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Molecular and excited state properties of isomeric scarlet disperse dyes
- Source :
- Journal of Molecular Structure. 1161:254-261
- Publication Year :
- 2018
- Publisher :
- Elsevier BV, 2018.
-
Abstract
- This work was part of an investigation aimed at characterizing the molecular and excited state properties of currently available disperse dyes developed to provide stability to extensive sunlight exposures when adsorbed on poly(ethylene terephthalate) (PET) fibers. Having completed the characterization of yellow, magenta, and cyan disperse dyes for PET-based fabrics used outdoors, our attention turned to the colors designed to enhance the color gamut of a standard 4-member (cyan/yellow/magenta/black) color set. The present study pertained specifically to the characterization of commercially available scarlet dyes. In this regard, HPLC analysis showed that a scarlet product used for PET coloration was mainly a 70/30 mixture of dyes, and the use of HRMS and single crystal X-ray diffraction analyses indicated that these two dyes were azo compounds derived from isomeric pyridine-based couplers which differed in the location of the primary amino ( NH2) and anilino ( NHPh) groups attached to the pyridine ring. One dye structure has the NHPh group para to the azo group (Sc2), while the other has that group in the ortho position (Sc3). The presence of either ortho substituent provides photostabilization through intramolecular H-bonding with the azo moiety. Further, results from molecular modeling studies showed that the lower excited state oxidation potential of Sc3 relative to that of Sc2 allows Sc3 to function as an energy quencher for the excited state of Sc2 – through thermodynamically favorable electron transfer.
- Subjects :
- 010405 organic chemistry
Cyan
Organic Chemistry
Substituent
010402 general chemistry
Photochemistry
01 natural sciences
0104 chemical sciences
Analytical Chemistry
Inorganic Chemistry
chemistry.chemical_compound
Electron transfer
chemistry
Excited state
Pyridine
Structural isomer
Moiety
Magenta
Spectroscopy
Subjects
Details
- ISSN :
- 00222860
- Volume :
- 1161
- Database :
- OpenAIRE
- Journal :
- Journal of Molecular Structure
- Accession number :
- edsair.doi...........38cb64ba2207a08d32b19ff3a6a2999e