Premium
Solvent‐Free Synthesis Using Nb 2 O 5 and a Theoretical‐Experimental Study of Solvent Effect in New Rhodamine Dyes
Author(s) -
Sacoman Torquato da Silva Bruno Henrique,
Olbera Riehl Luiza,
Carvalho dos Santos Giovanny,
Carlos Roldao Juan,
SilvaFilho Luiz Carlos
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201904486
Subject(s) - quantum yield , solvatochromism , photochemistry , solvent , molar absorptivity , absorption (acoustics) , rhodamine , chemistry , phthalic anhydride , fluorescence , solvent effects , yield (engineering) , catalysis , materials science , organic chemistry , physics , quantum mechanics , optics , metallurgy , composite material
Abstract Rhodamine dyes have several applications based on properties, such as high molar absorptivity, high fluorescence quantum yield, photostability, absorption and emission wavelengths in the visible region. In this paper, we describe the solvent‐free synthesis of rhodamines between m ‐aminophenol derivatives (3‐dimethylamino and 3‐diethylaminophenol) and phthalic anhydride derivatives (with and without halogens in the benzene ring) using Nb 2 O 5 as catalyst. The compounds were produced in high yields (79 to 90%) within one hour of reaction time and with catalyst recovery. Additionally, a solvatochromic study of rhodamine derivatives was described. These compounds have absorption and emission bands at wavelengths in the visible region and a high quantum yield that potentially makes them good dyes for use in electronic devices (e. g. lasers, OLEDs). The DFT calculations provided a basis for understanding the effect of the solvent on the structural forms of rhodamine and corroborated with the experimental data, where the zwitterionic form is predominant in polar solvents, while in apolar solvents the lactonic form is the most stable.