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5 mar 2024 · The auxochromic effect of the different substituents on the UV-Vis spectrum relative to alizarin will be analyzed by quantifying the changes in the relative positions of the ground and lowest excited electronic states.
31 sty 2022 · While the three UV-vis absorption spectra share the same general shape, it turns out that adding electron donating hydroxyl groups is shifting the spectrum from near UV (9,10-anthraquinone) to visible (alizarin: violet, purpurin: blue).
We focus on alizarin and its derivatives by introducing auxochromes in position C3 for simplicity since gradual changes are expected in the corresponding UV-Vis spectra and also because other positions would not provide active centers for convenient syntheses for new stable dyes.
Adjusting UV‐Vis Spectrum of Alizarin: Introduction of an electron‐donor group causes the transition bands to be significantly red‐shifted whereas electron‐withdrawing groups cause a minor blue‐shifting.
For such, we have performed a comprehensive study of electronic effects of substituents in position C 3 of alizarin by means of a time dependent DFT approach. These auxochromes attached to the chromophore are proven to alter both the wavelength and intensity of absorption.
1 wrz 2024 · By combining computational insights with experimental data, our study has demonstrated the great efficiency of the optimized computational protocol for accurately predicting UV–Vis spectra, CIELAB color coordinates, and NMR shift of alizarin, the main coloring molecule of Madder, and its analog alizarin red S.
26 wrz 2022 · The UV–vis absorption spectrum of an alizarin solution (alizarin red S, 150 ppm) showed three peaks of absorption: (1) at 240–280 nm, (2) 310–360 nm and (3) 400–550 nm wavelengths ...
