectroscópica e por modelagem mecânico-quântica, de compostos com potencial aplicação em dispositivos ópticos não-lineares

Abstract

In the present work, the compounds 1-(3 ,4 ,5 -trimethoxiphenil)-2-(2 - tienyl) -5-(4 -nitrophenylazo) pirrol (compound 1) and 5 -dicianovinyl-5- piperidine-5,2 :5 :2 - tertiophene (compound 2), were characterized using a combination of spectroscopic measurements and quantum mechanical calculation, aiming to evaluate if they present the necessary requisites for application no photonic technologies. Both compounds present acceptable polarizability and first polarizability values, and high values of dipole moment, which tend to be higher for the relaxed S1 state, probably influenced by solvent interactions. These estimates were done using a theoretical methodology under development in Laboratório de Fotoquímica (IQUFU). These compounds present a solvatochromic behavior desirable for NLO ones, confirmed by theoretical estimates. Besides they possess asymmetry and electron delocalization important requisites to favor the intramolecular charge transfer (ICT) along the molecular structure, also possessing expressive values of dipole moment. These characteristics tend to facilitate the orientation of such compounds under conditions of electric field polarization. Both compounds also presents a low energy gap between the first excited electronic state and the ground state, considerable oscillator strengths, and expressive differences for the dipole moment between the first excited electronic state and the ground state, also expected requisites for compounds with potential application in photonics. Based on the collected information, compounds derived from these ones were proposed, which present increased NLO properties relative to their precursors.