Solvent effects on fluorescence spectra decay times and quantum yields of atabrine and its homologs

1978 ◽  
Vol 50 (14) ◽  
pp. 2059-2064 ◽  
Author(s):  
L. J. Cline. Love ◽  
Linda M. Upton ◽  
Arthur W. Ritter
Keyword(s):  
Solvent Effects ◽  
Fluorescence Spectra ◽  
Quantum Yields ◽  
Decay Times

Dye Mixtures for Ultrafast Wavelength Shifters

1994 ◽  
Vol 348 ◽  
Author(s):  
S. Cangopadhyay ◽  
N. Barashkov ◽  
L. Liu ◽  
C. Palsule ◽  
W. Borst ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Fluorescence Spectra ◽  
Continuous Wave ◽  
Quantum Yields ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Epoxy Polymers ◽  
Decay Times ◽  
The Mean ◽  
Coumarin Dyes

ABSTRACTWe have produced fast wavelength shifters using mixtures of various Coumarin dyes with DCM in epoxy-polymers (DGEBA+HHPA) and measured the properties of these wavelength shifters. The particular mixtures were chosen because there is a substantial overlap between the emission spectrum of Coumarin and the absorption spectrum of DCM. The continuous wave and time-resolved fluorescence spectra have been studied as a function of component concentration to optimize the decay times, emission peaks and quantum yields. The mean decay times of these mixtures are in the range of 2.5-4.5 ns. The mean decay time increases with an increase in Coumarin concentration at a fixed DCM concentration or with a decrease in DCM concentration at a fixed Coumarin concentration. This indicates that the energy transfer is radiative at lower relative DCM concentrations and becomes non-radiative at higher DCM concentrations.

Solvent Effects on the Fluorescence Properties of Methyldihydroquinolinones

1991 ◽  
Vol 46 (9) ◽  
pp. 823-828 ◽  
Author(s):  
Snezhana Bakalova
Keyword(s):  
Solvent Effects ◽  
Fluorescence Spectra ◽  
General Type ◽  
Fluorescence Enhancement ◽  
Quantum Yields ◽  
Aprotic Solvents ◽  
Absorption And Fluorescence Spectra ◽  
Solvent Interaction ◽  
Fluorescence Quantum Yields ◽  
Protic Solvents

Abstract The absorption and fluorescence spectra and the fluorescence quantum yields of two methyl-2,3- dihydro-4(1H)-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

Influence of Internal Heavy Atoms on the Spectroscopic Properties of 9-Acetoxy-10-Phenylanthracene Derivatives

1984 ◽  
Vol 39 (10) ◽  
pp. 952-959 ◽  
Author(s):  
Janina R. Heidt
Keyword(s):  
Mirror Symmetry ◽  
Fluorescence Spectra ◽  
Spectroscopic Properties ◽  
Quantum Yields ◽  
Absorption And Fluorescence Spectra ◽  
Fluorescence Quantum Yields ◽  
Heavy Atoms ◽  
Decay Times ◽  
Anthracene Derivatives ◽  
Derivatives Of

Abstract Absorption and fluorescence spectra, fluorescence quantum yields and decay times have been measured for new derivatives of 9-acetoxy-10-acetoxyhalogenophenylanthracene in dioxane. It is found that the strength of the absorption transition decreases with increases atomic number Z of the halogen substituent whereas the strength of the fluorescence transition is constant with the exception for the fluoro-substituted derivatives. The loss of mirror symmetry between the absorption and fluorescence spectra is more evident for the 10-(4-acetoxy-3'-halogenophenyl)anthracene derivatives than for the remaining compounds. The determined nonradiative electronic relaxation rate constant and "dark reactions" quantum yield increases with increasing Z value. These findings are explained on the basis of the spin-orbit coupling enlarged by the heavy substituent and through perturbation of the functional groups, which causes different changes of the molecular geometries in the S0 and S*1 states, respectively.

scholarly journals Indenopyrans – synthesis and photoluminescence properties

2016 ◽  
Vol 12 ◽  
pp. 825-834 ◽  
Author(s):  
Andreea Petronela Diac ◽  
Ana-Maria Ţepeş ◽  
Albert Soran ◽  
Ion Grosu ◽  
Anamaria Terec ◽  
...  
Keyword(s):  
Solid State ◽  
Emission Band ◽  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Band Broadening ◽  
Photoluminescence Properties ◽  
Fluorescence Quantum Yields ◽  
Blue Emitters ◽  
Solid State Fluorescence

New indeno[1,2-c]pyran-3-ones bearing different substituents at the pyran moiety were synthesized and their photophysical properties were investigated. In solution all compounds were found to be blue emitters and the trans isomers exhibited significantly higher fluorescence quantum yields (relative to 9,10-diphenylanthracene) as compared to the corresponding cis isomers. The solid-state fluorescence spectra revealed an important red shift of λmax due to intermolecular interactions in the lattice, along with an emission-band broadening, as compared to the solution fluorescence spectra.

The Synthesis and Electroluminescence Properties of 4-Benzofuranyl-1,8-Naphthalimide Derivatives

2012 ◽  
Vol 557-559 ◽  
pp. 1031-1036 ◽  
Author(s):  
Jian Xin Yang ◽  
Xiang Hui Wang
Keyword(s):  
Absorption Spectra ◽  
Fluorescence Spectra ◽  
Cycloaddition Reaction ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Quantum Yields ◽  
Absorption And Fluorescence Spectra ◽  
Maximum Brightness ◽  
Maximum Emission ◽  
Mild Conditions

A series of fluorescence compounds, 4-benzofuranyl-1,8-naphthalimides, were prepared through cycloaddition reaction from 4-ethynyl-1,8-naphthalimides and o-iodophenols which catalyzed by a Pd(PPh3)2Cl2 / CuI system under mild conditions. The intermediate material, 4-ethynyl-1,8- naphthalimide, was synthesized from 4-bromo-1,8- naphthalimide and trimethylsilyl- acetylene. The absorption and fluorescence spectra of 4-benzofuranyl-1,8- naphthalimides were studied and the quantum yields were measured. The maximum UV/vis absorption spectra were in the range of 375-400 nm and the maximum emission spectra were in the range of 470-510 nm. The electro- luminescent properties were also mensurated through a doped electroluminescent device which contains 1% 1,8-naphthalimides and 99% CBP (4,4'-N,N'-dicarbazole-biphenyl), It’s shown the maximum brightness reached 3700 cd/ m2 at 22.5V.

Study on Photochromic Materials with a Novel Photochromic Diarylethene use for Polarization Holographic Recording

2013 ◽  
Vol 763 ◽  
pp. 61-64 ◽  
Author(s):  
Shang Hua He ◽  
Gang Liu ◽  
Shi Qiang Cui
Keyword(s):  
Fluorescence Spectra ◽  
Uv Light ◽  
Amorphous Film ◽  
Quantum Yields ◽  
Holographic Recording ◽  
Pmma Film ◽  
Recording Medium ◽  
Fluorescent Properties ◽  
Image Recording ◽  
Photochromic Materials

A novel unsymmetrical photochromic diarylethene 1-(2, 5-dimethyl-3-thienyl)-2-[2-methyl-5-(2,2-dibutylfluorene)-3-thienyperfluorocyclo-pentene (1o) was synthesized and its photochromic and fluorescent properties were investigated. Diarylethene 1 changed the color from colorless to hyacinthine upon irradiation with 297 nm UV light, in which absorption maxima were observed at 554 nm in hexane and at 565 nm in PMMA amorphous film, respectively. This new photochromic system also exhibited remarkable fluorescence intensity both in solution and in PMMA film. The fluorescence spectra showed a systematic red-shift with the emission intensity of diarylethene 1 in a photo-stationary state was quenched to ca. 64%. The cyclization and cycloreversion quantum yields of 1 in hexane were determined to be 0.56 and 0.002. Polarization multiplexed image recording can be carried out in this diarylethene 1c/PMMA film as recording medium film.

Fluoreszenz -Untersuchungen an Distyrylbenzolen

1988 ◽  
Vol 43 (6) ◽  
pp. 583-590 ◽  
Author(s):  
Dieter Oelkrug ◽  
Klaus Rempfer ◽  
Ellen Prass ◽  
Herbert Meier
Keyword(s):  
Singlet State ◽  
Fluorescence Decay ◽  
Excited Singlet State ◽  
Quantum Yields ◽  
Excited Singlet ◽  
Fluorescence Quantum Yields ◽  
Forbidden Transition ◽  
Decay Times ◽  
Fluorescence Decay Times

Abstract The absorption and fluorescence of three isomeric distyrylbenzenes are investigated as function of temperature. From the fluorescence decay times and fluorescence quantum yields two classes of oligostyrylarenes can be distinguished. A decisive criterion for this classification is, whether the first excited singlet state S1 belongs to an allowed or forbidden transition S0→S1.

Molecular Vibrations in the Exciton Theory for Molecular Aggregates. V. Electronic Spectra of Weakly-coupled Systems

1963 ◽  
Vol 16 (3) ◽  
pp. 315 ◽  
Author(s):  
EG McRae
Keyword(s):  
Electronic Spectra ◽  
Fluorescence Spectra ◽  
Vibrational Structure ◽  
Coupled Systems ◽  
Quantum Yields ◽  
Molecular Aggregates ◽  
Relative Quantum ◽  
Electronically Excited ◽  
Anthracene Crystal ◽  
Theoretical Results

The theory of the gross vibrational structure in the electronic spectra of molecular aggregates is developed for the case of weak intermolecular interaction. The electronically excited states are represented by a set of m-m functions corrected to first order as described in Part IV of this series. An explicit treatment is given for aggregates with two molecules per unit cell. Formulae are obtained for the relative vibronic intensities, splittings, and polarization ratios in absorption spectra, and for relative quantum yields and polarization ratios in fluorescence spectra. The theoretical results are compared with those of the E-V coupling theory developed in Parts II and III. On the basis of this comparison, a general equation is put forward to relate the theoretical crystal splitting (i.e. the splitting for a rigid model) to observed polarization ratios in spectra. The theoretical results are compared with the observed vibrational structure in the 3800 Ǻ band system of anthracene crystal. The crystal splitting calculated from the observed polarization ratios is 380 cm-1. The theory accounts, within the rather large experimental error, for the observed variations of polarization ratio in both the absorption and the fluorescence spectra of anthracene crystal.

Lumineszenzuntersuchungen zum Problem der Energieübertragung in organischen Molekülkristallen

1970 ◽  
Vol 25 (6) ◽  
pp. 955-966 ◽  
Author(s):  
F. Belitz
Keyword(s):  
Energy Transfer ◽  
Single Crystals ◽  
Fluorescence Spectra ◽  
Dipole Interaction ◽  
Main Process ◽  
Transfer Processes ◽  
Decay Times ◽  
Different Types ◽  
The Mean ◽  
Host Lattices

Abstract From fluorescence spectra and decay times of single crystals of 2.3-dimethylnaphthalene, phenanthrene and p-terphenyl doped with one or two different types of fluorescence molecules (anthracene and, or tetracene) informations about the energy transfer processes are obtained. For doping concentrations smaller than 4·10-4 Mol/Mol the transfer by excitons is the main process. The dipole-dipole interaction over distances more than 80 Å (14 mean molecular distances) can be excluded. The mean travelling distance of the excitons in the three host lattices was found to be 250 - 300 mean molecular distances.

New heterogeneous photosensitizers with phthalocyanine molecules covalently linked to aminopropyl silica gel

2011 ◽  
Vol 15 (07n08) ◽  
pp. 718-726 ◽  
Author(s):  
Nina A. Kuznetsova ◽  
Olga A. Yuzhakova ◽  
Marina G. Strakhovskaya ◽  
Anna O. Shumarina ◽  
Anton S. Kozlov ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Silica Gel ◽  
Fluorescence Spectra ◽  
Quantum Yields ◽  
Absorption And Fluorescence Spectra ◽  
Oxygen Generation ◽  
E Coli ◽  
Singlet Oxygen Generation ◽  
Aqueous Suspensions ◽  
Covalently Linked

New heterogeneous photosensitizers were synthesized, in which phthalocyanines of zinc and aluminum, tetrasubstituted at non-peripheral positions with modified thiophenyl groups, were grafted to aminopropyl silica gel. The absorption and fluorescence spectra, and the quantum yields of fluorescence and photosensitized singlet oxygen generation were estimated for aqueous suspensions of these sensitizers. It is shown that upon photoexcitation, silica gel-bound phthalocyanines produce singlet oxygen and display photobactericidal activity against bacteria E. coli.

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