Alternating Donor/Acceptor Repeat Units in Polythiophenes. Intramolecular Charge Transfer for Reducing Band Gaps in Fully Substituted Conjugated Polymers

1998 ◽  
Vol 120 (22) ◽  
pp. 5355-5362 ◽  
Author(s):  
Qing T. Zhang ◽  
James M. Tour
Keyword(s):  
Charge Transfer ◽  
Conjugated Polymers ◽  
Intramolecular Charge Transfer ◽  
Band Gaps ◽  
Repeat Units ◽  
Donor Acceptor

Novel low-band-gap conjugated polymers using an alternating donor/acceptor repeat unit

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Phimwipha Piyakulawat ◽  
Anusit Keawprajak ◽  
Anon Chindaduang ◽  
Anke Helfer ◽  
Udom Asawapirom
Keyword(s):  
Cyclic Voltammetry ◽  
Charge Transfer ◽  
Conjugated Polymers ◽  
Lower Energy ◽  
Intramolecular Charge Transfer ◽  
Repeat Unit ◽  
Band Gaps ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Positive Step

AbstractA series of new π-conjugated donor-acceptor copolymers, based on a naphthalene-bisimide moiety as the electron-acceptor and connected to either thiophene or dialkylfluorene as the electron-donor, were synthesized. The polymers are soluble in common organic solvents. The UV-Vis spectra of the copolymers in chloroform showed two absorption maxima at higher energies (ca. 301 - 364 nm), assigned to the π-π * transition, and at a lower energy (ca. 512 - 595 nm), ascribed to the intramolecular charge transfer between donor and acceptor units. Cyclic voltammetry revealed that the polymers were susceptible to both electrochemical oxidation and reduction, and they had a LUMO and HOMO levels ranging from -4.07 to -3.80 eV and -6.13 to -5.64 eV, respectively. The energy band gaps were estimated to be 1.48 - 2.06 eV. These results represent a positive step towards making novel compounds suitable for electronic applications.

scholarly journals Conjugated Polymer Donor-Molecular Acceptor Nanohybrids for Photocatalytic Hydrogen Evolution

2019 ◽  
Author(s):  
Haofan Yang ◽  
Xiaobo Li ◽  
Reiner Sebastian Sprick ◽  
Andrew I. Cooper
Keyword(s):  
Photocatalytic Activity ◽  
Charge Transfer ◽  
Conjugated Polymers ◽  
Hydrogen Evolution ◽  
Conjugated Polymer ◽  
Apparent Quantum Yield ◽  
High Hydrogen ◽  
Photocatalytic Hydrogen Evolution ◽  
Efficient Charge ◽  
Donor Acceptor

A library of 237 organic binary/ternary nanohybrids consisting of conjugated polymers donors and both fullerene and non-fullerene molecular acceptors was prepared and screened for sacrificial photocatalytic hydrogen evolution. These donor-acceptor nanohybrids (DANHs) showed significantly enhanced hydrogen evolution rates compared with the parent donor or acceptor compounds. DANHs of <a></a><a>a polycarbazole</a>-based donor combined with a methanofullerene acceptor (PCDTBT/PC<sub>60</sub>BM) showed a high hydrogen evolution rate of 105.2 mmol g<sup>-1</sup> h<sup>-1</sup> under visible light (λ > 420 nm). This DANH photocatalyst produced 5.9 times more hydrogen than a sulfone-containing polymer (P10) under the same conditions, which is one of the most efficient organic photocatalysts reported so far. An apparent quantum yield of hydrogen evolution of 3.0 % at 595 nm was measured for this DANH. The photocatalytic activity of the DANHs, which in optimized cases reached 179.0 mmol g<sup>-1</sup> h<sup>-1</sup>, is attributed to efficient charge transfer at the polymer donor/molecular acceptor interface. We also show that ternary donor<sub>A</sub>-donor<sub>B</sub>-acceptor nanohybrids can give higher activities than binary donor-acceptor hybrids in some cases.

scholarly journals Tuning of Hyperpolarizability, One- and Two-Photon Absorption of D-A and D-A-A Type Intramolecular Charge Transfer Based Sensors

2019 ◽  
Author(s):  
Pralok K. Samanta ◽  
Md Mehboob Alam ◽  
Ramprasad Misra ◽  
Swapan K. Pati
Keyword(s):  
Charge Transfer ◽  
Gas Phase ◽  
Density Functional ◽  
Intramolecular Charge Transfer ◽  
Photon Absorption ◽  
First Hyperpolarizability ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Nlo Response ◽  
Donor Acceptor

Solvents play an important role in shaping the intramolecular charge transfer (ICT) properties of π-conjugated molecules, which in turn can affect their one-photon absorption (OPA) and two-photon absorption (TPA) as well as the static (hyper)polarizabilities. Here, we study the effect of solvent and donor-acceptor arrangement on linear and nonlinear optical (NLO) response properties of two novel ICT-based fluorescent sensors, one consisting of hemicyanine and dimethylaniline as electron withdrawing and donating groups (molecule 1), respectively and its boron-dipyrromethene (BODIPY, molecule 2)-fused counterpart (molecule 3). Density functional theoretical (DFT) calculations using long-range corrected CAM-B3LYP and M06-2X functionals, suitable for studying properties of ICT molecules, are employed to calculate the desired properties. The dipole moment (µ) as well as the total first hyperpolarizability (β<sub>total</sub>) of the studied molecules in the gas phase is dominantly dictated by the component in the direction of charge transfer. The ratios of vector component of first hyperpolarizability (β<sub>vec</sub>) to β<sub>total</sub> also reveal unidirectional charge transfer process. The properties of the medium significantly affect the OPA, hyperpolarizability and TPA properties of the studied molecules. Time dependent DFT (TDDFT) calculations suggest interchanging between two lowest excited states of molecule 3 from the gas phase to salvation. The direction of charge polarization and dominant transitions among molecular orbitals involved in the OPA and TPA processes are studied. The results presented are expected to be useful in tuning the NLO response of many ICT-based chromophores, especially those with BODIPY acceptors.<br>

scholarly journals N-Substitution of acridone with electron-donating groups: crystal packing, intramolecular charge transfer and tuneable aggregation induced emission

RSC Advances ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 7092-7098 ◽  
Author(s):  
Renfei Liu ◽  
Guanxing Zhu ◽  
Gang Zhang
Keyword(s):  
Charge Transfer ◽  
Transfer Process ◽  
Intramolecular Charge Transfer ◽  
Crystal Packing ◽  
Charge Transfer Process ◽  
Aggregation Induced Emission ◽  
Donor Acceptor ◽  
Electron Donating Groups

Triphenylamine functionalized acridone leads to a donor–acceptor system with intramolecular charge transfer process and tuneable aggregation induced enhanced emission.

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