Synthesis, characterization and photophysical properties of ESIPT reactive triazine derivatives

Abstract

Uma série de quatro compostos fotoativos derivados da triazina foi obtida a partir da substituição nucleofílica aromática no cloreto cianúrico. Os compostos foram caracterizados por espectroscopia de infravermelho (IR) e ressonância magnética nuclear (NMR de 1 H e 13 C), além de espectrometria de massas de alta resolução (HRMS MALDI). A espectroscopia de absorção na região do UV-Vis e a emissão de fluorescência (no estado sólido e em solução) foram também utilizadas para estudar o comportamento fotofísico destes compostos. Os derivados obtidos são fluorescentes na região do azul-laranja por um mecanismo de transferência protônica intramolecular no estado excitado e apresentam um grande deslocamento de Stokes (6365-10290 cm-1). Os derivados sintetizados neste trabalho reagiram com sucesso com fibras de celulose para dar novos compostos celulósicos fluorescentes. Four new reactive fluorescent triazine derivatives were obtained from nucleophilic aromatic substitution of cyanuric chloride. The compounds were characterized by infrared spectroscopy (IR), nuclear magnetic resonance (13 C and 1 H NMR) and high resolution mass spectrometry (HRMS MALDI). UV-Vis and steady-state fluorescence (in solution and in solid state) spectroscopies were also applied to characterize the photophysical behavior. The dyes are fluorescent by an intramolecular proton transfer mechanism (ESIPT) in the blue-orange region, with a large Stokes shift between 6365-10290 cm-1. The fluorescent cyanuric derivatives could successfully react with cellulose fibers to give new fluorescent cellulosic materials.

Morphology Controlled Synthesis of Heteroatom-Doped Spherical Porous Carbon Particles Retaining High Specific Capacitance at High Current Density

“…Another strong peak appears at 1557 cm −1 due to the presence of υ arom (CC) species. 42 The results support the formation of the product as illustrated in Scheme 1. On the other hand, the FT-IR spectrum of B (Figure S1b) shows a broad band at 3452 cm −1 due to the presence of the phenolic OH group.…”

Polyamidoamine‐Based Hydrogel for Removal of Blue and Red Dyes from Wastewater

“…The NN and CN stretchings were observed at 1420 and 1220 cm −1 , respectively. The vibration of CC aromatic moieties and ArO stretching were detected at 1339 and 1297 cm −1 . In Figure C, below 1200 cm −1 , the SO 3 stretching and aromatic ring vibrations are shown.…”

“…In the 1550–1650 cm −1 wavenumber region, a band was observed at 1611 cm −1 , indicating the CO stretching vibration mode present in the DB molecular structure . The presence of SO (SO 3 ) groups was suggested by bands arising at 1172 and 1045 cm −1 …”

Mathematical modelling of cellulase production and continuous production of enzymes under carbon-limited conditions by Trichoderma harzianum P49P11

“…The region between 3.1 and 4.5 ppm corresponds to the ring proton region from sugar residues, the region between 4.5 and 5.5 ppm is the anomeric proton region and the region from 1.2 to 2.3 ppm is the alkyl region (Elnahas et al, 2017). The region between approximately 7 and 8 ppm could indicate the presence of aromatic compounds (Kuplich et al, 2012). The highest signal is from the DMSO reagent.…”

“…The proton NMR spectrum of polysaccharides is mainly composed of three regions: ring proton region of sugar residues (3.1-4.5 ppm); anomeric proton region (4.5-5.5 ppm); and alkyl region (1.2-2.3 ppm) (Elnahas et al, 2017). The region between approximately 7 and 8 ppm could indicate the presence of aromatic compounds (Kuplich et al, 2012). Although proton NMR spectra are very informative, the results of samples with fully protonated molecules, high-molecular weights, and with a certain degree of heterogeneity are complex to interpret (Pomin, 2012).…”