Luminescence studies

Emission spectra have been recorded for four aryl-substituted isoindoles rmder conditions of electrochemical stimulation. Electrochemiluminescence, which was easily visible in daylight, was measured at a concentration of 2-10 mM of emitter in V jV-dimethylformamide with platinum electrodes. Emission spectra due to electrochemi-luminescence and to fluorescence were found to be identical, and quantum yields for fluorescence were obtained by irradiation with a calibrated Hght source. Values are given in Table X. As with peak potentials determined by cyclic voltammetry, the results of luminescence studies are interpreted in terms of radical ion intermediates. ... 

U. Lemmer. R. F. Malm, Y. Wada, A. Greiner, H. Basslcv. E.O. Gobel, Time resolved luminescence study of recombination processes in electroluminescent polymers, Appl. Phys. Lett. 1993, 62, 2827. 

The story of luminescence advances since 1970 is best found in the current literature. It is too large and diversified to be readily summarized in a single article and too recent to edit for the most important events. Luminescence studies are so pervasive throughout all the fields of science that each special sphere of inquiry could have its own recent history of luminescence. Many of the most important developments of today will necessarily remain hidden to most scientists until later discoveries reveal their significance. For these reasons, this report continues with a personal selection of topics, chosen to guide the reader to a potpourri of interesting recent reports. 

Luminescence yields data that often cannot be provided by any other methodology. This book is a compilation of a wide variety of original research contributions. Substantial information is given on the use of luminescence techniques to understand specific cell responses and the chemical mechanisms of cell action. An examination of natural environments is presented in the form of specific studies that characterize materials in both solid and liquid form and give information on the respective reactions of these materials in soil and water systems. Advanced research on standardization and standards developed for luminescence studies, as well as both active and passive use of luminescence, is included. 

Luminescence studies revealed that compounds (119)-(121) displayed broad emission bands at 298 K, with ranging from 387 nm to 371 nm for the P to Bi derivatives, respectively [92]. On cooling to 77 K, compound (119) displays both a fluorescent band nm) and a phosphorescent... 

Bardaji, M., Laguna, A., Orera, V.M. and Villacampa, M.D. (1998) Synthesis, Structural Characterization, and Luminescence Studies of Gold(l) and Gold(lll) Complexes with a Triphosphine Ligand. Inorganic Chemistry, 37(20), 5125-5130. 

Syntheses and luminescence studies of mixed-metal gold(I)-copper(l) and -silver (I) alkynyl complexes. The tuming-on of emission upon d metal ion encapsulation. Dalton Transactions, 1830-1835. 

Luminescence studies of DMT in an ethanol glass at 77°K are reported to have shown a highly structured phosphorescent emission with maxima at 391, 404, 418, 432, and 446 nm and a mean... 

Based on luminescence studies, we postulated triplet-triplet energy transfer by electron exchange as the mechanism of photostabilization and we calculated an active quenching sphere with a radius, R0, of 19.7 A for 2,6-ND. Because the value of R0 is larger than 15 A, we postulated that energy migration was occurring. 

Nizomov N, Ismailov ZF, Nizamov SN, Salakhitdinova MK, Tatarets AL, Patsenker LD, Khodjayev G (2006) Spectral-luminescent study of interaction of squaraine dyes with biological substances. J Mol Struct 788 36-42... 

The hydration state of lanthanide(III) chelates can be assessed by different techniques. Luminescence studies are widely used for Eu111 and Tb111 chelates (see Chapter 9.21).17 18 170 NMR chemical shift measurements in solution of lanthanide(III) (most often Dy or Gd) complexes can also give information on q.19 These techniques in the context of MRI contrast agent research have been reviewed in 2001.1... 

A.M. Sarker, L. Ding, P.M. Lahti, and F.E. Karasz, Synthesis and luminescent studies of poly(/j-phenylene vinylenejs containing a biphenyl moiety, Macromolecules, 35 223-230, 2002. 

L. Sacksteder, A. P. Zipp, E. Brown, J. Streich, J. N. Demas, and B. A. DeGraff, Luminescence studies of pyridine a-diimine rhenium(I) tricarbonyl complexes, Inorg. Chem. 29, 4335-4340... 

J. W. Longworth, C. L. McLaughlin, and A. Solomon, Luminescence studies on Bence-Jones proteins and light chains of immunoglobulins and their subunits, Biochemistry 14, 2953-2959 (1976). 

Luminescence spectrum of scheelite with a broad gate width of 9 ms is shown in Fig. 4.9d. The narrow lines at 490 and 572 nm are usually ascribed to Dy and the lines at 607 and 647 nm to Sm " ". Nevertheless, the relative intensity of the line at 607 nm compared to the line at 647 nm is lower at longer delay times (Fig. 4.9e,f). Besides that with a shorter gate width of 1 ps, when the relative contribution of the short lived centers is bigger, the characteristic lines of Sm " " at 647 nm and Dy " at 575 nm disappear while the lines at 488 and 607 nm remain. Such luminescence is characteristic of Pr ", which was confirmed by a time-resolved luminescence study of scheelite artificially activated by Pr " and Sm " (Fig. 5.5). Unlike in apatite, the phenomenon exists not only under 308 nm, but also under 337 nm excitation due to the higher energy... 

Kimura, T. Choppin, G. R. 1994. Luminescence study on determination of the hydration number of Cm(III). Journal of Alloys and Compounds, 213/214,313-317. 

Photoconductivity (17,170) and transient absorption spectroscopy (36) studies indicate that (S+Au)-sensitization causes electron trap formation or deepens existing traps, but does not provide evidence that the traps are deeper than those produced by S-sensitization alone. Low-temperature luminescence studies likewise indicate that the gold does not enhance the electron trapping (172). 

Binding sites for Ca2+ and ATP have been explored by the use of metal probes and nucleotide analogues. The Mn2+ ion substitutes for Mg2+ but also binds at the Ca2+ sites. Such complications have led to the use of lanthanides134 as probes for the Ca2+ sites. Thus Gd3+ and Tb3+ compete with Ca2+ for the high affinity site. Luminescence studies with laser-excited Tb3+ at the Ca2+ sites show that two water molecules are present in the first coordination shell.151 Earlier work134 with Gd3+ shows that the Ca2+ sites are a maximum of 16.1 A apart, and that both sites involve a low level of hydration, consistent with a hydrophobic site. Gd3+ has also been used as an ESR probe, and, under certain conditions, evidence has been produced for two forms of an E-Gd34 complex, in accord with current mechanistic views. 

S S CONTENTS Preface, C. Allen Bush. Methods in Macromo-lecular Crystallography, Andrew J. Howard and Thomas L. Poulos. Circular Dichroism and Conformation of Unordered Polypeptides, Robert W. Woody. Luminescence Studies with Horse Liver Dehydrogenase Information on the Structure, Dynamics, Transitions and Interactions of this Enzyme, Maurice R. Eftink. Surface-Enhanced Resonance Raman Scattering (SERRS) Spectroscopy A Probe of Biomolecular Structure and Bonding at Surfaces, Therese M. Cotton, Jae-Ho Kim and Randall E. Holt. Three-Dimensional Conformations of Complex Carbohydrates, C. Allen Bush and Perse-veranda Cagas. Index. 

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