UV and Fluorescence Spectroscopy

For UV spectra of parent and substituted 1,2,3-triazoles and benzotriazoles, see CHEC-I 84CHEC-1(5)684 . The UV spectra of benzotriazole, 1-methyl- and 2-methyl-benzotriazole in the gas phase at 90°C have been recorded 94JOC2799 . 1-Alkyltriazolines show two A ax in acetonitrile, 239-242 and 263-266 nm, both with log e w 3.50 93JOC2097 . The UV spectra of bicyclic triazolines (754) have been recorded 9lJOC4463 . The Si-So electronic absorption spectrum of 1/f-benzotriazole at 286 nm has been studied by computer simulation of the rotational contours. The result shows that the benzotriazole band is an almost pure type-5 band 93JSP(158)399 . 

UV spectroscopy is of importance in studying the tautomerism of 5,5-diphenyl-4/7-l,2,3-triazol- 

4- one and 5-amino-4,4-diphenyl-4/7-1,2,3-triazole. The comparison of UV and other spectra of the tautomeric triazoles (60) and (62) with those of the V-methyl compounds (61) and (63) demonstrates that the tautomers (60a) and (62b) are strongly favored in solution 93CB103 . The UV absorption bands and IR spectrum of l,4,4-trialkyl-4,5-dihydro-5-imino-l/7-l,2,3-triazole (64) are also described 90CB2195 . 

Some 2-(2 -hydroxyaryl)benzotriazoles are UV stabilizers and they have received much attention as a result of their UV and fluorescence properties see review B-90MI 401-01). The UV spectra of benzotriazoles (65b, c) in heptane and methanol have been measured. The UV absorption of (65c) is markedly dependent on the solvent (340 nm in heptane and 280 nm in methanol) perhaps because of intermolecular hydrogen bonding. In contrast, the absorption spectrum of (65b) is relatively insensitive to solvents 81AJC69l). The absorption and fluorescence characteristics of 2-(2 -hydroxy- 

Solvent Wavenumber and e of absorption maxima Wavenumber of emission maxima  

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In recent years nonlinear optical materials on the basis of nitroazoles, especially nitrobenzoxazoles and nitrobenzoxadiazoles, have investigated under intense scrutiny, at that and UV and fluorescence spectroscopy is widely used in studying of their structure and dynamics [1202-1225], 4-Aminosubstituted 7-nitrobenzofura-zans have a strong band in the visible region ( =457-483 nm) due to their chromophore properties [777]. 4-Substituted 7-nitrobenzofurazans possess a strong fluorescence that has led to their use as biochemical fluorescent probes in cell membranes [777, 1226-1228],... 

UV and fluorescent spectroscopy can be employed down to 190 nm because there is no solvent interference. Mass spectrometry is easy because the water provides good ionization. Flame ionization detection (FID) is of particular interest because potentially it offers a sensitive and universal detector. A number of different interfaces have been used, including heated capillaries, which have been examined by Miller and Hawthorne [62], Ingelse et al. [63], and others [64, 65], who separated a range of analytes including alcohols, amino acids, and phenols. An alternative method employing a cold nebuliza-tion of the eluent has been introduced by Bone et al. [66]. They were able to detect both aliphatic and aromatic alcohols, polymers, carbohydrates, parabens, and steroids. 

Tar sampling of the product gas stream is usually carried out in accordance with technical specification CEN/TS 15439 [44], In addition to gas chromatographic analysis, innovative methods have been proposed for monitoring and characterizing tar produced in gasification processes the methods include HPLC-UV and fluorescence spectroscopy, which provide rapid and relatively cost-effective procedures [45]. 

Cutinase Fusarium solani Fabric UV and fluorescence spectroscopy, dye assay, water absorption tests Hydrolysis, increased hydrophilicity, improved dye uptake [3, 6, 38, 82, 84, 85, 98]... 

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