The influence of solvent polarity on the tetrahedral-octahedral equilibrium of Co(II)complexes with 3,5-dimethylpyrazole

Polyhedron ◽  
1984 ◽  
Vol 3 (2) ◽  
pp. 251-255 ◽  
Author(s):  
A. Anagnostopoulos ◽  
S. Hadjispyrou
1990 ◽  
Vol 55 (8) ◽  
pp. 1891-1895 ◽  
Author(s):  
Peter Ertl

Twisting of the NMe2 group in p-N,N-dimethylaminobenzonitrile (DMABN) was investigated using AM1 semiempirical method with configuration interaction. Effect of polar media was considered by placing + and - charge centers ("sparkles") at appropriate places opposite the molecule. Optimized ground state geometry of DMABN is slightly twisted with the lowest vertical excited state of 1B character. As the polarity of media increases and/or the - NMe2 group twists, the symmetric 1A excited state having considerable charge separation becomes energetically favorable. Anomalous long-wavelength emission of DMABN comes from this state.


2021 ◽  
Vol 14 (2) ◽  
pp. 138
Author(s):  
Bauyrzhan Myrzakhmetov ◽  
Philippe Arnoux ◽  
Serge Mordon ◽  
Samir Acherar ◽  
Irina Tsoy ◽  
...  

Photodynamic therapy (PDT) is an innovative treatment of malignant or diseased tissues. The effectiveness of PDT depends on light dosimetry, oxygen availability, and properties of the photosensitizer (PS). Depending on the medium, photophysical properties of the PS can change leading to increase or decrease in fluorescence emission and formation of reactive oxygen species (ROS) especially singlet oxygen (1O2). In this study, the influence of solvent polarity, viscosity, concentration, temperature, and pH medium on the photophysical properties of protoporphyrin IX, pyropheophorbide-a, and Photofrin® were investigated by UV-visible absorption, fluorescence emission, singlet oxygen emission, and time-resolved fluorescence spectroscopies.


Optica ◽  
2015 ◽  
Vol 2 (5) ◽  
pp. 447 ◽  
Author(s):  
J. L. Dominguez-Juarez ◽  
S. Vallone ◽  
A. Lempel ◽  
M. Moocarme ◽  
J. Oh ◽  
...  

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