Effect of solvent on the electronic absorption spectral properties of Ni(II) and Cu(II)-complexes of some mixed β-octasubstituted-meso-tetraphenylporphyrins

2019 ◽  
Vol 730 ◽  
pp. 643-648 ◽  
Author(s):  
Muniappan Sankar ◽  
Puttaiah Bhyrappa
2010 ◽  
Vol 14 (09) ◽  
pp. 793-803 ◽  
Author(s):  
Maria Pia Donzello ◽  
Elisa Viola ◽  
Larisa A. Tomachinskaya ◽  
Claudio Ercolani ◽  
Maddalena Corsini ◽  
...  

New styryl-substituted tetrapyrazinoporphyrazines [St8PyzPzM] (M = 2NaI , MgII(H2O) and ZnII ; St = -CH=CHAr , where Ar = phenyl or cumyl) were prepared by template cyclotetramerization of 5,6-distyrylpyrazine-2,3-dicarbonitriles available from condensation of diaminomaleodinitrile with the substituted cinnamils (StCO)2 obtained from biacetyl and arylaldehydes ArCHO . The new porphyrazine macrocycles were characterized by electronic absorption and emission spectra, which provide evidence of efficient π-interaction of the peripheral styryl moieties with the central pyrazinoporphyrazine framework. The electronic excitation of the stylbenoid chromophore in the near UV-region (400 nm) leads to strong emission of the porphyrazine chromophore near 700 nm, allowing to consider the styryl-substituted porphyrazines as efficient light-harvesting species. Their spectral properties and electrochemical behavior are compared with those of stylbenoid phthalocyanines and peripherally substituted tetrapyrazinoporphyrazines.


1989 ◽  
Vol 54 (5) ◽  
pp. 1203-1208 ◽  
Author(s):  
Jiří Krechl ◽  
Stanislav Böhm ◽  
Josef Kuthan

Electronic absorption spectra of coenzyme PQQ and its reduced form, PQQH2, were calculated by the CNDO/S-CI method. The use of 170 monoexcited configurations was found to be necessary in order to give the correct interpretation of observed UV absorption. Influence of the carboxylic group geometries on the spectra is discussed.


2019 ◽  
Vol 285 ◽  
pp. 194-203 ◽  
Author(s):  
Galina B. Guseva ◽  
Alexander A. Ksenofontov ◽  
Elena V. Antina ◽  
Mikhail B. Berezin ◽  
Anatoliy I. Vyugin

1983 ◽  
Vol 36 (7) ◽  
pp. 1361 ◽  
Author(s):  
H Becker ◽  
BW Skelton ◽  
AH White

The Diels-Alder addition of dimethyl acetylenedicarboxylate to sterically hindered 2,4-cyclohexadienones (spiro-quinol ethers) gives rise to stereoisomeric bicyclo[2.2.2]octadienones. The structures of three of these have been elucidated by single-crystal X-ray diffraction methods and their 1H n.m.r. and electronic absorption spectral properties are reported.


2019 ◽  
Vol 288 ◽  
pp. 111094
Author(s):  
Galina B. Guseva ◽  
Alexander A. Ksenofontov ◽  
Elena V. Antina ◽  
Mikhail B. Berezin ◽  
Anatoliy I. Vyugin

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