Photochemisches Verhalten und spektroskopische Eigenschaften von Anilino-naphthalinen

1976 ◽  
Vol 31 (8) ◽  
pp. 987-989 ◽  
Author(s):  
F. Fratev ◽  
O.E. Polansky ◽  
M. Zander
Keyword(s):  
Excited State ◽  
Aromatic Amines ◽  
Ring Closure ◽  
Fluorescence And Phosphorescence Spectra ◽  
Fluorescence And Phosphorescence ◽  
Phosphorescence Spectra

AbstractFrom the fluorescence and phosphorescence spectra of several aromatic amines it is concluded that the conjugation between nitrogen and aryl groups in the excited state is restricted. With this result a sterical explanation for the lack of the expected photochemical carbazole ring closure of 1-and 2-anilino naphthalene is given.

Einfluß von Chlorsubstitution auf die El ektronenspektren von Biphenyl

1972 ◽  
Vol 27 (5) ◽  
pp. 756-759 ◽  
Author(s):  
H. Dreeskamp ◽  
O. Hutzinger ◽  
M. Zander
Keyword(s):  
Excited State ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Emission Spectra ◽  
Liquid Solution ◽  
Quantum Yields ◽  
Decay Times ◽  
Fluorescence And Phosphorescence Spectra ◽  
Fluorescence And Phosphorescence ◽  
Phosphorescence Spectra

Abstract Absorption spectra in liquid solution, fluorescence and phosphorescence spectra, phosphores-cence quantum yields, phosphorescence to fluorescence quantum yield ratios, and phosphorescence decay times of 9 chloro substituted biphenyls dissolved in low temperature EPA glass were in-vestigated. The emission spectra of sterically unhindered systems are structured and significantly Stokes-shifted. Ortho substitution shifts the conjugation band in absorption as well as the un-structured fluorescence and phosphorescence bands to shorter wave lengths presumably by pre-venting the system from attaining a planar excited state. Chloro substitution which increases the rate constant of phosphorescence in the order meta < para < ortho, is nearly additive for multiple substituted systems and is correlated to the MO coefficients at the chloro substituted position in the absence of steric hindrance

Electrochemiluminescence of carbazole

1969 ◽  
Vol 47 (8) ◽  
pp. 1355-1359 ◽  
Author(s):  
K. S. V. Santhanam ◽  
R. N. O'Brien ◽  
A. D. Kirk
Keyword(s):  
Excited State ◽  
Emission Spectrum ◽  
Supporting Electrolyte ◽  
Ammonium Iodide ◽  
Process Comparison ◽  
Fluorescence And Phosphorescence Spectra ◽  
Fluorescence And Phosphorescence ◽  
Phosphorescence Spectra

Effect of supporting electrolytes in the electrochemiluminescence of carbazole has been studied with a view to understanding more about the mechanism of the chemiluminescence process. Comparison of the emission spectrum with its fluorescence and phosphorescence spectra suggests that the excited state is not carbazole. The intense chemiluminescence observed with tetra-n-butyl ammonium iodide as supporting electrolyte has been examined.

A NOVEL GREEN LONG-LASTING PHOSPHOR Ca2ZnSi2O7:Eu2+

2011 ◽  
Vol 04 (03) ◽  
pp. 289-293 ◽  
Author(s):  
WEI ZENG ◽  
YUHUA WANG ◽  
XUHUI XU ◽  
YU GONG
Keyword(s):  
High Temperature ◽  
Zinc Vacancy ◽  
Solid State Method ◽  
Naked Eye ◽  
State Method ◽  
Relationship Of ◽  
The Relationship ◽  
Fluorescence And Phosphorescence Spectra ◽  
Fluorescence And Phosphorescence ◽  
Phosphorescence Spectra

A new green emitting long-lasting phosphor Ca2ZnSi2O7:Eu2+ has been synthesized through the high temperature solid-state method. The excitation spectrum of [Formula: see text] shows a broadband attributed to 8S7/2–4f65d1 transition of Eu2+ ions. Both of the fluorescence and phosphorescence spectra showed a broadband centered at 528 nm, corresponding the only one Ca2+ site in Ca2ZnSi2O7 . The relationship of emission wavelength and Eu–O distance is investigated. Its afterglow can be seen with the naked eye in the dark clearly for 2 h after removal of the excitation source. Oxygen vacancy [Formula: see text] and zinc vacancy [Formula: see text], two different kinds of traps are proposed and their contrary influence on afterglow is discussed.

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