Triazene 1-oxide compounds: Synthesis, characterization and evaluation as fluorescence sensor for biological applications

The compound 1-methyl-3-p-(carboxyphenyl)triazene 1-oxide is unidimensionally polymerized by classical hydrogen bonds in the direction of the crystallographic axis a. The synthesis and structural characterization by spectroscopic and non-spectroscopic methods as well as the influence of solvents on the fluorescent properties of triazenes 1-oxide are discussed in this work. •Spectroscopic and structural characterization of two triazene 1-oxide compounds.•X-Ray determinations on single crystal.•Comparative fluorescence study.•Evaluation as potential fluorescence sensor. Triazene compounds have been known for over 100years. This class of compounds is versatile because they have different applications as chemical and biological reagents. Currently, the tendency of applications of triazenes is as fluorescence sensors with biological and environmental functions. This work discusses the synthesis and structural characterization through IR, MS (EI), 13C NMR, 1H NMR, DSC and TGA analyzes of two triazene compounds, namely, 1-methyl-3-(p-carboxyphenyl)triazene 1-oxide (1) and 1-methyl-3-(phenyl)triazene 1-oxide (2). A comparative fluorescence study between these triazenes as potential compounds for application in the chemical sensors has also been carried out. The molecular and supramolecular structure of compound (1) is also determined by X-ray diffraction on single crystal, where the classic hydrogen bonds give the tridimensional arrangement. The presence of para-carboxylic group in compound (1) as well as the polarity and viscosity of the tested organic solvents resulted in a great influence on the evaluation of the fluorescence effect. These experimental findings show the potential use of triazenes as fluorescent biosensors, since the compounds (1) and (2) present antimicrobial activity.