Acridine absorbance

The presence of MEF, MEP and Metal-Enhanced superoxide anion radical generation in the same system seems surprising at first, as these processes are effectively competitive and ultimately provide a route for deactivation of electronic excited states. As recently shown by the authors, simultaneous photophysical mechanisms can be present within the same system when enhanced absorption effects of the fluorophore near to silver are present (i.e. an enhanced excitation rate). In this case, enhanced absorption of Acridine near-to the plasmon resonant particles facilitates MEF, MEP, ME Oa and also Metal-Enhanced superoxide generation simultaneously within the same system. Aaidine showed an enhanced absorption spectra near-to silver, similar to other probes reported by the authors, in essence acridine absorbs more light. ... 

Fig. 34. Stepwise decay of radical anion of acridine in PMMA containing 0.26 mole dm-3 acridine. Absorbed dose 0.2 Mrad at 77°K (optical density measured at 635 nm) [259].

Ubichromenol synthesis, 3, 752 Ugi reaction, 5, 830 Uliginosin B, bromo-molecular dimensions, 3, 621 Ullman and Fetvadjian synthesis quinolines, 2, 477 Ullman synthesis acridines, 2, 470-benzacridines, 2, 470 Ultraviolet light absorbers in polymers, 1, 397-398 Ultraviolet spectroscopy heterocyclic compounds reviews, 1, 78... 

Acriflavin Mixture (Euflavin, 3,6-diamino-lO-metbylacridiniuni chloride) [8063-24-9] M 259.7, m 179-181 . Purified by dissolving in 50 parts of H2O, shake with a small excess of freshly ppted and washed Ag20. The mixture is set aside overnight at 0 and filtered. The cake is not washed. The pH of the filtrate is adjusted to 7.0 with HCl and evaporated to dryness. The residue is then crystd twice from MeOH, twice from H2O and dried at 120 X ,ax at 452nm has a loge value of 4.67. It is a red powder which readily absorbs H2O. The solubility is increased in the presence of proflavin. The dihydrochloride is a deep red crystn powder. It is available as a mixture of 3,6-diaminoacridinium chloride (35%) and its 10-metho-chloride (65%). [see Albert, The Acridines Arnold Press p. 346 1966 Chem Ber 45 1787 1912]. 

Diaryl- and triaryl-methane dyes also fall into this class [(124) is known as Michler s Hydrol Blue] and a number of the heterocyclic derivatives of these dyes are well known. Introduction of a sulfur bridge into Michler s Hydrol Blue (124) results in the dye Thiopyronine (125) which absorbs at 565 nm. The analogous dye with an oxygen bridge, Pyronine, absorbs at 545 nm and that with an —NH— bridge, Acridine Orange, absorbs at 490 nm (B-76MI11201). 

If the photochemical reaction is followed only by measuring the concentration of the light-absorbing ketone, it will indeed appear that the additive (acridine) acts as a quencher in reality it acts as a radical scavenger through a thermochemical reaction which is quite unrelated to the nature of the reactive excited state. 

Several dyes have been found to sensitize the cationic polymerization of cyclohexene oxide, epichlorohydrin, and 2-chloroethyl vinyl ether initiated by diaryliodonium salts (109,110). Acridinium dyes such as acridine orange and acridine yellow were found to be effective sensitizers. One example of a benzothiazolium dye (setoflavin T) was also reported, but no other class of dye nor any other example of a dye absorbing at longer wavelengths were discovered. Crivello and Lam favored a sensitization mechanism in which direct energy transfer from the dye to the diaryliodonium salt occurred. Pappas (12,106) provided evidence that both energy transfer and electron transfer sensitization were feasible in this system. 

Fig. 2. Acidification of small synaptic vesicles by glutamate and chloride in synap-tosomes. The acidification assay was performed as described in section 3.2 of this chapter. Two representative experiments with intact (upper trace) or SLO-permeabilized (lower trace) synaptosomes are shown. The ordinate gives the changes of absorbance obtained (A 492-530). Final concentrations of potassium glutamate (Glut), KCl, and ammonium sulfate (NH/) were 10 mM, 45 mM and 30 mM, respectively. The uptake of glutamate and chloride result in an acidification of the lumen of small synaptic vesicles, which increases the vesicular uptake of acridine orange, resulting in a decrease in the amount of extravesicular dye. This acidification can be only observed when the plasma membrane is permeabilized...

Epifluorescent techniques use fluorescent dyes that either exhibit different colours in living and dead cells (e.g. acridine orange) or appear colourless outside the cell but become fluorescent when absorbed and subjected to cellular metabolism (e.g. fluorescein diacetate). 

Absolute fluorescence timing, 226f Absorbance spectra, for albumin solution, 71f Absorbance spectrometry multiwavelength measurement, 66f wide dynamic range array, 57-74 Acridine... 

Twenty-eight patients that required coal tar treatment on an area larger than two-thirds of the body surface were studied (Cemikova et al. 1983). Tar paste (10 and 20%) was used for treatment in one application, approximately 1-6 g of coal tar containing 0.6% acridine was spread on the patient s skin. Urine analysis was performed by TLC to obtain information on polyaromatic and heterocyclic substances excreted in the urine. Further identification of the substance was performed by GC/mass spectrometry (GC/MS). The presence of acridine in urine after the coal tar application was identified by MS. The detection of acridine in urine provided proof of the absorption of a coal tar component through the skin. However, without additional information, no statements can be made regarding the dermal absorption of other coal tar components or whether acridine was preferentially absorbed through the skin. 

An acid partition and alumina column clean-up procedures were used to analyze for several acridines (HPLC/UV) in creosote by Galceran et al. (1994). HPLC with fluorescence detection was used for analysis of the PAH components from a coal tar sample (NIST SRM 1597) as reported in a review article by Wise et al. (1993). Since fluorescence detection affords more selectivity than UV absorbance... 

Absorbed dose 0.15 Mrad at 77°K. A = radical anion of acridine C = radical cation of acridine R = neutral radical [175],... 

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