Substituent effects on the photofading of disperse azo dyes on poly(ethylene terephthalate) substrate
The relationships between the chemical structures and oxidative fading of the disperse azo dyes, p-nitrophenylazo- and benzothiazoleazo-anilines, on poly(ethylene terephthalate) substrate are discussed in terms of the parameters k0,i (rate constants of reaction towards 1O2) and fi (photosensitivity), the molecular parameters of molecular orbital theory and substituents in the diazo and coupling components, on the assumption that the initial rates of oxidative fading are proportional to the product of k0,i and fi. 2-Methoxy-5-acetylamino-N-substituted aniline couplers exhibited large fi values. 2-Chloro and 4-nitro substituents of aniline diazo components exhibited small fi values or high quantum yields of internal conversion, while 4-nitro substituent did not. A close correlation between N-substituents and light fastness, proposed by Müller and supplemented by Dawson, demonstrates the applicability of frontier orbital theory, through the highest occupied molecular orbital (HOMO) energy of the dyes, to the analysis of oxidative fading. Dyes with N-2-cyanoethyl substituents, which gave a lower HOMO energy, also exhibited superior light fastness compared with N-2-hydroxyethyl substituents.
Congenital myasthenic syndromes (CMS) are heterogeneous disorders in which the safety margin of neuromuscular transmission is impaired by one or more specific mechanisms. Since the advent of next‐generation sequencing methods, the discovery of novel CMS targets and phenotypes ha ... mehr
Myasthenia gravis (MG) with antibodies to muscle‐specific kinase (MuSK) is characterized by fluctuating fatigable weakness. In MuSK MG, involvement of bulbar muscles, neck, and shoulder and respiratory weakness are more prominent than in acetylcholine receptor (AChR) MG. MuSK au ... mehr
Because of the failure of many promising therapeutics identified in preclinical evaluation, funding sources have established guidelines for increased rigor in animal evaluations. The myasthenia gravis (MG) community of scientists has developed guidelines for preclinical assessme ... mehr
John Wiley & Sons, Inc. stellt die Datenbank SpecInfo erstmals über die dynamische Internet-Plattform Wiley InterScience online zur Verfügung. Mit über 434 000 regelmäßig gepflegten Einträgen gehört SpecInfo zu den weltweit größten Spektrensammlungen.
SpecInfo bietet dem Benutzer eine int ... mehr