Electronic absorption and luminescence spectroscopic studies of kyanite single crystals: differentiation between excitation of FeTi charge transfer and Cr 3+ dd transitions

1998 ◽  
Vol 25 (3) ◽  
pp. 203-212 ◽  
Author(s):  
A. N. Platonov ◽  
A. N. Tarashchan ◽  
K. Langer ◽  
M. Andrut ◽  
G. Partzsch ◽  
...  
1980 ◽  
Vol 35 (10) ◽  
pp. 1013-1019 ◽  
Author(s):  
Friedrich Seitz ◽  
Terence E. Wood ◽  
Peter Day

Abstract Electronic absorption spectra are reported for single crystals of composition FexCo1-xCl2 as a function of temperature from 300 K to 4 K. A broad band at 436 nm is assigned to Fe (II) → Co (II) charge transfer and the temperature dependence of its intensity is related to the magnetic exchange between the ions. The 2T1g(2H) excitation of Co (II) in the mixed crystals has an unusual temperature dependence which correlates with the Néel temperature.


1969 ◽  
Vol 23 (3) ◽  
pp. 254-256 ◽  
Author(s):  
A. Mustafa ◽  
R. Abu-Eittah ◽  
S. Elgendi

The electronic absorption spectra of some drugs derived from p-amino benzoic acid were studied. The effect of the substituent on the position of band maxima and intensity has been rationalized. Long wavelength energies have been found to agree well with calculated energies of the intramolecular charge transfer bands.


1972 ◽  
Vol 26 (2) ◽  
pp. 270-277 ◽  
Author(s):  
R. H. Abu-Eittah ◽  
R. H. Hilal

The electronic absorption spectra of some derivatives of benzenethiol were studied in the visible-ultraviolet regions in a number of solvents. Solvent effects on the position of band maxima helped in identifying the different types of transitions obtained, namely n → π*, π → π*, and intramolecular charge transfer transitions. Energies of the charge transfer bands were computed theoretically and agreed well with the experimental results. Transition probability coefficients and oscillator strength were calculated for the different transitions. Numerical values of the oscillator strength helped to differentiate between the various types of transitions.


2021 ◽  
Vol 22 (9) ◽  
pp. 4803
Author(s):  
Eduardo Gomez ◽  
Ichiro Hisaki ◽  
Abderrazzak Douhal

Hydrogen-bonded organic frameworks (HOFs) are the focus of intense scientific research due their potential applications in science and technology. Here, we report on the synthesis, characterization, and photobehavior of a new HOF (T12F-1(124TCB)) based on a dehydrobenzoannulene derivative containing fluorine atoms (T12F-COOH). This HOF exhibits a 2D porous sheet, which is hexagonally networked via H-bonds between the carboxylic groups, and has an interlayers distance (4.3 Å) that is longer than that of a typical π–π interaction. The presence of the fluorine atoms in the DBA molecular units largely increases the emission quantum yield in DMF (0.33, T12F-COOH) when compared to the parent compound (0.02, T12-COOH). The time-resolved dynamics of T12F-COOH in DMF is governed by the emission from a locally excited state (S1, ~ 0.4 ns), a charge-transfer state (S1(CT), ~ 2 ns), and a room temperature emissive triplet state (T1, ~ 20 ns), in addition to a non-emissive triplet structure with a charge-transfer character (T1(CT), τ = 0.75 µs). We also report on the results using T12F-ester. Interestingly, FLIM experiments on single crystals unravel that the emission lifetimes of the crystalline HOF are almost twice those of the amorphous ones or the solid T12F-ester sample. This shows the relevance of the H-bonds in the photodynamics of the HOF and provides a strong basis for further development and study of HOFs based on DBAs for potential applications in photonics.


2022 ◽  
Author(s):  
Hui Jiang ◽  
Jun Ye ◽  
Peng Hu ◽  
Shengli Zhu ◽  
Yanqin Liang ◽  
...  

Co-crystallization is an efficient way of molecular crystal engineering to tune the electronic properties of organic semiconductors. In this work, we synthesized anthracene-4,8-bis(dicyanomethylene)4,8-dihydrobenzo[1,2-b:4,5-b’]-dithiophene (DTTCNQ) single crystals as a template to...


1997 ◽  
Vol 106 (8) ◽  
pp. 3067-3077 ◽  
Author(s):  
M. Karbowiak ◽  
J. Drozdzynski ◽  
K. M. Murdoch ◽  
N. M. Edelstein ◽  
S. Hubert

1981 ◽  
Vol 103 (15) ◽  
pp. 4382-4388 ◽  
Author(s):  
K. W. Penfield ◽  
R. R. Gay ◽  
R. S. Himmelwright ◽  
N. C. Eickman ◽  
V. A. Norris ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document