Estudo teórico - experimental das propriedades ópticas estruturais de derivativos de Triazenos

Abstract

The present work aims to investigate two triazene derivatives named 1-(2-amidophenyl)-3-(3- nitrophenyl)triazene (m-TZN) and 1-(2-amidophenyl)-3-(4-nitrophenyl)triazene (p-TZN), whose structures differ only by the position of the nitro group on the aromatic ring, this disconformity being the cause of divergence in the electronic distribution of the two molecules. Besides the two species, 1,3-diphenil-1-triazene (dph-TZN), the base structure originated from the two triazene derivatives, was also characterized theoretically and experimentally, aiming to elucidate the electronic structure to identify the influence of substituents and the position of the nitro group on the charge distribution. In addition, we sought to elucidate the electronic transitions and identify the regions with electrophiles and nucleophiles in the two triazene derivatives. Experimental ultraviolet absorption techniques were used to characterize the photophysical processes, while vibrational studies were based on Raman (FT-Raman) and infrared (FT-IR) spectroscopy analyses. In parallel, theoretical calculation methods based on density functional theory (DFT), theory level ωB97X-D3/Def2- TZVP were employed for the vibrational end absorption calculations in the UV-Vis, in order to assist in the interpretations of the experimental results.