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.

Synthesis, field-effect and photovoltaic properties of random difluorobenzothiadiazole-isoindigo electron donor-acceptor polymers

2016 ◽  
Vol 134 ◽  
pp. 251-257 ◽  
Author(s):  
Ping Deng ◽  
Yanlian Lei ◽  
Bo Wu ◽  
Xuelin Zheng ◽  
Yong Lu ◽  
...  
Keyword(s):  
Electron Donor ◽  
Field Effect ◽  
Photovoltaic Properties ◽  
Donor Acceptor

scholarly journals Synthesis and photovoltaic properties of thieno[3,2-b]thiophenyl substituted benzo[1,2-b:4,5-b′]dithiophene copolymers

2014 ◽  
Vol 5 (23) ◽  
pp. 6710-6717 ◽  
Author(s):  
Zeyun Xiao ◽  
Jegadesan Subbiah ◽  
Kuan Sun ◽  
David J. Jones ◽  
Andrew B. Holmes ◽  
...  
Keyword(s):  
Solar Cell ◽  
Electron Donor ◽  
Building Block ◽  
Bulk Heterojunction ◽  
Heterojunction Solar Cell ◽  
Photovoltaic Properties ◽  
Bulk Heterojunction Solar Cell ◽  
Donor Acceptor

A new thienothiophene–benzodithiophene electron donor building block was synthesized and incorporated into 2-dimensional conjugated donor–acceptor polymers. The polymers were fully characterised and tested in bulk heterojunction solar cell devices.

Chiral Liquid Crystal Polymers Containing Electron Donor- Acceptor Action-Synthesis and Characterization

2011 ◽  
Vol 284-286 ◽  
pp. 2284-2287
Author(s):  
Xiao Zhi He ◽  
Mei Tian ◽  
Yang Chen ◽  
Jing Zhao ◽  
Bao Yan Zhang
Keyword(s):  
Electron Donor ◽  
Liquid Crystalline ◽  
Proton Nuclear Magnetic Resonance ◽  
Liquid Crystal Polymers ◽  
Scanning Calorimetry ◽  
Cholesteric Phase ◽  
Chemical Structures ◽  
Heating And Cooling ◽  
Acceptor Group ◽  
Donor Acceptor

A series of new chiral side-chain liquid crystalline polymers with electron donor-acceptor action were prepared containing chiral monomer with donor group and nematic LC monomer with acceptor group. All polymers were synthesized by graft polymerization using polymethylhydro- siloxane as backbone. The mesomorphic properties were investigated by differential scanning calorimetry(DSC), polarizing optical microscopy(POM)，thermogravimetric analyses（TGA） and X-ray diffraction measurements(XRD). The chemical structures of monomers and polymers were confirmed by Fourier transform infrared (FTIR), proton nuclear magnetic resonance spectra(1H NMR and 13CNMR). M1 showed nematic phase and M2 turned out cholesteric phase on heating and cooling cycle. Polymers P3~P8 were cholesteric phase. Experimental results demonstrated that the glass transition temperatures and isotropization temperatures and the ranges of the mesophase temperature increased with increasing the content of chiral agent. All of the obtained polymers showed high thermal stability.

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.

Two Excited State Structures of Donor-Acceptor Substituted "Proton Sponge"

2005 ◽  
Vol 277-279 ◽  
pp. 1060-0 ◽  
Author(s):  
A. Szemik Hojniak ◽  
I. Deperasińska ◽  
W.J. Buma ◽  
G. Balkowski ◽  
A.F. Pozharsky ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Ground State ◽  
Experimental Spectrum ◽  
Proton Sponge ◽  
Strong Electron ◽  
Acceptor Group ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Ab Initio Hf

Photoexcitation of “proton sponge” 1,8-bis (dimethylamino) naphthalene (DMAN) leads to charge transfer (CT) emission. This work demonstrates that substitution of DMAN with a strong electron acceptor group (CN) results in CN-DMAN and leads to a stronger orbital decoupling between the Donor and Acceptor groups and to a more effective CT process (λF = 630 nm). The theoretical absorption spectrum calculated for CN-DMAN using the ZINDO method on its ground state ab initio [HF/6-31G(d)] optimized geometry reproduces a better experimental spectrum than that calculated using the RCIS method. It also shows that AM1 excited state (1La) optimization reveals two quasi-degenerated states with anti-quinoidal (A) and quinoidal (B) structures and the CT nature. Both structures may contribute more or less equally to the fluorescence of CN-DMAN in a solution.

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-

Indeno[1,2-b]fluorene-based novel donor–acceptor conjugated copolymers

2017 ◽  
Vol 30 (2) ◽  
pp. 192-201 ◽  
Author(s):  
Ying Sun ◽  
Xiaojing Ding ◽  
Xueqin Zhang ◽  
Qizan Huang ◽  
Baoping Lin ◽  
...  
Keyword(s):  
Photovoltaic Performance ◽  
Hole Mobility ◽  
Molecular Geometry ◽  
Strong Electron ◽  
Photovoltaic Properties ◽  
Polymer Backbone ◽  
Photovoltaic Efficiency ◽  
Donor Acceptor ◽  
Electron Deficiency ◽  
Conjugated Copolymers

A series of conjugated copolymers based on indeno[1,2-b]fluorene as donor unit with different acceptor units have been synthesized to explore the influences of molecular backbone planarization and acceptor electronegativity on charge transport and photovoltaic properties. Polymer incorporating 2,3-diphenylquinoxaline acceptor moiety shows poor light-harvesting capacity and inferior photovoltaic efficiency of 0.5% due to twisted geometry. By introducing the stronger acceptor thiadiazolo[3,4-c]pyridine in polymer, intramolecular charge transfer is enhanced, giving rise to improved absorption property and photovoltaic efficiency of 1.39%. However, the polymer backbone is still twisted. When thiophene-flanked diketopyrrolopyrrole (DPP) is incorporated as electron acceptor, the polymer exhibits a more planar molecular geometry, yielding a broader and red-shifted absorption spectrum as well as a significantly improved hole mobility of 1.46E-2 cm2 V−1 s−1. However, the photovoltaic device efficiency is only enhanced to be 1.69%. The low-lying lowest unoccupied molecular orbital of −3.95 eV as a result of the strong electron deficiency of the DPP unit may lead to the inefficient charge dissociation and increase the charge recombination, which may give rise to the limit photovoltaic performance.

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