Fengkun Chen

• PhD
• Faculty Member at Donghua University

Herein we report the first synthesis of a tetrabenzotetrathia[8]circulene by a “fold-in” type oxidative fusion reaction. Compared to the pristine tetrathia[8]circulene, the four-fold benzoannulation slightly weakened the antiaromatic character of...

Personalized wound dressings with on-site deposition, exudate suction, and reproducible sterilization are urged for treating diabetic wounds. Herein, we have developed nanofiber membranes incorporating a V-shaped photosensitizer (VPS), a donor-acceptor-donor type organic semiconductor with indacenodithienothiophene (IDTT) as the electron-donor and...

Utilizing water molecules to regulate the luminescence properties of solid materials is highly challenging. Herein, we develop a strategy to produce water‐triggered luminescence‐switching cocrystals by coassembling hydrophilic donors with electron‐deficient acceptors, where 1,2,4,5‐Tetracyanobenzene (TCNB) was used as the electron acceptor and pyri...

Utilizing water molecules to regulate the luminescence properties of solid materials is highly challenging. Herein, we develop a strategy to produce water‐triggered luminescence‐switching cocrystals by coassembling hydrophilic donors with electron‐deficient acceptors, where 1,2,4,5‐Tetracyanobenzene (TCNB) was used as the electron acceptor and pyri...

In this study, we report the synthesis of a series of planar and helical dinaphthophenazines by cyclocondensation reactions between the newly developed 9,10-bis((triisopropylsilyl)ethynyl)anthracene-1,2-dione and different diamines. Their optoelectronic and electrochemical properties are studied by ultraviolet-visible (UV-vis) spectroscopy, fluores...

Bulk heterojunction (BHJ) structures prepared by coating mixed solutions of a donor and an acceptor have been used for efficient organic photovoltaics (OPVs), but this approach allows little control of the molecular orientations in the films. Herein we show that a sequential deposition strategy, in which the molecular acceptor is deposited sequenti...

A series of π-conjugated copolymers containing V-shaped electron-deficient units of triphenyleno[1,2-c:7,8-c′]bis([1,2,5]thiadiazole) (TPTz) or its non-fused precursor were synthesized. Both the ring fusion in TPTz and the proper spacer units between...

Heteroatom‐embedded [8]circulenes have emerged as novel functionalized heteronanographenes that show various promising functions such as bright fluorescence, charge transporting, and redox reactivities. An improved synthetic method of cyclic tetrapyrrole precursors has been developed by utilizing a reverse coupling strategy, from which opposite‐typ...

Hetero[8]circulenes have emerged as novel functionalized heteronanographenes that show various promising functions such as bright fluorescence, charge transporting, and redox reactivities. One of the effective synthetic strategy is the fold‐in type oxidative fusion reaction of ortho‐phenylene‐bridged cyclic tetrapyrroles, whose construction, howeve...

Herein, we describe a series of three sterically congested nitrogenated benzodipentaphenes, one of which shows a highly distorted aromatic backbone with an unprecedented double π-expanded helicene structure.

Hetero[8]circulenes are an interesting class of polycyclic heteroaromatic molecules having rigid and planar structures, which are promising in light of their potential applications for OLED, OFET and so forth. Whereas their synthetic methods have been developed in some specific cases, a facile synthetic protocol of novel hetero[8]circulenes with tu...

Hybrid nanorings composed of 2,5‐pyrrolylene, 2,5‐thienylene, and bridging ortho‐phenylene were synthesized by strategic cross‐coupling reactions, and their structures were unambiguously revealed by X‐ray diffraction analysis. These nanorings showed highly twisted structures in the solid‐state, while exhibiting symmetric ¹H NMR spectra, indicating...

Oxidative fusion reactions of ortho-phenylene bridged cyclic hexapyrrole 3 and hexathiophene 5 furnished novel closed helicenes in a selective manner. X-Ray diffraction analysis unambiguously revealed the structures to be closed pentaaza[9]helicene 4 as the longest azahelicene reported so far, and unexpected double helical structure of hexathia[9]/...

Cyclic hybrids consisting of alternately linked 2,5-pyrroly-lene and 3,4-thienylene units were synthesized by Suzuki-Miyaura cross-coupling reaction of 3,4-diborylthiophene with 3,4-bis(5-bromopyrrol-2-yl)thiophene with the RuPhos-PdCl precatalyst in low yields. The same coupling reaction with Boc-protected 3,4-bis(5-bromopyrrol-2-yl)thiophene affo...

Oxidative fusion reactions of ortho-phenylene bridged cyclic hexapyrrole 3 and hexathiophene 5 furnished novel closed helicenes in a selective manner. X-Ray diffraction analysis unambiguously revealed the structures to be closed pentaaza[9]helicene 4 as the longest azahelicene reported so far, and unexpected double helical structure of hexathia[9]/...

The IR spectrum of a recently synthesized tetraaza[8]naphthylene (4N) molecule has been investigated and completely interpreted based on the calculation of the molecular structure and force field within the density functional theory (DFT) using the B3LYP/6-311G(d,p) method. The calculation has also successfully explained the X-ray diffraction data....

The synthesis of tribenzotriazasumanene was attempted on the basis of the "fold-in" synthesis of cyclic pyrrole trimer 5 and its analogues under oxidative and reductive conditions. While unexpectedly triply-fused product 6 was obtained in the oxidation of 5 with FeCl3 and AgOTf, the reductive coupling of hexabromo-tri-N-methylpyrrole trimer 9 furni...

ortho-Phenylene-bridged cyclic trimeric oligopyrrole C3 and hexameric oligopyrrole C6 were synthesized by Suzuki-Miyaura coupling reactions. The twisted structures of C3 and C6 were unambiguously revealed by X-ray diffraction analysis. The optical properties of these cyclic oligopyrroles were compared with linear oligopyrrole L3 and cyclic tetramer...

To deeply explore the interplay between molecular structure and near-infrared electrochromism of anthraquinone imides, two pairs of unsubstituted isomers (Ia and Ib) and nitro-substituted isomers (IIa and IIb) of anthraquinone imides were synthesized, in which the molecules Ia and IIa took more linear shapes than Ib and IIb. Cyclic voltammetry and...

The large redshift of near-infrared (NIR) absorptions of nitro-substituted anthraquinone imide (Nitro-AQI) radical anions, relative to other AQI derivatives, is rationalized based on quantum chemical calculations. Calculations reveal that the delocalization effects of electronegative substitution in the radical anion states is dramatically enhanced...

A series of novel donor-acceptor molecules (TPA-AQI, TPA-AQI2 and TPA-AQI3) with various number of electron-accepting anthraquinone imide (AQI) arms connected to the electron-donating triphenylamine (TPA) core were synthesized and characterized by UV–vis absorption spectroscopy, cyclic voltammetry and spectroelectrochemical measurements. The geomet...

Computational analysis predicts that intramolecular charge transfer (ICT) exists in anthraquinone imide (AQI) derivatives with electron-donating substituents at the 6-position, such as 4-methoxylphenyl, 4-N,N-dimethylaminophenyl, and thiophene. However, for those with electron-withdrawing ones, no clear ICT interaction could be observed. We predict...

A series of anthraquinone‐imide‐based dimers, C5*‐AQI‐Si2, C5*‐AQI‐Si3, C5*‐AQI‐Si4, and C5*‐AQI‐Si8, have been prepared by the hydrosilylation of N ‐(hex‐5‐enyl)‐6‐(4′‐(( S )‐2‐methylbutoxy)phenyl)anthraquinone‐2,3‐dicarboxylic imide and hydride‐terminated siloxanes with different lengths. Their liquid crystalline behaviors, and piezochromic and n...