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.

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.

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.

Synthesis and photophysical properties of zinc phthalocyanines substituted with quinolinoxy group

2009 ◽  
Vol 13 (12) ◽  
pp. 1206-1213 ◽  
Author(s):  
Jinping Xue ◽  
Lixuan Cai ◽  
Naisheng Chen ◽  
Jinling Huang
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Elemental Analysis ◽  
Fluorescence Spectra ◽  
Electronic Absorption Spectra ◽  
Photophysical Properties ◽  
Electronic Spectroscopy ◽  
Zinc Phthalocyanines ◽  
New Compounds ◽  
First Time

The synthesis of tetrasubstituted zinc phthalocyanines bearing quinolinoxy groups are reported for the first time. The new compounds have been characterized by elemental analysis, IR, MS and electronic spectroscopy. The photophysical properties, such as the electronic absorption spectra and fluorescence spectra, have also been investigated and discussed together with the influence of substituent position and organic solvents on these properties. The introduction of quinolinoxy group to the Pc ring was found to affect these photophysical properties to some extent.

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.

Electronic Spectroscopy of a C7H4+ Isomer in a Neon Matrix: Methyltriacetylene Cation

2014 ◽  
Vol 67 (3) ◽  
pp. 416 ◽  
Author(s):  
Arghya Chakraborty ◽  
Jan Fulara ◽  
John P. Maier
Keyword(s):  
Fluorescence Spectra ◽  
Spectroscopic Analysis ◽  
Laser Excitation ◽  
Electronic Spectroscopy ◽  
Ion Source ◽  
Electronic Transitions ◽  
Mass Selection ◽  
Absorption And Fluorescence Spectra ◽  
Excitation Energies ◽  
Vibrational Bands

Absorptions commencing at 602.6 nm are detected following deposition of mass-selected C7H4+ in a 6 K neon matrix produced from a 1 : 1 mixture of diacetylene and propyne in an ion source. The 602.6 nm system, and a weaker one near 421.1 nm, are assigned to the A 2E ← X 2E and B 2E ← X 2E electronic transitions of methyltriacetylene cation (C3V symmetry), based on mass-selection, spectroscopic analysis of the vibrational structure, and the excitation energies calculated with CASPT2. Structured fluorescence is detected in the 600–760 nm range upon laser excitation at wavelengths of the CH3C6H+ absorptions. The vibrational bands observed in the absorption and fluorescence spectra are assigned with the aid of calculated frequencies of the totally symmetric (a1) vibrations of methyltriacetylene cation.

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 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.

Mechanism of anionic coordination dimerization of isoprene

1981 ◽  
Vol 46 (7) ◽  
pp. 1600-1606 ◽  
Author(s):  
Jan Bartoň ◽  
Karel Volka ◽  
Miroslav Kašpar ◽  
Vlastimil Růžička
Keyword(s):  
Gas Chromatography ◽  
Alkali Metal ◽  
Absorption Spectra ◽  
Visible Radiation ◽  
Absorption Bands ◽  
Absorption Spectrophotometry ◽  
Spectrophotometric Data ◽  
Oligomeric Forms

The mechanism of controlled anionic coordination dimerization of isoprene (i.e. 2-methyl-1,3-butadiene) in the system tetrahydrofuran-isoprene-alkali metal-dialkylamine was investigated by using absorption spectrophotometry in the range of visible radiation and gas chromatography. The effect of the alkali metal (Li, Na, K) and dialkylamine (dicyclohexylamine, N-isopropylcyclohexylamine, N-methylisopropylamine) on the absorption spectra was tested. By comparing chromatographic and spectrophotometric data, the absorption bands in the range of visible radiation were identified with the existence of π-complexes between oligomeric forms of isoprene and alkali metal dialkylamide.

scholarly journals Unraveling the electrochemical and spectroscopic properties of neutral and negatively charged perylene tetraethylesters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christian Wiebeler ◽  
Joachim Vollbrecht ◽  
Adam Neuba ◽  
Heinz-Siegfried Kitzerow ◽  
Stefan Schumacher
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Energy Levels ◽  
Spectroscopic Properties ◽  
Absorption Bands ◽  
Functional Theory ◽  
Vertical Excitation ◽  
Hartree Fock ◽  
Tauc Plot ◽  
Electrochemical Approach

AbstractA detailed investigation of the energy levels of perylene-3,4,9,10-tetracarboxylic tetraethylester as a representative compound for the whole family of perylene esters was performed. It was revealed via electrochemical measurements that one oxidation and two reductions take place. The bandgaps determined via the electrochemical approach are in good agreement with the optical bandgap obtained from the absorption spectra via a Tauc plot. In addition, absorption spectra in dependence of the electrochemical potential were the basis for extensive quantum-chemical calculations of the neutral, monoanionic, and dianionic molecules. For this purpose, calculations based on density functional theory were compared with post-Hartree–Fock methods and the CAM-B3LYP functional proved to be the most reliable choice for the calculation of absorption spectra. Furthermore, spectral features found experimentally could be reproduced with vibronic calculations and allowed to understand their origins. In particular, the two lowest energy absorption bands of the anion are not caused by absorption of two distinct electronic states, which might have been expected from vertical excitation calculations, but both states exhibit a strong vibronic progression resulting in contributions to both bands.

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