The Structure of the Long Wave Absorption Edge of Insulating Crystals

1952 ◽  
Vol 65 (1) ◽  
pp. 25-32 ◽  
Author(s):  
I C Cheeseman
Keyword(s):  
Absorption Edge ◽  
Wave Absorption ◽  
Long Wave

The Structure of Polyisoprenes. V. Ultraviolet Absorption Spectra of Certain Carbalkoxy-Substituted 1,5-Dienes, and the Charge-Resonance Spectra of Glutaconic Ester Enolate Ions

1946 ◽  
Vol 19 (1) ◽  
pp. 23-33
Author(s):  
L. Bateman ◽  
H. P. Koch
Keyword(s):  
Absorption Band ◽  
Absorption Spectra ◽  
Special Interest ◽  
Crystalline State ◽  
Marked Change ◽  
Cyanine Dyes ◽  
Structural Type ◽  
Wave Absorption ◽  
Long Wave ◽  
Ester Enolate

Abstract Spectral evidence supports the conclusion reached in Part IV that ring-chain mesomerism in methyl and ethyl Δ1,5-hexadiene-l,1,3,3,4,4,6,6-octacarboxylates is nonexistent in solution, just as in the crystalline state. The data are not inconsistent with chain hyperconjugation in these molecules. The marked change in structural type that follows the addition of one molecule of hydrogen or hydrolytic reagent has been verified spectrographically. The spectra of methyl and ethyl α,γ-dicarboxyglutaconic esters and their sodium and cupric derivatives have been measured in various solvents, and their tautomeric behavior compared with that of other keto-enols. Of special interest is the intense long-wave absorption band of the enolate ions, which are recognized as simple structural analogs of the cyanine dyes giving rise to similar charge-resonance spectra. A preliminary comment is made on the present accepted structure of ethyl 6-ethoxy-α-pyrone-3:5-dicarboxylate.

The Study of Radiation-Induced Instability in the Glassy Arsenic Sulphides by Optical Spectroscopy

2013 ◽  
Vol 200 ◽  
pp. 168-172 ◽  
Author(s):  
Yaroslav Shpotyuk ◽  
Ihor Polovynko
Keyword(s):  
Optical Absorption ◽  
Absorption Edge ◽  
Topological Defects ◽  
Structural Transformations ◽  
Physical Ageing ◽  
Optical Absorption Edge ◽  
Γ Irradiation ◽  
Long Wave ◽  
Radiation Induced ◽  
Complicated Nature

Optical changes caused by 60Co γ-irradiation are studied in glassy-like As40S60. The observed long-wave shift in the range of fundamental optical absorption edge accompanied by increase in transmittance is explained as a manifestation of complicated nature of radiation-induced structural transformations associated with coordination topological defects and additional shrinkage input from natural physical ageing.

Tunable Optical Properties of Ag–TiO2 Nanorod Composites Based on Interparticle Plasmon Coupling

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650110 ◽  
Author(s):  
Yong Zhang ◽  
Fa-Min Liu
Keyword(s):  
Optical Properties ◽  
Reduction Method ◽  
Plasmon Coupling ◽  
Silver Acetate ◽  
Absorption Bands ◽  
Photochemical Reduction ◽  
Wave Absorption ◽  
Long Wave ◽  
Ag Particles ◽  
Tunable Optical Properties

The metal–semiconductor composites with unique optical properties are highly desirable. Here we report that Ag–TiO2 nanorod composites with two distinctive absorption peaks exhibit tunable plasmon coupling behaviors. The intensity of the long-wave absorption could be enhanced by modifying the geometry of TiO2 particles, while such absorption is due to the plasmon coupling between the Ag particles. The long-wave absorption bands can be tuned by varying the reaction time and changing the amount of silver acetate. Furthermore, the Ag–TiO2 composites were also prepared by photochemical reduction method which confirmed the previous properties. These results may help to design metal–semiconductor systems with desirable optical properties.

Directions of the Electronic Absorption Transition Moments in ω-Substituted 4-Dimethylamino-trans-Styrenes

1992 ◽  
Vol 47 (3) ◽  
pp. 471-474 ◽  
Author(s):  
A. Kawski ◽  
Z. Gryczynski ◽  
I. Gryczynski ◽  
J. Kuśba
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption ◽  
Short Wave ◽  
Transition Moment ◽  
Wave Band ◽  
Wave Absorption ◽  
Long Wave ◽  
Transition Moments

a)Absorption transition moment directions of the diphenylphosphinyl (2 a) and methylsulphonyl (3 a) Absorption transition moment directions of the diphenylphosphinyl (2 and methylsulphonyl(3 a) co-substtuted in 4-dimethylamino-trans-styrenes were determined in stretched poylvinyl alcohol(PVA) films based on measurements of the absorption anisotropics. It has been found that thelong-wave absorption spectrum consists of two bands corresponding to differently directed transitionmoments. The transition moment of the intensive long-wave *La band is lies along the long axisof these molecules whereas that of the short-wave band is oriented at (p = 38° for 2 a and q> = 35°for 3 a relative to the transition moment direction of the 1La band-substtuted in 4-dimethylamino-trans-styrenes were determined in stretched poylvinyl alcohol (PVA) films based on measurements of the absorption anisotropics. It has been found that the long-wave absorption spectrum consists of two bands corresponding to differently directed transition moments. The transition moment of the intensive long-wave *La band is lies along the long axis of these molecules whereas that of the short-wave band is oriented at (p = 38° for 2 a and q> = 35° for 3 a relative to the transition moment direction of the 1La band

scholarly journals Ethyne Functionalized Meso-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated Species

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4546
Author(s):  
Eva Molnar ◽  
Emese Gál ◽  
Luiza Găină ◽  
Castelia Cristea ◽  
Luminița Silaghi-Dumitrescu
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Fluorescence Emission ◽  
Soret Band ◽  
Quantum Yields ◽  
Free Base ◽  
Wave Absorption ◽  
Long Wave

Synthesis, structural characterization and photophysical properties for a series of new trans-A2B2- and A3B-type ethynyl functionalized meso-phenothiazinyl-phenyl porphyrin derivatives are described. The new compounds displayed the characteristic porphyrin absorption spectra slightly modified by weak auxochromic effects of the substituents and fluorescence emission in the range of 651–659 nm with 11–25% quantum yields. The changes recorded in the UV-vis absorption spectra in the presence of trifluoroacetic acid (TFA) are consistent with the protonation of the two internal nitrogen atoms of the free-base porphyrin (19 nm bathochromic shift of the strong Soret band and one long wave absorption maxima situated in the range of 665–695 nm). Protonation of the phenothiazine substituents required increased amounts of TFA and produced a distinct hypsochromic shift of the long wave absorption maxima. The density functional theory (DFT) calculations of a porphyrin dication pointed out a saddle-distorted porphyrin ring as the ground-state geometry.

Long-wave absorption and paramagnetism of polymers with conjugated bonds

1973 ◽  
Vol 23 (3) ◽  
pp. 406-408 ◽  
Author(s):  
A.A. Berlin ◽  
G.A. Vinogradov ◽  
A.A. Ovchinnikov
Keyword(s):  
Wave Absorption ◽  
Long Wave

scholarly journals Polymethine Dye as Sensors of NH3 and CO

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Petro O. Kondratenko ◽  
Yuriy M. Lopatkin ◽  
Vita V. Solomko ◽  
Anna G. Malashenko
Keyword(s):  
Light Intensity ◽  
Optical Density ◽  
Absorption Edge ◽  
Inflection Point ◽  
Monochromatic Light ◽  
Polymethine Dyes ◽  
Sensor Layer ◽  
Long Wave ◽  
Hazardous Gases ◽  
Polymethine Dye

We have investigated the properties of polymethine dyes (PMD) and the purpose of using them as sensors of hazardous gases presence. Research indicates that in case of utilizing PMD as a sensor of hazardous gases we need to use the monochromatic light which wavelength corresponds to the inflection point of the long-wave absorption edge of PMD. Such sensor of hazardous gases can detect changes in the optical density of the sensor layer or the light intensity transmitted through the layer.

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