Long-wave absorption band and magnetic susceptibility of nickel phthalocyanine in relation to its degree of oxidation

1990 ◽  
Vol 25 (5) ◽  
pp. 494-498
Author(s):  
A. G. Vinogradskii
Keyword(s):  
Magnetic Susceptibility ◽  
Absorption Band ◽  
Wave Absorption ◽  
Nickel Phthalocyanine ◽  
Long Wave ◽  
Degree Of Oxidation

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.

On the Determination of Transition-Moment Directions from Absorption Anisotropy Measurements

1987 ◽  
Vol 42 (6) ◽  
pp. 617-621 ◽  
Author(s):  
A. Kawski ◽  
Z. Gryczyński
Keyword(s):  
Absorption Band ◽  
Polymer Film ◽  
Stretch Ratio ◽  
Transition Moment ◽  
Molecular Axis ◽  
Small Deviations ◽  
Wave Absorption ◽  
Long Wave ◽  
Absolute Transition

A formula is derived for the absorption anisotropy K = (A∥ - A⊥) / (A∥ + 2A⊥ ) (where A∥ and A⊥ are the absorbances parallel and perpendicular to the stretching direction of the polymer film, respectively) as a function of the stretch ratio, Rs, of the film and the angle φ between the absorption transition moment direction and the long axis of a prolate molecule. Employing this relation, absolute transition moment directions (the angles φ) were determined experimentally for the following compounds: 1.8-diphenyloctatetraene (DPO), 1,6-diphenylhexatriene (DPH), 1.4-diphenylbutadiene (DPB), 4-dimethylamino-4'-nitrostilbene (DNS), 4-dimethylamino- 4'-chlorostilbene (DCIS) and p-terphenyl (TP). The directions were found to be along the long molecular axis in the long-wave absorption band. Small deviations of the angles obtained from (φ= 0°, which were of the order of several degrees, are due to the incomplete linearity of the molecules under investigation.

scholarly journals On the Determination of Transition-Moment Directions from Emission Anisotropy Measurements

1986 ◽  
Vol 41 (10) ◽  
pp. 1195-1199 ◽  
Author(s):  
A. Kawski ◽  
Z. Gryczyński
Keyword(s):  
Absorption Band ◽  
Polymer Film ◽  
Transition Moment ◽  
Emission Anisotropy ◽  
Wave Absorption ◽  
Long Wave ◽  
Linear Trans

Based on the theory of photoluminescence polarization, a description of the determination of transition-moment directions in luminescent molecules oriented in a stretched polymer film is given. This method is applied to the linear trans-diphenylpolyenes (C2h symmetry): 1,8-diphenyloctatetraene (DPO ), 1,6-diphenylhexatriene (DPH) and 1,4-diphenylbutadiene (DPB). The same transition moment polarized along the long axis o f DPO , DPH and DPB is responsible for absorption and fluorescence (β ≈ 0), when exciting in the long wave absorption band. The results are compared with relevant data obtained from dichroism measurements.

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

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