Fluorescence 2- benzoxazol

Discussion. Cadmium may be precipitated quantitatively in alkaline solution in the presence of tartrate by 2-(2-hydroxyphenyl)benzoxazole. The complex dissolves readily in glacial acetic acid, giving a solution with an orange tint and a bright blue fluorescence in ultraviolet light. The acetic (ethanoic) acid solution is used as a basis for the fluorimetric determination of cadmium.28... 

In a recent evaluation of this phenomenon, the whiteness indices given by eleven individual brighteners on polyester were compared with those of their binary mixtures in various ratios. In many cases the whiteness performance of a mixture was markedly superior to that shown by the individual components [57]. A more specific investigation was confined to a series of benzoxazole FBAs. Their fluorescence spectra and fluorescence lifetimes were determined individually and in mixtures. The relationships between molecular structure and photophysical properties were discussed [58]. 

Wang H, Zhang H, Abou-Zied OK et al (2003) Femtosecond fluorescence upconversion studies of excited-state proton-transfer dynamics in 2-(20-hydroxyphenyl)benzoxazole (HBO) in liquid solution and DNA. Chem Phys Lett 367 599-608... 

A wide variety of different classes of fluorescent molecules has been investigated in the peroxyoxalate chemiluminescent systems. Among those screened were fluorescent dyes such as rhodamines and fluoresceins, heterocyclic compounds such as benzoxazoles and benzothiazoles, and a number of polycyclic aromatic hydrocarbons such as anthracenes, tetracenes, and perylenes. The polycyclic aromatic hydrocarbons and some of their amino derivatives appear to be the best acceptors as they combine high fluorescence efficiency with high excitation efficiency in the chemiluminescent reaction [28],... 

Thienyl-substituted benzoxazoles have been studied for their potential application for fluorescent sensors of metals. They showed absorption bands near 315 nm and emission at 393-394 nm (Of = 0.66-0.80) (07MI2096). Thienyl-substituted imidazopyridines show absorption bands in the range 309-340 nm and emit in the range 474-533 nm (09T5062). Bithienyl-imidazo-anthraquinone derivatives were studied showing an absorption band at 444 nm (070L3201). 

The effects of a-, (3-, y-, and 2,6-di-o-methyl-(3-CDs on the ground- and excited-state properties of 2-(2 -hydroxyphenyl)benzoxazole (HBO), 2-(2 -hydrox-yphenyl)benzothiazole (HBT), and 2-(2 -hydroxyphenyl)benzimidazole (HBI) (42) in aqueous media have been investigated using fluorescence [184], The molecules form 1 1 complexes with a reasonably high association constant, and they enter the cavity axially from the wider-rim side of (3-CD with the benzazole... 

It is interesting to note that 5-nitrobenzoxazole has two absorption maxima 224 (4.39) and 270 nm (3.84), while 6-nitrobenzoxazole shows only one maximum in area Amix 282 nm (4.01) [1200], A similar pattern is observed for 5-nitro- and 6-nitro-2-alkyl(aryl)benzoxazole too. The available experimental data are not enough to explain spectral differences of this kind. Apparently, it would be well to carry out quantum-chemical calculations or to involve other physical-chemical methods. An investigation of chromophoric 2-(4 -diphenyl)-5-nitrobenzoxazole with the help of UV (A 305 nm), fluorescence and laser spectroscopy has been reported by Chinese chemists [1201], Chromophores 2-(2 -hydroxy-4 -aminophenyl)-6-nitrobenzoxazole [ 1202], 2- [4-[4-(V,V-dihydroxyethyl-amino)-phenylazol]-phenyl -6-nitrobenzoxazole, 2-[4-(/V-mcthyl,V-hydroxyethyl-amino)... 

Rai V. K., Srivastava R., Kamalasanan M. N. White organic electroluminescence from fluorescent bis (2-(2-hvdroxvphenyl) benzoxazolate) zinc doped with phosphorescent material lournal of Luminescence, 130, 2, (February 2010), 249-253... 

Rai V. K., Sriva stava R., Kamalasanan M.N. White oreanic light-emittine diodes based on blue fluorescent bis(2-(2hvdroxvphenvl)benzoxazolate)zinc (Zn(hpb)fl doped with PCM dve. Synthetic Metals, 159, 3-4, (February 2009), 234-237... 

Hydroxyphenyl)benzoxazole [835-64-3] M 211.2, m 127 , b 338 /760mm. Recrystallise it several times from aqueous EtOH or dilute AcOH and sublime it. An aqueous alkaline solution containing EtOH has a blue fluorescence. [Itoh Fujiwara J Am Chem Soc 107 1561 1985, Beilstein 27 II 91.]... 

To illustrate the kind of systems that have been achieved since that time, we present two examples. The first one uses two cyanine dyes carrying long alkyl chains, the oxacyanine dye (23) and the thiocyanine dye (24). The benzoxazole ring in compound (23) has an absorption band in the UV and it fluoresces in the blue. The benzothiazole ring in compound (24)... 

It should be noted that there is also a large body of literature on the photophysics of benzoxazole derivatives, which is outside of the scope of this review but clearly of relevance to those in the field. Leading references are provided for benzoxazole itself " and the widely studied oxazole yellow fluorescent dyes and their interactions with DNA strands. 

Oxazoles and benzoxazoles with an aryl substituent at C2 are strongly fluorescent and can act as an optical brightener. Some washing agents include 4,4 -bis(benzoxazol-2-yl)stilbene as an additive. The additive is... 

Bis (benzoxazol-2-yl) naphthalene brightener, fluorescent paper 7-Diethylamino-4-methylcoumarin brightener, fluorescent plastics 7-(4-Amino-6-diethylaminotriazin-2-yl) amino-3-phenylcoumarin 7-(4-Chloro-6-diethylaminotriazin-2-yl) amino-3-phenylcoumarin Cl fluorescent brightener 236... 

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