scholarly journals Optical properties of fully conjugated cyclo[n]thiophenes – An experimental and theoretical approach

2011 ◽  
Vol 2 ◽  
pp. 720-726 ◽  
Author(s):  
Elena Mena-Osteritz ◽  
Fan Zhang ◽  
Günther Götz ◽  
Peter Reineker ◽  
Peter Bäuerle
Keyword(s):  
Optical Properties ◽  
Absorption Spectra ◽  
Theoretical Approach ◽  
Fluorescence Spectra ◽  
Frenkel Exciton ◽  
Absorption And Fluorescence Spectra ◽  
Ring Strain

Optical properties of two series of fully conjugated cyclo[n]thiophenes were analyzed experimentally and theoretically. The absorption spectra reveal a shift to higher wavelengths with increasing size of the cycles, which can be successfully described by an excitonic approach based on a Frenkel exciton Hamiltonian. Furthermore, intriguing new bands in the absorption and fluorescence spectra of the smaller macrocycles disclose the dominance of their ring strain.

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.

Electronic Spectroscopy of Mixed Cyclophanes: [2.2](9,10)Anthracenometacyclophane, [2.2](9,10) and [3.3](9,10)-Anthracenoparacyclophane

1989 ◽  
Vol 42 (12) ◽  
pp. 2215 ◽  
Author(s):  
J Ferguson ◽  
M Puza ◽  
RJ Robbins ◽  
GJ Wilson
Keyword(s):  
Absorption Spectra ◽  
Strong Interaction ◽  
Fluorescence Spectra ◽  
Electronic Spectroscopy ◽  
Absorption And Fluorescence Spectra ◽  
Absorption Bands

The absorption and fluorescence spectra of the title compounds are reported and a simple coupled chromophore model has been used to make assignments of the absorption bands. The absorption spectra show a strong interaction between the 1Lb state of the anthracene chromophore and the 1Lb state of the benzene chromophore in both anthracenoparacyclophanes which is absent in [2.2](9,10) anthracenometacyclophane. The fluorescence comes from the 1La state of the anthracene chromophore.

Optical Properties of 5,5'-(9,9-dioctyl-9H-fluorene-2,7-diyl)Bis(thiophene-2-carbal dehyde): A Novel Organic Light Emitting Material

2014 ◽  
Vol 941-944 ◽  
pp. 662-665
Author(s):  
Ze Biao Tang ◽  
Xiao Xia Sun ◽  
He Wei Yan ◽  
Le Ping Miao
Keyword(s):  
Optical Properties ◽  
Blue Light ◽  
Fluorescence Spectra ◽  
Aldehyde Group ◽  
Organic Light Emitting Diodes ◽  
Target Compound ◽  
Absorption And Fluorescence Spectra ◽  
Light Emitting ◽  
Organic Light ◽  
Type Molecule

A novel D-A type molecule based on central fluorene unit and aldehyde group termini has been designed and constructed. Optical spectra show that, from the solution to the solid state, the absorption and fluorescence spectra of the compounds are red-shifted. Moreover, a red-shift of the absorbance maxima and the emission maxima of the compounds were observed due to the electron-accepting groups. Blue light-emitting properties with purity color range at 412–468 nm were also obtained. Thus, the target compound is expected to be a promising pure blue light-emitting material for applications in organic light-emitting diodes (OLEDs).

scholarly journals Synthesis, solvatochromism, electronic structure and nonlinear optic properties of quinolin-8-yl 2-hydroxybenzoate

2018 ◽  
Vol 37 (2) ◽  
Author(s):  
Ayşegül Gümüş ◽  
Yadigar Gülseven Sıdır ◽  
İsa Sıdır ◽  
Selçuk Gümüş
Keyword(s):  
Hydrogen Bonding ◽  
Electronic Structure ◽  
Absorption Spectra ◽  
Potential Energy Surfaces ◽  
Fluorescence Spectra ◽  
Solvent Polarity ◽  
Specific Interactions ◽  
Absorption And Fluorescence Spectra ◽  
Stable Conformer ◽  
Computational Calculations

Quinolin-8-yl-2-hydroxybenzoate (abbreviated as QHB) was synthesized and investigated both experimentally and theoretically to obtain its physical and electronic properties. The electronic structure and spectral behavior have been determined by using UV-vis absorption and fluorescence spectra in different 11 polarity solvent medium. The absorption band observed at 306 nm-308 nm is found to having mix of π-π* and n-π* electronic transitions due to its geometrical structure in the solution phase. Solvatochromism of QHB is investigated by using Kamlet-Taft and Catalan methods based on the linear solvation energy relationships (LSER). Kamlet-Taft solvatochromic model indicates that spectral shifts of absorption and fluorescence spectra are effectively controlled by dispersion-polarization forces which describe the non-specific interactions. Solvatochromic model of Catalan designates that solute-solvent interaction is governed by solvent polarity in the absorption spectra and by solvent acidity in the fluorescence spectra. Non-specific interactions have greater effect on fluorescence spectra compared to absorption spectra. Computational calculations were performed by the application of B3LYP/6-311+(d,p) level of theory. Conformational analysis is performed for QHB and five staggered conformers are observed on torsional potential energy surfaces. Accordingly, the most stable conformer is found as involving intra-molecular hydrogen bonding. The geometry of the other conformers indicates that the absence of hydrogen bonding gives rise to relatively higher energy.  Frontier molecular orbitals (HOMO, LUMO) and non-linear optical (NLO) parameters have been calculated by B3LYP/6-311+(d,p) level of theory. Theoretical UV spectra both in gas and solution phases have also been investigated by TDDFT-CAM-B3LYP/6-311+(d,p) level of theory.

scholarly journals Modeling the optical properties of excitons in linear and tubular J-aggregates

2006 ◽  
Vol 2006 ◽  
pp. 1-10 ◽  
Author(s):  
Jasper Knoester
Keyword(s):  
Optical Properties ◽  
Fluorescence Spectra ◽  
Light Harvesting ◽  
Cyanine Dyes ◽  
Natural Light ◽  
Artificial Light ◽  
Absorption And Fluorescence Spectra ◽  
Harvesting Systems ◽  
J Aggregates ◽  
Frenkel Excitons

The theory of the optical properties of linear and tubular molecular J-aggregates is reviewed. The primary optical excitations in these systems are Frenkel excitons, which may be delocalized over many molecules. The collective nature of these excitations gives rise to special optical properties and dynamics, which are of interest for purely scientific reasons, but also enable the application of J-aggregates as photographic sensitizers and artificial light-harvesting systems. The focus of this paper is on the effect of aggregate geometry, disorder, and temperature on the absorption and fluorescence spectra. Also transport of excitations between J-aggregates is discussed. Connection is made to experiments on aggregates of cyanine dyes and natural light-harvesting systems.

Electronic Spectroscopy of Mixed Cyclophanes: [2.2](9,10)Anthraceno(1,4)naphthalenophane

1989 ◽  
Vol 42 (12) ◽  
pp. 2201 ◽  
Author(s):  
J Ferguson ◽  
RJ Robbins ◽  
GJ Wilson
Keyword(s):  
Absorption Spectrum ◽  
Single Crystal ◽  
Fluorescence Spectrum ◽  
Absorption Spectra ◽  
Fluorescence Polarization ◽  
Fluorescence Spectra ◽  
Electronic Spectroscopy ◽  
Absorption And Fluorescence Spectra ◽  
Absorption Bands ◽  
Absorption Intensity

The absorption and fluorescence spectra of [2.21(9,10) anthraceno (1,4) naphthalenophane are reported. The anisotropy of the absorption bands was measured by two methods, ( i ) from fluorescence polarization ratios in a rigid glass and (ii) from single crystal absorption spectra at 23 K. The two states arising from the 1La states of the two chromophores were identified together with two states arising from other chromophore 1B2u states. Two states arising from the 1La states of the two chromophores were also identified. Whereas a coupled chromophore model accounts reasonably well for the latter two states, the energies and intensities of the bands arising from 1La chromophore states cannot be reconciled with this approach. Long axis polarized absorption intensity lying under the 1La, bands appears to be vibronically induced and not due to the 1Lb states. The absorption spectrum, fluorescence spectrum and fluorescence polarization ratios of a stable dimer were also observed. Its structure is similar to that of the stable dimer of anthracene in which the molecular long axes are parallel but the short axes make an angle of about 70� with each other.

Synthesis and optical properties of trifluoroethoxy-substituted double-decker phthalocyanines

2014 ◽  
Vol 18 (10n11) ◽  
pp. 1034-1041 ◽  
Author(s):  
Satoru Mori ◽  
Naoya Ogawa ◽  
Etsuko Tokunaga ◽  
Norio Shibata
Keyword(s):  
Optical Properties ◽  
Steric Hindrance ◽  
Fluorescence Spectra ◽  
Absorption And Fluorescence Spectra ◽  
Double Decker ◽  
First Time

The synthesis of trifluoroethoxy-substituted double-decker phthalocyanines was investigated for the first time. Trifluoroethoxy-substituted phthalonitriles reacted with lanthanide acetylacetonate hydrate in n-octanol in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene when refluxed. La and Eu were chosen as central metals. Phthalonitriles, including one trifluoroethoxy substituent at the α- or β-position, were nicely induced to double-decker phthalocyanines. Phthalonitrile having two trifluoroethoxy substituents at α-positions did not react, although we succeeded in leading β-di-substituted phthalonitrile to double-decker phthalocyanines. Fully trifluoroethoxy-coated phthalonitrile did not react at all. Fluorophobic repulsion and steric hindrance caused by outlying trifluoroethoxy groups could be responsible for the difficulty in the formation of a double-decker structure. Absorption and fluorescence spectra of trifluoroethoxy-substituted double-decker phthalocyanines obtained were also investigated.

Degradation of Ru(bpy)32+-based OLEDs

2004 ◽  
Vol 846 ◽  
Author(s):  
Velda Goldberg ◽  
Michael Kaplan ◽  
Leonard Soltzberg ◽  
Joseph Genevich ◽  
Rebecca Berry ◽  
...  
Keyword(s):  
Optical Properties ◽  
Mass Spectra ◽  
Fluorescence Spectra ◽  
Electrochemical Process ◽  
Water Molecules ◽  
Absorption And Fluorescence Spectra ◽  
Electrical And Optical Properties ◽  
Maldi Tof ◽  
Maldi Tof Mass Spectra ◽  
Overall Efficiency

ABSTRACTAnalysis of the possible mechanisms of degradation of Ru(bpy)32+-based OLEDs has led to the idea of quencher formation in the metalloorganic area close to the cathode. It has been suggested that the quencher results from an electrochemical process where one of the bipyridine (bpy) groups is replaced with two water molecules [1] or from reduction of Ru(bpy)32+ to Ru(bpy)30 [2]. We have tested these and other degradation ideas for Ru(bpy)32+-based OLEDs, both prepared and tested with considerable exposure to the ambient environment and using materials and procedures that emphasize cost of preparation rather than overall efficiency. In order to understand the mechanisms involved in these particular devices, we have correlated changes in the devices' electrical and optical properties with MALDI-TOF mass spectra and UV-vis absorption and fluorescence spectra.

scholarly journals The Establishment of a Theoretical Model for the Estimation of Some Photo-Physical Processes in Laser Dyes

2020 ◽  
pp. 780-790
Author(s):  
Husam S. Al-Arab ◽  
Mahasin F. H. Al-Kadhemy ◽  
Asrar Abdulmunem Saeed
Keyword(s):  
Titanium Dioxide ◽  
Tio2 Nanoparticles ◽  
Absorption Spectra ◽  
Fluorescence Spectra ◽  
Titanium Dioxide Nanoparticles ◽  
Theoretical Method ◽  
Experimental Measurements ◽  
Laser Dyes ◽  
Absorption And Fluorescence Spectra ◽  
Fluorescein Dye

In this study, a new theoretical method for the estimation of absorption and fluorescence spectra is accomplished. These estimations were established following experimental measurements of absorption and fluorescence spectra for the solutions of fluorescein laser dye mixed with titanium dioxide (TiO2) nanoparticlesin distilled water. The used concentration of fluorescein dye was 1x10-5 M, whereas the masses of titanium dioxide nanoparticles were 0.0003g, 0.0005g, 0.001g and 0.002g. An absorption spectra improvement was observed upon raising the mass of TiO2 nanoparticles, which specifies that doping the fluorescein dye with TiO2 nanoparticles have an essential influence on the dye absorption spectra. On the other side, all fluorescence spectra for the dye quenched as TiO2 nanoparticles mass was increased, because of the induced electron transfer. The new method of theoretical estimations was based on curve fitting using Logistic Power Peak (LPP) function to estimate theoretical models for the absorption and fluorescence spectra of thesesamples. The results revealed that these estimated models had exceptional matching shapes with the experimental shapes, so that the estimated models can substitute the experimental measurements.

scholarly journals Study the Optical and Spectral Properties of the Acridine Dye As an Effective Medium in Dye Lasers

2018 ◽  
Vol 26 (10) ◽  
pp. 167-180
Author(s):  
Afrah M. AL Hussainey ◽  
Ruaa Kahtan Mahmoud ◽  
Talib M. Abbas ALShafie
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Emission Spectrum ◽  
Spectral Properties ◽  
Fluorescence Spectra ◽  
Spectral Characteristics ◽  
Dye Lasers ◽  
Intensity Increase ◽  
Absorption And Fluorescence Spectra

         In this study, the absorption and fluorescence spectra of the dissolved Acridine solution were studied in ethanol and different concentrations. The optical properties (absorption coefficient, linear refraction) and spectral characteristics (Fluorescence time and quantitative fluoridation efficiency) were calculated. It is observed that increasing the concentration increases the absorbance values and decreases the permeability values, thus increasing the values of the absorption coefficient and the refractive index. Also, the values of the fluorine intensity increase. The peak of the emission spectrum is transferred to the longer wavelengths.                                                                                                                    

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