Characterization, purification, and analysis of solvent yellow 33 and solvent green 3 dyes

The structure and purity of a reference dye standard used for quantification of C.I. Solvent Red 164 in fuels

“…Components in these mixtures may vary widely in their volatility, polarity, and molecular weights [2]. Even dyes that are purportedly pure are occasionally found to contain substantial amounts of impurities [3]. Dye compositions are difficult to completely characterize due to the broad range of possible products and, therefore, require several different analytical techniques, each with their unique capabilities, to obtain complete characterization.…”

Femtosecond Extreme Ultraviolet Photoelectron Spectroscopy of Organic Molecules in Aqueous Solution

“…NMR spectroscopy, 31 vibrational spectroscopy, 30 and computational studies 32 conclude that in solution quinophthalone takes the enamino form and suggest that this tautomer is likely responsible for the photoabsorption properties of the molecule, owing to its extended conjugated system. 31 Recently, relaxation dynamics of quinophthalone attracted interest, possibly featuring an uncommon N-to-O excited-state intramolecular proton transfer (ESIPT). 33 We first conduct XUV-only experiments to access the ground-state photoelectron spectrum of the QY molecule in solution.…”

“…The results suggest that the planar enamino structure, with the hydrogen located at the nitrogen atom, is favored in the QY, similar to the results reported for quinophthalone. 30,31 The influence of sulfonation on molecular structure appears to be negligible. Vertical ionization energies of the relevant molecular orbitals are shown in Figure 2 as sticks.…”

“…Quinophthalone can assume three main tautomeric forms: one keto and two enol forms (see Figure a). NMR spectroscopy, vibrational spectroscopy, and computational studies conclude that in solution quinophthalone takes the enamino form and suggest that this tautomer is likely responsible for the photoabsorption properties of the molecule, owing to its extended conjugated system . Recently, relaxation dynamics of quinophthalone attracted interest, possibly featuring an uncommon N-to-O excited-state intramolecular proton transfer (ESIPT) …”