Naphthalene fluorescence properties

Also, HPLC methods with electrochemical or fluorescent detection are used (H19, M3). In proteins, dityrosine can be estimated by immunochemical methods employing dityrosine-specific antibodies (K5). Measurements of o,o -dityrosine and o-tyrosine levels in rat urine express dityrosine contents in skeletal muscle proteins, and have been proposed as the noninvasive oxidative stress test in vivo. One should be aware, however, that A-formylkynurenine, also formed in protein oxidation, has similar fluorescence properties as dityrosine (excitation 325 nm, emission at 400-450 nm) (G29). Also, oxidation of mellitin when excited at 325 nm produces an increase in fluorescence at 400—450 nm, despite the fact that mellitin does not contain tyrosine. Oxidation of noncontaining Trp residues ribonuclease A and bovine pancreatic trypsin inhibitor with "OH produces loss of tyrosine residues with no increase in fluorescence at 410 nm (S51). There are also methods measuring the increased hydrophobicity of oxidized proteins. Assays are carried out measuring protein binding of a fluorescent probe, 8-anilino-l-naphthalene-sulfonic acid (ANS). Increase in probe binding reflects increased surface hydrophobicity (C7). 

Kramer s modeX may be due bo effects other than non-Markov/ian friction. The fluorescence properties of the conformational isom " mixtures of trans-2-stvrvl-naphthalene provides further evidence... 

The results of our studies will be presented in three sections. Tne first deals with the fluorescence properties of model naphthyl carbmates. This first section is particularly important in furnishing the background necessary to interpret the results in the next two sections vrfiich are concerned with the fluorescence of naphthalene diisocyanate (NDI) based polyurethanes in solution and film. 

Khoee et al. (2007a, 2007b) carried out the synthesis of photoactive poly(amide-imide)s containing anthracenic or naphthalenic pendent groups with fluorescent property in a domestic microwave. The reactions were performed in o-cresol solvent and yielded photoactive polymers in high yields. The microwave-assisted polycondensation reactions proceeded rapidly and were completed within 8-10 min. 

Further interesting example of NSAIDs, whose fluorescence properties within CD are determined by the mode of inclusion, are nabumetone (10), a naphthalene derivative with a butanone side chain and naproxen (11), a parent propionic acid derivative (Fig. 2). The dominant features of the inclusion of nabumetone inside P-CD are the formation of two conformations of the drug, but the folded structure is the main one, probably due to the presence of water in the proximity of the hydroxyl groups at the gates of CD [59]. This situation... 

The high-spin/low-spin interconverison in a Ni11 complex of the cyclam derivative (639) bearing a luminescent naphthalene substituent has been used as a fluorescent molecular thermometer.161 The Ni11 tends to quench fluorescence of the proximate naphthalene subunit, but the two spin states exert a different influence on the emission properties. Emission is temperature dependent, since the high spin —> low spin conversion is endothermic, i.e., a temperature increase favors formation of the low-spin form. 

Dinaphthotetraazaporphyrins are structural isomers of phthalocyanines. The zinc complex was formed and the properties compared to zinc phthalocyanines demonstrating a lower fluorescence quantum yield for the zinc-fused naphthalene porphyrin (D2h symmetry) vs. the zinc phthalocyanine (D4h)S36... 

Weber G, Farris FJ (1979) Synthesis and spectral properties of a hydrophobic fluorescent probe 6-propionyl-2-(dimethylamino)naphthalene. Biochemistry 18 3075-3078... 

Weber G. and Farris F. J. (1979) Synthesis and Spectral Properties of a Hydrophobic Fluorescent Probe 6-Propionyl-2-(Dimethylamino)naphthalene, Biochemistry 18, 3075-3078. 

Two-substituted naphthalene thienyl oligomers have been characterized for their photophysical properties (09PCCP8706). The compound 7 showed absorption at 405 nm and an emission at 475 and 502 nm. The fluorescence quantum yield was 0.27 and tf 0.56 ns. The quantum yield for the internal conversion was 0.05, while the triplet quantum yield resulted to be 0.68. 

Within their scaffolds, POPAM dendrimers also possess amine groups which can undergo protonation or coordination with metal ions. The spectroscopic and photochemical properties of the first to the fourth POPAM generation with peripheral fluorescing naphthylsulfonamide groups were compared with those of reference compounds A (N-methylnaphthalenesulfonamide) and B (N-(3-di-methylaminopropyl)-2-naphthalene-l-sulfonamide) [22] (Fig. 5.19). 

Detailed experimental procedures have been previously reported (Ko, 1998 Ko et al., 1998a,b) therefore, they are only briefly described here. Phenanthrene (Aldrich, 99.5+%), naphthalene (Aldrich, 99+%), SDS (Sigma, 99.5+%), and Tween 80 (Aldrich, no purity reported) were used as received selected physicochemical properties for these compounds are shown in Table 1. Kaolinite, a nonswelling 1 1 layer phyllosilicate clay and common constituent of many subsurface environments, was used as received from Sigma. Solution pH and ionic strength were adjusted as necessary with 0.5 M HC1 and/or 0.5 M NaOH and NaCl, respectively. Aqueous phenanthrene and naphthalene concentrations were quantified by fluorescence (PTI, Inc.) at the excitation/emission wavelengths of 250/364 and 278/322 nm, respectively. A total organic carbon (TOC) analyzer (Shimadzu Model 5050) was used to determine aqueous SDS concentrations and Tween 80 concentrations were determined by UV absorbance at 234 nm. 

The high sensitivity and specificity of photoluminescence analysis should make it possible to individualize clue materials, e.g., hair and glass, by the characteristic luminescence properties of trace constituents or impurities. Of particular significance are the newer techniques of analyzing the luminescence decay curves. For example, even when the absorption and luminescence spectra of the impurities are similar, it is possible to determine their concentrations if their luminescence lifetimes differ. The usefulness of this technique is illustrated in Figs. 1 and 2, where it is shown that the fluorescence spectra of naphthalene (N) and 1,6-dimethyl napthalene (DMN) are too similar for fluorescence spectral analysis of their mixtures (Fig. l) yet their relative concentrations can be readily determined from the fluorescence decay curve (Fig. 2). As indicated by the dashed curve in Fig. 2, the observed decay is the sum of exponential decays from a shorter lived component, i.e., DMN (lifetime 50 nsec) and a longer lived component, i.e., N (lifetime 100 nsec). St. John and Winefordner (j) have discussed this technique in general and Hoerman and co-workers (8,9) have been... 

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