Structural and theoretical analysis of some mesogenic azines containing strong electron donor–acceptor groups

1997 ◽  
pp. 79-84 ◽  
Author(s):  
Roberto Centore ◽  
Carmine Garzillo
Keyword(s):  
Theoretical Analysis ◽  
Electron Donor ◽  
Strong Electron ◽  
Donor Acceptor

Quantum chemical study of physical characteristics of Co- and Ni-faujasites

1982 ◽  
Vol 47 (5) ◽  
pp. 1282-1289 ◽  
Author(s):  
Stanislav Beran
Keyword(s):  
Electron Donor ◽  
Quantum Chemical Study ◽  
Chemical Characterization ◽  
Chemical Study ◽  
Hydroxyl Groups ◽  
Strong Electron ◽  
Charge Densities ◽  
Physico Chemical ◽  
Donor Acceptor ◽  
Trivalent Cations

The CNDO/2 method was used for a physico-chemical characterization of faujasite zeolites, modelled by T6O6(OH)12 clusters containing Ni+, Ni2+, Ni(OH)+, Co2+, Co3+, Co(OH)+ cations localized in the SII and SI' cationic positions. It is shown that the cations are bound preferentially to the oxygen atoms of the zeolite skeleton by a strong electron donor-acceptor bond. As the consequence of the bond formation, the electron charge is significantly shifted from a skeleton to the cation. The charge densities calculated on the cations (Ni+ ~ 0.3, Ni2+ ~ 0.35, Co2+ ~ 0.4, Co3+ ~ 1.1 respectively) show that with uni- and bivalent cations the positive charge is in main part compensated by donation of electrons from the skeleton, while with trivalent cations the compensation is only partial. The Ni+ cation possesses significant electron donor properties whereas the Co3+ cation has a strong electron acceptor character. For both cations bivalency appears to be the most stable valent state. Both studied cations show great affinity to hydratation, however, their corresponding hydroxyl adducts - the Ni(OH)+ and Co(OH)+ cations exhibit substantially less acid properties, compared with the hydroxyl groups of the skeleton.

Structural analysis of some benzoxazoles containing strong electron donor-acceptor groups

1997 ◽  
Vol 212 (12) ◽  
Author(s):  
R. Centore ◽  
A. Tuzi ◽  
B. Panunzi
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Structure Analysis ◽  
Electron Donor ◽  
Crystal Structure Analysis ◽  
Strong Electron ◽  
Donor Acceptor

AbstractThe crystal structure analysis of two benzoxazole containing molecules is reported: 2-[4-

scholarly journals Push-Pull Heterocyclic Dyes Based on Pyrrole and Thiophene: Synthesis and Evaluation of Their Optical, Redox and Photovoltaic Properties

Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 34
Author(s):  
Sara S. M. Fernandes ◽  
Maria Cidália R. Castro ◽  
Dzmitry Ivanou ◽  
Adélio Mendes ◽  
Maria Manuela M. Raposo
Keyword(s):  
Electron Donor ◽  
Oxidation Potential ◽  
Cyanoacetic Acid ◽  
Strong Electron ◽  
Photovoltaic Properties ◽  
Heterocyclic Molecules ◽  
Acceptor Group ◽  
Donor Acceptor ◽  
Ethoxyl Group ◽  
Anchoring Groups

Three heterocyclic dyes were synthesized having in mind the changes in the photovoltaic, optical and redox properties by functionalization of 5-aryl-thieno[3,2-b]thiophene, 5-arylthiophene and bis-methylpyrrolylthiophene π-bridges with different donor, acceptor/anchoring groups. Knoevenagel condensation of the aldehyde precursors with 2-cyanoacetic acid was used to prepare the donor-acceptor functionalized heterocyclic molecules. These organic metal-free dyes are constituted by thieno[3,2-b]thiophene, arylthiophene, bis-methylpyrrolylthiophene, spacers and one or two cyanoacetic acid acceptor groups and different electron donor groups (alkoxyl, and pyrrole electron-rich heterocycle). The evaluation of the redox, optical and photovoltaic properties of these compounds indicate that 5-aryl-thieno[3,2-b]thiophene-based dye functionalized with an ethoxyl electron donor and a cyanoacetic acid electron acceptor group/anchoring moiety displays as sensitizer for DSSCs the best conversion efficiency (2.21%). It is mainly assigned to the higher molar extinction coefficient, long π-conjugation of the heterocyclic system, higher oxidation potential and strong electron donating capacity of the ethoxyl group compared to the pirrolyl moiety.

Metal-Free Photoinduced Hydroalkylation Cascade Enabled by an Electron-Donor-Acceptor Complex

2020 ◽  
Author(s):  
José Tiago Menezes Correia ◽  
Gustavo Piva da Silva ◽  
Camila Menezes Kisukuri ◽  
Elias André ◽  
Bruno Pires ◽  
...  
Keyword(s):  
Electron Donor ◽  
Functional Group ◽  
Photoexcited Electron ◽  
One Pot ◽  
Quaternary Centers ◽  
Metal Free ◽  
Acceptor Complex ◽  
Catalyst Free ◽  
Donor Acceptor ◽  
Radical Cascade

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.

Capturing polycyclic aromatic sulfur heterocycles in electron donor–acceptor complexes

2021 ◽  
Vol 31 (3) ◽  
pp. 326-329
Author(s):  
Olga E. Eremina ◽  
Mariia V. Samodelova ◽  
Mariia V. Ferree ◽  
Tatyana N. Shekhovtsova ◽  
Irina A. Veselova
Keyword(s):  
Electron Donor ◽  
Polycyclic Aromatic Sulfur Heterocycles ◽  
Polycyclic Aromatic ◽  
Donor Acceptor ◽  
Sulfur Heterocycles
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