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.

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.

scholarly journals On the fluorescence and channelled absorption spectra of cæsium and other alkali elements

1923 ◽  
Vol 103 (721) ◽  
pp. 304-314 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Fluorescence Spectrum ◽  
Absorption Spectra ◽  
Wave Length ◽  
Monochromatic Light ◽  
Exciting Light ◽  
Absorption Bands ◽  
The Mean ◽  
Alkali Elements ◽  
Different Sources

In 1874 it was shown by Roscoe and Schuster that channelled absorption spectra can be obtained with the vapours of the alkali elements sodium and potassium, and later on these spectra were investigated in some detail by Liveing and Dewar. It was also shown in 1896 by Weidemann and Schmidt that the vapours of these same metals emitted a radiation possessing characteristics of a fluorescence spectrum when they were traversed by white light. Since 1903 exhaustive studies have been made of both the fluorescence and the channelled absorption spectrum of sodium by R. W. Wood, together with a number of collaborators, Including J. H. Moore and F. E. Hackett. In these investigation it was shown that the channelled absorption spectrum of sodium was made up of a number of series of absorption bands, one set of series being on the red wave-length side of the D lines, and another lying in the visible blue-green region. In addition, series of absorption bands were found by them with approximately regular spacing in the neighbourhood of λ = 3303 A, the second member of the doublet series of this element. As regards the fluorescence spectrum of sodium, they found that, by stimulation of the vapour with approximately monochromatic light, there resulted an emission of light, the spectrum of which consisted of a number of bright but narrow bands of varying intensity, more or less regularly spaced both above and below the mean wave-length of the exciting light. They observed, too, that the slightest change in the wave-length of the exciting light resulted in the disappearance of one set of lines and in the appearance of another of different wave-lengths. In the various florescence spectra obtained by R. W. Wood when stimulating sodium vapour by monochromatic light from different sources, it was noted that there was a remarkable recurrence of the interval, ∆ λ = 52·3 A. in the spacing of the fluorescence bands.

Molecular Vibrations in the Exciton Theory for Molecular Aggregates. II. Dimeric Systems

1961 ◽  
Vol 14 (3) ◽  
pp. 344 ◽  
Author(s):  
EG McRae
Keyword(s):  
Absorption Spectrum ◽  
Perturbation Theory ◽  
Fluorescence Spectra ◽  
Numerical Calculations ◽  
Molecular Vibrations ◽  
Molecular Aggregates ◽  
Absorption And Fluorescence Spectra ◽  
Band Structures ◽  
Electronic Band ◽  
Electronic Band Structures

The theory of Part I of this series (McRae 1961) is developed in detail for dimeric systems. The simplest possible theory of the exciton states for a system of two non-rigid molecules is obtained through the use of perturbation theory. The theory makes possible the prediction of electronic band structures in absorption and fluorescence spectra as functions of the theoretical Davydov splitting for two rigid molecules. Numerical calculations are made for a dimer of a typical dye, and the results are compared with the observed absorption spectrum of the 1,1'-diethyl-2,2'-pyridocyanine iodide dimer.

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.

scholarly journals The absorption spectra of halogens and inter-halogen compounds in solution in carbon tetrachloride

1929 ◽  
Vol 124 (795) ◽  
pp. 604-616 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Carbon Tetrachloride ◽  
Absorption Spectra ◽  
Spectroscopic Data ◽  
Chemical Interaction ◽  
Chemical Compounds ◽  
Absorption Bands ◽  
Halogen Compounds ◽  
Inert Solvent ◽  
The Mean

When two solutions are mixed the absorption spectrum of the new solution will be the mean of those of the separate solutions provided that no chemical interaction occures. The mere fact of a departure from additivity does not, however, necessarily denote the formation of true chemical compounds. The solute or solutes may undergo solvation, loosely bound aggregates may occur, and even when marked deviations from the simple law of mixtures are observed it is rarely possible to prove the quantitative formation of a given chemical compound from spectroscopic data alone. The above considerations apply with some force to the problem of the absorption spectra of halogens and inter-halogen compounds in an inert solvent. The three elements show perfectly characteristic absorption bands, they are known to interact with the formation of some quite stable compounds, some relatively stable compounds, and some apparently very unstable compounds.

The A2Πi–X2Πi absorption spectrum of BrO

1981 ◽  
Vol 59 (12) ◽  
pp. 1908-1916 ◽  
Author(s):  
M. Barnett ◽  
E. A. Cohen ◽  
D. A. Ramsay
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Ground State ◽  
Flash Photolysis ◽  
Absorption Bands ◽  
Long Wavelength ◽  
Numbering Scheme ◽  
Ozonized Oxygen ◽  
Good Agreement

Absorption spectra of isotopically enriched 81Br16O and of normal BrO have been obtained by the flash photolysis of mixtures of bromine and ozonized oxygen. Rotational analyses are given for the 7–0, 12–0, 18–0, 19–0, 20–0, 21–0, 7–1, and 20–1 A2Π3/2–X2Π3/2 sub-bands of 81Br16O. The value for [Formula: see text] is found to be 722.1 ± 1.1 cm−1 in good agreement with the value calculated from microwave constants. Several additional bands have been found at the long wavelength end of the spectrum, necessitating a revision of the vibrational numbering scheme for both the emission and absorption bands. "Hot" bands up to ν″ = 6 have been observed in the absorption spectrum for the 2Π3/2 component of the ground state but no bands have yet been identified from the 2Π1/2 component.

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 The absorption spectra of conjugated dienes in the vacuum ultra-violet (1)

1940 ◽  
Vol 174 (957) ◽  
pp. 220-234 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Electronic Structures ◽  
Spectroscopic Data ◽  
Ultra Violet ◽  
Conjugated Dienes ◽  
Strong Absorption ◽  
Absorption Bands ◽  
Lennard Jones ◽  
Vacuum Ultra Violet

Butadiene is important as the simplest example of resonance between two conjugated double bonds. The comparison of its ultra-violet absorption spectrum with that of ethylene might be expected to give some indication of the way the π electrons of the molecule are affected by the resonance. The electronic structures of a number of molecules for which resonance is important have been worked out theoretically by Hückel (1935), Lennard- Jones (1937), Sklar (1937) and Mulliken (1939 a and b ). The purpose of the present work is to obtain spectroscopic data with which the theoretical expectations can be compared. As most of the strong absorption bands of these molecules occur at wave-lengths less than 2000 A, the investigation falls naturally into the region of vacuum spectroscopy.

Spectroelectrochemical Study of some μ3-Oxo-μ-acetato Trinuclear Rhodium(III) and Iridium(III) Complexes

1995 ◽  
Vol 50 (4) ◽  
pp. 551-557 ◽  
Author(s):  
Kenta Takahashi ◽  
Keisuke Umakoshi ◽  
Akihiro Kikuchi ◽  
Yoichi Sasaki ◽  
Masato Tominaga ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Visible Region ◽  
Absorption Bands ◽  
Visible Absorption ◽  
The One ◽  
Species Being

New trinuclear rhodium(III) complexes, [Rh3(μ3-O)(μ-CH3COO)6(L)3]+ (L = imidazole (Him), 1-methylimidazole (Meim), and 4-methylpyridine (Mepy)) have been prepared. The Him, Meim, and Mepy complexes show reversible one-electron oxidation waves at E1/2 = +1.12, +1.12, and +1.28 V vs Ag/AgCl, respectively, in acetonitrile. Electronic absorption spectra of the one electron oxidized species of these complexes and [Rh3(μ3-O)(μ-CH3COO)6(py)3]+ (py = pyridine) (E1/2 = +1.32 V ) were obtained by spectroelectrochemical techniques. While the Rh3(III,III,III) states show no strong visible absorption, the Rh3(III,III,IV ) species give a band at ca. 700 nm (ε = 3390-5540 mol dm-3 cm-1). [Ir3(μ3-O)(μ-CH3COO)6(py)3]+ with no strong absorption in the visible region, shows two reversible one-electron oxidation waves at +0.68 and +1.86 V in acetonitrile. The electronic absorption spectrum of the one-electron oxidized species (Ir3(III,III,IV )) also shows some absorption bands (688 nm (ε, 5119), 1093 (2325) and 1400 (ca. 1800)). It is suggested that the oxidation removes an electron from the fully occupied anti-bonding orbital based on metal-dπ-μ3-O-pπ interactions, the absorption bands of the (III,III,IV ) species being assigned to transitions to the anti-bonding orbital.

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