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'fluorescence' in keywords Facet section ZfN Section A [X]

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1	Author	Snezhana Bakalova	Requires cookie*
	Title	S
	Abstract	o lv e n t E f fe c ts o n th e F lu o re s c e n c e P r o p e r tie s o f M e th y ld ih y d ro q u in o lin o n e s The absorption and fluorescence spectra and the fluorescence quantum yields of two methyl-2,3-dihydro-4(lH)-quinolinones in various solvents are reported. In some solvents deuteration-induced fluorescence enhancement has been observed. The solvent effects in aprotic solvents are consistent with the general type of solvent interaction. For protic solvents, solute-solvent complexation in the excited state is suggested.
	Reference	Z. Naturforsch. 46a, 823—827 (1991); received May 24 1991
	Published	1991
	Keywords	Fluorescence, Dihydroquinolinones, Hydrogen bond
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	TEI-XML for	default:Reihe_A/46/ZNA-1991-46a-0823.pdf
	Identifier	ZNA-1991-46a-0823
	Volume	46

2	Author	HansE. Wilhelm, Horst Gebert, Wolfgang Regenstein	Requires cookie*
	Title	Effect of Substituents on the Viscosity Dependence of Fluorescence and on the S l -T l Energy Gap of Donor-Acceptor Substituted Trans-Stilbenes
	Abstract	The dependence of fluorescence quantum yields and Sj-lifetimes of donor-acceptor substituted trans-stilbenes on temperature was measured in the temperature range from 298 to 100 K, using solutions of stilbenes in 3-methylpentane (3-MP). Measurements of fluorescence and phosphores-cence spectra show that the triplet energy is almost independent of the acceptor. The S[-energy and the S r Ti energy gap decrease with increasing acceptor strength. For all compounds intersystem crossing (ISC) S, —» T, is negligible.
	Reference	Z. Naturforsch. 52a, 837—842 (1997); received November 18 1997
	Published	1997
	Keywords	Stilbenes, Fluorescence, Phosphorescence, Singlet-Triplet Energy Gap, Rate Constants
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	TEI-XML for	default:Reihe_A/52/ZNA-1997-52a-0837.pdf
	Identifier	ZNA-1997-52a-0837
	Volume	52

3	Author	Peter Nikolov, Irina Petkova, Stefan Stoyanov3	Requires cookie*
	Title	Media Effect upon the Fluorescence Ability of Differently Substituted a-Cyanostilbenes
	Abstract	The steady state and dynamic photophysical characteristics of a-cyanostilbene derivatives have been investigated in solution and in Polyvinylchloride (PVC) film at 300 K as well as in a frozen matrix at 77 K. While no emission is observed in solution, a significant fluorescence ability is registered both in PVC and frozen media. This fact is attributed to the matrix effect, which lessens the possible intramolecular motions around the central double bond. No phosphorescence at 77 K is observed. The fluorescence lifetimes at 77 K are compared with literature data for similar chemically fixed structures.
	Reference	Z. Naturforsch. 56a, 447—451 (2001); received January 23 2001
	Published	2001
	Keywords	a-Cyanostilbene Derivatives, Fluorescence, Matrix Effect
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	TEI-XML for	default:Reihe_A/56/ZNA-2001-56a-0447.pdf
	Identifier	ZNA-2001-56a-0447
	Volume	56

4	Author	I. Timtcheva, P. Nikolov, St Minchevand, N. Sofroniev	Requires cookie*
	Title	Luminescence Properties of Some 4-or 5-Aminosubstituted Indan-13-Diones
	Abstract	The photophysical characteristics of some 4(5)-amino-2-aryl-and 4(5)-amino-2-aryl-2-carboxy-methyl-l,3-indandiones have been studied in solvents of different polarity at room temperature and at 77 °K. In contrast to the 2-arylindan-l,3-diones unsubstituted in the phthaloyl fragment, the compounds investigated are photostable and fluoresce in the region 25 000-18 000 cm -1 with fluorescence quantum yields between 0.1 and 0.5.
	Reference	Z. Naturforsch. 42a, 289—292 (1987); received October 22 1986
	Published	1987
	Keywords	4-and 5-amino indan-l, 3-diones, absorption, fluorescence, phosphorescence
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	TEI-XML for	default:Reihe_A/42/ZNA-1987-42a-0289.pdf
	Identifier	ZNA-1987-42a-0289
	Volume	42

5	Author	J. Krzystek, H.J U C Von Schütz, Wolf, R.-D Stigler, J. J. Stezowski	Requires cookie*
	Title	Characterization of the Phenanthrene-Tetrachlorophthalic Anhydride (P/TCPA) 1:1 Charge-Transfer Crystal: Spectroscopic and Structural Investigations
	Abstract	The 1:1 phenanthrene-tetrachlorophthalic anhydride (P/TCPA) charge-transfer complex crystalizes with monoclinic symmetry, space group P2,, with two magnetically inequivalent stacks in the unit cell. The noncentrosymmetric space group is very unusual for CT-complexes. The optical emission spectra at low temperature are characterized by a strong CT phospho-rescence and a weak CT fluorescence and delayed fluorescence. The S, band lies at 22 800 ± 100 cm" 1 , the T, band at 21 200 ± 100 cm" 1 . Above 15 K triplet excitons, moving along the stacks are revealed by ESR. They have a CT character of about 30%, coinciding with that of the shallow X-traps found by ODMR at jow temperatures. A further trap, with zero-field-splitting (zfs) parameters of £> = ±0.0617, E = + 0.0116 cm" 1 has a much larger CT character of 50% as found in the isolated complex in low-temperature glass [1]. A structural model is proposed.
	Reference	Z. Naturforsch. 42a, 622—630 (1987); received February 28 1987
	Published	1987
	Keywords	Charge-transfer crystal, crystal structure, fluorescence, phosphorescence, triplet excitons
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	TEI-XML for	default:Reihe_A/42/ZNA-1987-42a-0622.pdf
	Identifier	ZNA-1987-42a-0622
	Volume	42

6	Author	U. Eberl, A. Ogrodnik, M. E. Michel-Beyerle	Requires cookie*
	Title	Access to Primary Charge Separation Mechanism in Photosynthetic Reaction Centers: Anisotropic Excitation Spectra of Electric Field Modulated Fluorescence Yields
	Abstract	Two-step sequential and unistep, superexchange primary electron transfer form primary radical pair states which differ in the direction and magnitude of their dipole moments as revealed in the X-ray structure analysis. The direction can be measured by the excitation anisotropy of electric field induced changes of the fluorescence yield. This method determines angles between the dipole of the primary radical pair and photoselected transition moments (in absorption and emission) of cofactors in the reaction centers. Transitions particularly favourable for discrimination between the two models of primary electron transfer are discussed.
	Reference	Z. Naturforsch. 45a, 763—770 (1990); received March 17 1990
	Published	1990
	Keywords	Electric field effect, Anisotropy, Fluorescence, Photosynthesis, Reaction center, Pri-mary charge separation
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	TEI-XML for	default:Reihe_A/45/ZNA-1990-45a-0763.pdf
	Identifier	ZNA-1990-45a-0763
	Volume	45

7	Author	I. Grabchev, I. Moneva, E. Wolarz3, D. Bauman3, S. Stoyanovb	Requires cookie*
	Title	Spectral Properties of 3-Benzanthrone Derivative Dyes in Isotropic Solvents, Polymer Film and Liquid Crystal
	Abstract	Some recently synthesized benzanthrone derivatives bearing azomethine and oxy groups at C-3 po sition have been systematically studied. The influence of the substituents and of the environment (iso tropic and anisotropic media) on the absorption and fluorescence of the dyes and their vibronic transi tions is discussed in this paper.
	Reference	Z. Naturforsch. 56a, 291—296 (2001); received January 24 2001
	Published	2001
	Keywords	3-Benzanthrone Derivatives, Azomethine and Oxy substitutes, Absorption, Fluorescence, Vibronic Structure
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	TEI-XML for	default:Reihe_A/56/ZNA-2001-56a-0291.pdf
	Identifier	ZNA-2001-56a-0291
	Volume	56