Phosphorescent paper

Copper(I) pyrazolate complex 8 was reported to show two phosphorescent properties depending on the cooling procedures to an ordered columnar phase from an isotropic phase by Aida and coworkers (Fig. 10) [34]. Compound 8 shows yellow phosphorescence after slow cooling with deliberate aging. On the other hand, red phosphorescence is observed by rapid cooling. A rewritable phosphorescent paper was prepared by using compound 8. 

Figure 2.43 Eiquid-crystalline copper(I) metallacrown complexes used for the preparation of phosphorescent paper (R = C H2 +i n — 12, 18)...

In room temperature phosphorescence, a treatment of the paper substrate with sodium dodecyl sulfate in conjunction with thallium acetate enhances the results and the technique can be used in routine environmental analysis of organic pollutants [156]. 

Solid-surface luminescence analysis involves the measurement of fluorescence and phosphorescence of organic compounds adsorbed on solid materials. Several solid matrices such as filter paper, silica with a polyacrylate binder, sodium acetate, and cyclodextrins have been used in trace organic analysis. Recent monographs have considered the details of solid-surface luminescence analysis (1,2). Solid-surface room-temperature fluorescence (RTF) has been used for several years in organic trace analysis. However, solid-surface room-temperature phosphorescence (RTF) is a relatively new technique, and the experimental conditions for RTF are more critical than for RTF. 

Interactions in Solid-Surface Luminescence Temperature Variation. Solid-surface luminescence analysis, especially solid-surface RTF, is being used more extensively in organic trace analysis than in the past because of its simplicity, selectivity, and sensitivity (,1,2). However, the interactions needed for strong luminescence signals are not well understood. In order to understand some of the interactions in solid-surface luminescence we recently developed a method for the determination of room-temperature fluorescence and phosphorescence quantum yields for compounds adsorbed on solid surfaces (27). In addition, we have been investigating the RTF and RTF properties of the anion of p-aminobenzoic acid adsorbed on sodium acetate as a model system. Sodium acetate and the anion of p-aminobenzoic acid have essentially no luminescence impurities. Also, the overall system is somewhat easier to study than compounds adsorbed on other surfaces, such as filter paper, because sodium acetate is more simple chemically. 

In their follow-up paper, they also demonstrated 100% efficient energy transfer of both singlet and triplet excited states. The device exhibits peak external efficiency and power efficiency of 25 cd/A and 17 lm/W at 0.01 mA/cm2, respectively [343]. Liu demonstrated a high-efficiency red OLED employing DCJTB as a fluorescent dye doped in TPBI with a green phosphorescent Ir(ppy)3 as a sensitizer. A maximum brightness and luminescent efficiency of... 

JJ Lih, CF Sung, MS Weaver, M Hack, and JJ Brown, A Phosphorescent Active-Matrix OLED Display Driven by Amorphous Silicon Backplane, Proceedings of the Society for Information Displays International Symposium Digest of Technical Papers, Vol. 34(Book 1), Baltimore, 2003, pp. 14-17. 

Y Tung, T Ngo, M Hack, J Brown, N Koide, Y Nagara, Y Kato, and H Ito, High Efficiency Phosphorescent White OLED for LCD Backlight and Display Applications, Proceedings of the Society for Information Display, Digest of Technical Papers, Vol. 35, Seattle, 2004, pp. 48-51. 

Under certain conditions phosphorescence can be observed at room temperature from organic molecules adsorbed on solid supports such as filter paper, silica and other chromatographic supports. 

Let us consider in detail a recent paper by Jones, Kearns, and Wing which represents one of the most thorough investigations of singlet-triplet transitions and reveals much of the power of the phosphorescence excitation method. 

Spectroscopic data of nitroaromatics have been reviewed D in addition, several papers on luminescence of nitroaromatic compounds have appeared recently. The phosphorescence polarization of several aromatic nitro compounds has been studied and recent triplet-triplet absorption data on 1- and 2-nitro-naphthalene have become available ). 

Since the 1960 s, stamp paper has been treated with fluorescent or phosphorescent phosphors. Since the stamp is stuck to the top right-hand corner of the letter, its recognition by the machine serves to establish the position of the letter and enables machine control of the correct positioning for postmarking and reading. Doped zinc sulfides with average particle sizes of 5-6 pm are used as afterglow phosphors. 

Site Inhomogeneity. In all cases where we observed phosphorescence emission from ketones in Silicalite the decay of this luminescence was non-exponential. In this respect, it should be noted that lifetimes given in Table I and in earlier papers in this series refer to the first observable lifetime following a 10 ys excitation pulse and a 20 ys delay. All values are comparable and probably reflect a similar degree of immobilization. Non-exponential decays... 

Therefore, we are interested in Pr and want to utilize the ability of Pr to develop novel red long phosphorescence. In this paper, we synthesized MBPO5 Pr (M=Ca, Sr, Ba) phosphors and made a tentative research. 

The question of energy transfer through proteins by various mechanisms has been considered in a recent symposium (Augenstine, 1960) and will not be discussed here, nor shall we discuss the studies of protein and amino acid luminescence from the solid state (phosphorescence) Debye and Edwards (1952, 1956). The photoinactivation of proteins will also not be considered. The recent paper by McLaren and Luse (1961) is suggested as a leading reference. 

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