Síntese dos derivados de fenildiamina contendo o marcador fluorescente dansila visando aplicação como sonda fluorescente e na síntese de polímeros conjugados e c-dots

Abstract

Aromatic amines are characterized by having in their structure one or more aromatic systems attached to the nitrogen atom, such as phenyldiamines. These may undergo acid-base reactions, alkylation, acylation, among others, which allows the formation of heterocyclic, azo and fluorescent compounds. Among the various fluorescence amines, the dansylated ones, which present double fluorescence with only one excitation, stand out due to the TICT phenomenon present in these molecules. In view of this, the dansylated o, m and p-phenylenediamine derivatives were synthesized in optimum yields from a nucleophilic acylic substitution reaction between dansyl chloride and o, m and p-phenyldiamine. After characterization by 1H NMR, 13C NMR and FTIR, the obtained derivatives were submitted to fluorescence emission tests, which showed emission of fluorescence in different solvents, having influence of the polarity and viscosity of these, coherent with that expected for dansilated molecules due to to the TICT phenomenon.The o-phenyldiaminadansila was studied as a fluorescent probe for the detection of metal cations ions in water, which demonstrated a potential for on-off probe detection for Al3 + ions. The p-phenyldiaminadansyl, dansyl chloride and p-phenyldiamine were used as precursors of Carbon Dots (C-dots) in hydro and solvotermal reaction by the bottom-up route. The obtained C-dots exhibited functional groups characteristic of the precursor materials, diameters less than 6 nm, excitation wavelength dependent emission and presented the potential for application in the assembly of white LEDs by the RGB system. The ortho and meta derivatives were submitted to electrochemical polymerization, with no formation of polymers as well as a sensitivity at pH ~ 2.