3-Alkoxy-4-cyanothiophene units are used as building block for the synthesis of conjugated donor-acceptor-donor (D-A-D) triads. The donor part consists of benzothienothiophene end groups associated with the alkoxy groups of the 3-alkoxy-4-cyanothiophene, while the central acceptor part is formed by combining the electron-withdrawing cyano group with thiophene or benzothiadiazole units.
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http://dx.doi.org/10.1021/jo202412t | DOI Listing |
J Chem Phys
October 2024
Volgograd State University, University Avenue 100, Volgograd 400062, Russia.
In excited centrosymmetric donor-acceptor triads of type A-D-A or D-A-D, symmetry breaking charge transfer (SBCT) in polar media has been explored for a few decades. SBCT is accompanied by significant reorganization of the electronic structure of the molecule, which leads to a change in the fluorescence transition dipole moment (TDM). Previously, experiments revealed a 20%-30% reduction in TDM, which occurs on the timescale of SBCT.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2024
School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou, 213164, P. R. China.
Currently, much research effort has been devoted to improving the exciton utilization efficiency and narrowing the emission spectra of ultraviolet (UV) fluorophores for organic light-emitting diode (OLED) applications, while almost no attention has been paid to optimizing their light out-coupling efficiency. Here, we developed a linear donor-acceptor-donor (D-A-D) triad, namely CDFDB, which possesses high-lying reverse intersystem crossing (hRISC) property. Thanks to its integrated narrowband UV photoluminescence (PL) (λ: 397 nm; FWHM: 48 nm), moderate PL quantum yield (ϕ: 72 %, Tol), good triplet hot exciton (HE) conversion capability, and large horizontal dipole ratio (Θ: 92 %), the OLEDs based on CDFDB not only can emit UV electroluminescence with relatively good color purity (λ: 398 nm; CIE: 0.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2024
Department of Chemistry, Clemson University, 211 S. Palmetto Blvd., Clemson, South Carolina 29634, United States.
Charge-transfer (CT) interactions between co-facially aligned π-donor/acceptor (π-D/A) arrays engender unique optical and electronic properties that could benefit (supra)molecular electronics and energy technologies. Herein, we demonstrate that a tetragonal prismatic metal-organic cage (MOC1) having two parallel π-donor tetrakis(4-carboxyphenyl)-Zn-porphyrin (ZnTCPP) faces selectively intercalate planar π-acceptor guests, such as hexaazatriphenylene hexacarbonitrile (HATHCN), hexacyanotriphenylene (HCTP), and napthanelediimide (NDI) derivatives, forming 1:1 πA@MOC1 inclusion complexes featuring supramolecular π-D/A/D triads. The π-acidity of intercalated π-acceptors (HATHCN ≫ HCTP ≈ NDIs) dictated the nature and strength of their interactions with the ZnTCPP faces, which in turn influenced the binding affinities () and optical and electronic properties of corresponding πA@MOC1 inclusion complexes.
View Article and Find Full Text PDFJ Phys Chem A
April 2023
Department of Chemistry, National Institute of Technology, Tiruchirappalli, Tamil Nadu 620015, India.
Structure-property relationships of different conformers of an organic D-A-D triad are explored to rationalize the structural motif toward photoluminescence activity. In a recent experiment ( . .
View Article and Find Full Text PDFMater Horiz
October 2022
Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, People's Republic of China.
Here, we carried out a dipole moment engineering to convert a classical BN-PAH framework into a formal acceptor for the construction of bipolar OLED host materials, with this engineering involving the introduction of two "donor wings". The installation of the donors transformed the small local dipole moment of the BN-PAH framework into a large charge-transfer dipole moment, leading to a more separated frontier molecular orbital distribution beneficial for bipolar transport as well as a higher glass-transition temperature beneficial for morphological stability. The assembled donor-acceptor-donor (D-A-D) triads exhibited promising potential as universal bipolar hosts for the fabrication of OLEDs of various categories with wide color gamuts, such as blue multiple-resonance OLEDs (MR-OLEDs), green thermally activated delayed-fluorescence OLEDs (TADF-OLEDs), yellow TADF-sensitized fluorescence OLEDs (TSF-OLEDs), and red phosphorescence OLEDs (Ph-OLEDs).
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