A fused-ring electron acceptor IDT-2BR1 based on indacenodithiophene core with hexyl side-chains flanked by benzothiadiazole rhodanine was designed and synthesized.In comparison with its counterpart with hexylphenyl side-chains(IDT-2BR),IDT-2BR1exhibits higher highest occupied molecular orbital(HOMO)energy but similar lowest unoccupied molecular orbital(LUMO)energy(IDT-2BR1:HOMO=-5.37eV,LUMO=-3.67eV;IDT-2BR:HOMO=-5.52eV,LUMO=-3.69eV),red-shifted absorption and narrower bandgap.IDT-2BR1 has higher electron mobility(2.2×10^(-3)cm^2 V^(-1)s^(-1))than IDT-2BR(3.4×10^(-4)cm^2 V^(-1)s^(-1))due to the reduced steric hindrance and ordered molecular packing.Fullerene-free organic solar cells based on PTB7-Th:IDT-2BRl yield power conversion efficiencies up to 8.7%,higher than that of PTB7-Th:IDT-2BR(7.7%),with a high open circuit voltage of0.95 V and good device stability.
The luminogens with aggregation-induced emission(AIEgens) characteristics have been widely applied in diverse areas. However,the n-type AIEgens are to be further developed. In this paper, we designed and synthesized an n-type multifunctional AIEgen of tetraphenylethene-substituted 3,4,5-triphenyl-4H-1,2,4-triazole(BTPE-TAZ). This AIEgen can serve as both light-emitting and electron-transporting layers in organic light-emitting devices. Moreover, it also exhibits the interesting optical waveguide and reversible mechanochromic luminescence properties, which are of great potential for practical applications.
The research on using thiol-ene click reaction to synthesize sulfur-containing polymers with topological structures and advanced functional properties is a hot topic. However, the application of the thiol-yne reaction in the functional polymer preparation is limited and the thiol-yne click polymerization is to be further developed. In this review, we summarized recent research efforts on using thiol-yne click polymerization to synthesize polymers with topological structures. The sulfur-containing polymers were facilely prepared by photo-and thermo-initiated, amine-mediated, and transition-metal-catalyzed thiol-yne click polymerizations. These polymers are promising to be used as drug-delivery vehicles, high refractive index optical materials, photovoltaic materials, and biomaterials etc.
A label-free fluorescent aptasensor for specific and ultrasensitive monitoring ochratoxin A（OTA） was developed using the specific aptamer of OTA（OSA） as recognition dement, an aggregation-induced emission（AIE） molecule（a 9,10-distyrylanthracene with two ammonium groups, DSAI） as a fluorescent probe, and graphene oxide（GO） as a quencher. In the absence of OTA, the AIE probe DSAI and OSA complex（DSAI/OSA） is adsorbed on the GO surface, and the fluorescence of DSAI will be quenched efficiently via the fluorescence resonance energy transfer（FRET） from DSAI to GO. Upon the OTA addition, a more stable complex（OSA-OTA） is formed and released from GO. Meanwhile, DSAI and OSA-OTA can form a new complex（DSAI/OSA-OTA）, then the fluorescent signal of DSAI recovers gradually. Therefore, by introducing GO and DSAI, the fluorescence signal of DSAI can be easily turned from ＂off＂ to ＂on＂ after the addition of OTA, and the ultrasensitive detection of OTA by monitoring the change of the fluorescence signal of DSAI can be readily realized. The detection limit of the assay can reach 0.324 nmol/L with a linear detection range of 10-200 nmol/L. And the aptasensor exhibits high selectivity for OTA against other analogues. Moreover, it has been successfully applied for the detection of OTA in red wine samples.
Two 9,10-distyrylanthracene (DSA) derivatives CNDSA and t-BUDSA were designed and synthesized, and their photophysical properties and crystal structures were investigated. Compared to DSA, the maximum emission peaks of the two compounds showed red-shift not only in THF solution, but also in crystals, because the introduction of electron-withdrawing substituents to DSA leads to more dispersion of the electrons in the molecules. The two crystals of CNDSA and t-BUDSA show strong fluores- cence with the efficiency F of 45% and 33%, respectively, which may be resulted from no obvious-interactions between molecules inside the crystal due to the large distance between the two adjacent molecules and nearly no overlap between the central anthracene planes. The analysis of crystal structures of the two compounds indicated that the molecules are arranged in the same conformation and orientation in their crystals, i.e. uniaxially oriented packing crystal, because of the supramolecular interac- tion of CH/ in the two crystals and additional C-H···N interactions in CNDSA.
The last decade has witnessed the quick develop of self-healing materials. As a newborn strategy, the alternative of irreversible covalent bond formation is, however, to be further developed. In this paper, self-healing hyperbranched poly(aroxycarbonyltriazole)based on such mechanism were prepared by our developed metal-free click polymerization of simplified dipropiolate and triazide. Thanks to their excellent processability and film-forming ability, high quality homogeneous films free from defects were obtained by casting. The cut films could be healed by stacking or pressing the halves together at room temperature and elevated temperature. Thus, this design concept for self-healing materials should be generally applicable to other hyperbranched polymers with reactive groups on their peripheries.
