Synthesis of a new W-type of functional polymer for improving intermolecular charge transfer processes at donor/acceptor interfaces

2019 ◽  
Vol 31 (5) ◽  
pp. 521-527 ◽  
Author(s):  
Yun-Fan Zhang ◽  
Fawen Wu
Keyword(s):  
Charge Transfer ◽  
Energy Gap ◽  
Energy Levels ◽  
Coupling Reaction ◽  
Photocurrent Density ◽  
Orbital Energy ◽  
Functional Polymer ◽  
Suzuki Coupling Reaction ◽  
Donor Acceptor ◽  
Lowest Unoccupied Molecular Orbital

Optimizing charge transfer (CT) processes at donor/acceptor interfaces is an important subject to improving photocurrent density. Geometries of functional polymers play important roles in design of new types of polymers, which were used as electron donor to improve effective separation of electron-hole pairs at donor/acceptor interfaces. In this article, a novel W-type of polymer, poly(1-[4-(9-(2-ethylhexyl)carbazole-3-yl)]phenylazo-2-phenylazoacenaphthylene), was synthesized by a Suzuki coupling reaction for improving interaction between polymers and electron acceptors to enhance intermolecular CT. Geometry of combination of the polymer and C60 shows that main-chain of the polymer could sufficiently touch C60 derivatives. The polymer exhibited a broadband light absorption at the wavelength range from 250 to 650 nm. Ultraviolet–visible spectra and cyclic voltammetry curve suggest that the highest occupied, lowest unoccupied molecular orbital energy levels, and energy gap values are −5.09, −3.18 and 1.91 eV. Fluorescence quenching experiments shows that 99.9% of emission fluorescence of the polymer was quenched by added C60. Therefore, excited electrons at the polymer would be completely transferred to C60 molecules. This article suggests a new W-type functional polymer for improving intermolecular CT processes at donor/acceptor interfaces.

scholarly journals Synthesis and Characterization of Metallo-Supramolecular Polymers Based on Benzodipyrrolidone

2021 ◽  
Vol 9 ◽  
Author(s):  
Zheng Chi ◽  
Hao Dong ◽  
Ganhui Shi ◽  
Pan Liu ◽  
Chenchen Ma ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Self Assembly ◽  
Energy Gap ◽  
Coupling Reaction ◽  
Building Blocks ◽  
Supramolecular Polymers ◽  
Absorption Bands ◽  
Suzuki Coupling Reaction ◽  
Ligand Charge Transfer ◽  
Common Precursor

A simple route to the preparation of benzodipyrrolidone (BDP) based monomeric building blocks containing 2,2′:6′,2″-terpyridines is reported from a common precursor 4′-(4-pinacolatoboronphenyl)-2,2′:6′,2″-terpyridine via Suzuki coupling reaction. Self-assembly polymerization with ruthenium (II) ions under mild conditions yielded a series of novel metallo-supramolecular polymers with weak donor-acceptor (D-A) structures based on benzodipyrrolidone. The structure of the bridge connected BDP with terpyridine have a significant impact on the wavelength and intensity of the intramolecular charge transfer (ICT) absorption peak. The resulting metallo-polymers exhibited strong double absorption bands around 315 nm and 510 nm involved in π-π* transitions and ICT or metal to ligand charge transfer (MLCT) absorption bands. The forming of D-A structure and coordination with ruthenium (II) ions is favorable to narrow the energy gap and the energy gaps of the resulting metallo-supramolecular polymers are 2.01 and 1.62 eV, respectively.

scholarly journals Synthesis and Characterization of Fluorene-Based Polymers Having Azine Unit for Blue Light Emission

2015 ◽  
Vol 62 ◽  
pp. 21-28
Author(s):  
Zhong Min Geng ◽  
Masashi Kijima
Keyword(s):  
Molecular Orbital ◽  
Light Emission ◽  
Energy Levels ◽  
Average Molecular Weight ◽  
Orbital Energy ◽  
Good Thermal Stability ◽  
Highest Occupied Molecular Orbital ◽  
Donor Acceptor ◽  
Lowest Unoccupied Molecular Orbital

Two types of donor-acceptor copolymers were designed and synthesized by combination of an electron donor unit of fluorene sequences and an electron acceptor azine unit such as 1,2,4,5-tetrazine and 1,3,5-triazine. They were well soluble in common organic solvents with the number average molecular weight (Mn) of 7.0 and 14.5 kg mol-1, respectively, and have good thermal stability showing about at 360 °C with 5 wt% loss in TGA. Two copolymers exhibited intense blue photoluminescence with emission peak maxima at 437 and 421 nm in CHCl3, and 451 and 422 nm in the film state, respectively. These polymers exhibited good fluorescence quantum efficiencies in CHCl3 (φfl = 0.63, 0.97). Energy levels of the highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels estimated by cyclic voltammetry were to be –5.83, –6.0 eV and –2.85, –2.88 eV, respectively.

scholarly journals Effect of the second chromophore energy gap on photo-induced electron injection in di-chromophoric porphyrin-sensitized solar cells

2018 ◽  
Vol 5 (9) ◽  
pp. 181218 ◽  
Author(s):  
Long Zhao
Keyword(s):  
Solar Cells ◽  
Energy Gap ◽  
Dye Sensitized Solar Cells ◽  
Orbital Energy ◽  
Charge Generation ◽  
Organic Chromophores ◽  
Main Charge ◽  
Lowest Unoccupied Molecular Orbital ◽  
Organic Chromophore ◽  
Sensitized Solar Cells

This work investigates the effect of the second chromophore energy gap on charge generation in porphyrin-based di-chromophoric dye-sensitized solar cells (DSSCs). Three di-chromophoric porphyrin dyes (PorY, PorO and PorR) containing three organic chromophores with decreasing frontier orbital energy offsets, including a carbazole-triphenylamine chromophore (yellow, Y), a carbazole fused-thiophene chromophore (orange, O) or a carbazole-thiophene benzothiadiazole thiophene chromophore (red, R), were investigated using optical and electrochemical methods, steady-state photoluminescence and photovoltaic device characterization. Energy transfer from the organic chromophore to the porphyrin was suggested in PorY and PorO as the main charge generation mechanism in DSSCs using these di-chromophoric dyes. On the other hand, electron transfer from the photo-excited porphyrin to the organic chromophore as a competing pathway leading to the loss of photocurrent is suggested for PorR-sensitized solar cells. The latter pathway leading to a loss of photocurrent is due to the lower lying lowest unoccupied molecular orbital of the additional organic chromophore (R) and suggests the limitation of the current di-chromophoric approach to increase the overall efficiency of DSSCs.

Thiazole as a weak electron-donor unit to lower the frontier orbital energy levels of donor–acceptor alternating conjugated materials

2013 ◽  
Vol 49 (85) ◽  
pp. 9938 ◽  
Author(s):  
Elena Zaborova ◽  
Patricia Chávez ◽  
Rony Bechara ◽  
Patrick Lévêque ◽  
Thomas Heiser ◽  
...  
Keyword(s):  
Electron Donor ◽  
Energy Levels ◽  
Orbital Energy ◽  
Frontier Orbital ◽  
Conjugated Materials ◽  
Donor Acceptor ◽  
Weak Electron ◽  
Frontier Orbital Energy

scholarly journals Theoretical study on electronic and absorption characters of p-type D-A-π-A triaryamine sensitizer

2018 ◽  
Vol 96 (4) ◽  
pp. 425-429 ◽  
Author(s):  
Wen Yan ◽  
Zhi-Dan Sun ◽  
Xue-Hai Ju
Keyword(s):  
Energy Gap ◽  
Energy Levels ◽  
Hole Injection ◽  
Orbital Energy ◽  
Computational Techniques ◽  
Absorption Properties ◽  
Type D ◽  
Structural And Electronic Properties ◽  
Dye Regeneration ◽  
P Type

The structural and electronic properties of well-known 4,4′-(4-(5-(2,2-dicyanovinyl)thiophen-2-yl)phenylazanediyl)dibenzoic acid (O2) and its hypothetical dyes O3–O7 were investigated by computational techniques. The absorption properties were probed. By replacing the 2-methylidenepropanedinitrile acceptor with 1,3-diethyl-5-methylene-2-thioxo-dihydropyrimidine-4,6(1H,5H)-dione, the molecular orbital energy levels were well tuned. The modified dyes meet the basic requirements of both –ΔGinj and –ΔGreg being over 0.2 eV for an efficient hole injection and dye regeneration, respectively. All the designed p-type dyes O3–O7 have smaller energy gap and significant red shift in absorption spectra than that of the reference O2. Finally, our results suggested that O3–O7 have larger light-harvesting efficiencies (LHE) in the visible spectral regions of 400 nm to 700 nm than O2. Among all the dyes, O5 is expected to have an excellent performance as a p-type sensitized dye in solar cells due to its great LHE and sufficient hole injection efficiency.

scholarly journals Synthesis and application of a new class of D–π–A type charge transfer probe containing imidazole – naphthalene units for detection of F− and CO2

RSC Advances ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. 4941-4949 ◽  
Author(s):  
Ramesh C. Gupta ◽  
Rashid Ali ◽  
Syed S. Razi ◽  
Priyanka Srivastava ◽  
Sushil K. Dwivedi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Coupling Reaction ◽  
Suzuki Coupling ◽  
Suzuki Coupling Reaction ◽  
New Class ◽  
Donor And Acceptor

A new class of D–π–A type charge transfer probe, 3 and 4, containing imidazole – naphthalene moieties as donor and acceptor, respectively, has been synthesized via a Suzuki coupling reaction.

scholarly journals Multiple Charge Transfer States in Donor–Acceptor Heterojunctions with Large Frontier Orbital Energy Offsets

2019 ◽  
Vol 31 (17) ◽  
pp. 6808-6817 ◽  
Author(s):  
Saeed-Uz-Zaman Khan ◽  
Giacomo Londi ◽  
Xiao Liu ◽  
Michael A. Fusella ◽  
Gabriele D’Avino ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Orbital Energy ◽  
Frontier Orbital ◽  
Donor Acceptor ◽  
Multiple Charge ◽  
Frontier Orbital Energy

EXCITED-STATE INTRAMOLECULAR ELECTRON TRANSFER COUPLED WITH EXCITED-STATE INTRAMOLECULAR PROTON TRANSFER IN PHOTOINDUCED ENOL TO KETO TAUTOMERIZATION

2009 ◽  
Vol 08 (supp01) ◽  
pp. 1073-1086
Author(s):  
YUANZUO LI ◽  
SHASHA LIU ◽  
LILI ZHAO ◽  
MAODU CHEN ◽  
FENGCAI MA ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Transfer ◽  
Proton Transfer ◽  
Molecular Orbital ◽  
Energy Levels ◽  
Three Dimensional ◽  
Intramolecular Proton Transfer ◽  
Intramolecular Electron Transfer ◽  
Lowest Unoccupied Molecular Orbital

In this paper, the two-dimensional (2D) site and the three-dimensional (3D) cube representations [Sun MT, J Chem Phys124: 054903, 2006] have been further developed to study the charge transfer during excited-state relaxation. With these newly developed representations, we theoretically investigate the excited-state intramolecular electron transfer (ESIET) in enol excited-state geometry relaxation, and ESIET coupled with excited-state intramolecular proton transfer (ESIPT) in phototautomerization (in enol to keto transformation). The energy levels of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of HBODC in enol and keto absorption and fluorescence are compared to understand photoinduced ESIET and ESIPT process. The excited regions of molecule (where arrangement of electron density takes place during excited-state relaxation) are located with 2D site representation. 3D cube representations visualize the character of charge transfer (CT) in those regions. Results of the research indicate that the ability of charge transfer during enol excited-state geometry relaxation is much stronger than that in phototautomerization.

CONTROL OF SUCCESSIVELY SWITCHING FROM LLCT TO ILCT AND MLCT EXCITED STATES IN PLATINUM(II) TERPYRIDYL ACETYLIDE COMPLEXES BY SEQUENTIAL PROTONATIONS

2008 ◽  
Vol 07 (01) ◽  
pp. 103-111 ◽  
Author(s):  
SHASHA LIU ◽  
YONG DING ◽  
XIANGSI WANG ◽  
MAODU CHEN ◽  
ZHENJUN FAN
Keyword(s):  
Charge Transfer ◽  
Molecular Orbital ◽  
Excited States ◽  
Physical Mechanism ◽  
Energy Levels ◽  
Low Energy ◽  
Orbital Energy ◽  
Amino Group ◽  
Ligand Charge Transfer ◽  
Theoretical Evidence

Visualized theoretical evidence for successively switching from ligand-to-ligand charge transfer (LLCT) to intraligand charge transfer (ILCT) and then to metal-to-ligand charge transfer (MLCT) excited states in platinum(II) terpyridyl acetylide (PTA) complexes in low-energy absorption by sequential protonations has been given with charge transfer density, based on recently experimental report (Han X. et al., Chem Eur J13:1231, 2007). The sequential protonations have shown significant influence on the molecular geometries, ionization potential, affinity potential, and band gap of PTA. The protonations on the amino group of the ligands result in the shift of the molecular orbital energy levels of PTA. The physical mechanism of switching from LLCT to ILCT and then to MLCT excited states by sequential protonations is interpreted with the theory of molecular orbital transitions.

scholarly journals Synthesis, Geometry Structure and Properties of N, N’-Carbonic Bis(Piperonylic Acid) Dihydrazide

2020 ◽  
Vol 213 ◽  
pp. 01014
Author(s):  
Yanhua Cai ◽  
Lian Luo ◽  
Jun Qiao ◽  
Lisha Zhao
Keyword(s):  
Molecular Orbital ◽  
Energy Gap ◽  
Geometry Optimization ◽  
Nucleation Site ◽  
Orbital Energy ◽  
Melt Crystallization ◽  
Heating Rates ◽  
Neat Plla ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

In this study, N, N’-carbonic bis(piperonylic acid) dihydrazide (BPACH) was synthesized to broaden the category of piperonylic acid derivative and evaluate its influences on the thermal properties of poly(L-lactic acid) (PLLA). The geometry optimization of BPACH showed that the highest occupied molecular orbital mainly focused on the formed amide group and carbonic dihydrazide, whereas the lowest unoccupied molecular orbital mainly focused on the piperonylic acid, and the orbital energy gap was 0.10418 eV. The differences in melt-crystallization processes of the neat PLLA and PLLA/BPACH samples indicated that the BPACH could provide the effective nucleation site to accelerate the crystallization of PLLA, but the crystallization accelerating effect was still further improved compared to some reported nucleating agents. The melting behaviors of PLLA/BPACH samples after crystallization depended on the crystallization temperatures and heating rates; additionally, the melting processes could also effectively reflect the previous crystallization behaviors.

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