Tianzhi Yu,Haifang Chai,Yuling Zhao,Chengcheng Zhang,Peng Liu,Duowang Fan
Two new mononuclear Cu(I) complexes based on 2-(2′-pyridyl)benzimidazolyl derivative ligand containing hole-transporting carbazole ( L ), [Cu(L)(DPEphos)](BF 4 ) and [Cu(L)(PPh 3 ) 2 ](BF 4 ), where L = (4-(9 H -carbazol-9-yl)phenyl)methyl-2-(2′-pyridyl)benzimidazole; DPEphos = bis[2-(diphenylphosphino)phenyl]ether and PPh 3 = triphenylphosphine, have been synthesized and characterized on the basis of elemental analysis, 1 H NMR and FT-IR spectra. The structures of the ligand L and the Cu(I) complexes were characterized by single crystal X-ray diffraction. The results reveal that in the Cu(I) complexes the central Cu(I) ions assume the irregular distorted tetrahedral geometry and are tetra-coordinated by the two nitrogen atoms from L ligand and two phosphorus atoms from ancillary ligands. The photophysical properties of the complexes were examined by using UV–vis, photoluminescence spectroscopic analysis. The complexes exhibit weak MLCT absorption bands ranging from 360 to 480 nm, and display strong orange phosphorescence in the solid states at room temperature, which is completely quenched in solutions.
In the technological development of anion exchange membrane fuel cells (AEMFCs), it is crucial to prepare anion exchange membranes (AEMs) with high conductivity and excellent dimensional stability. This study successfully developed highly branched poly(aryl piperidinium) AEMs by introducing 4,4′-bis(N-carbazolyl)-1,1′-biphenyl as branched linker unit into the poly(p-terphenyl piperidinium) backbone. With the introduction of the carbazole group, the plane-conjugated structure and non-rotatable properties are fully utilised, which effectively reduces the entanglement between the polymer backbones and increases the free volume of the AEMs, hence facilitates the construction of an efficient ion transport channel. The branched structure effectively reduces the water uptake of the membrane which leads to improved dimensional stability. The optimized QPCBP-TP-7 membrane exhibited high conductivity, reaching up to 151.88 mS cm −1 at 80 °C, along with excellent mechanical strength (TS = 42.51 MPa, EB = 13.32 %, wet state) and dimensional stability (SR of 22.9 % at 80 °C). Surprisingly, this membrane also exhibited favorable antioxidant properties (retaining over 97.28 % weight after 96 h in Fenton's reagent at 80 °C), and alkaline stability (retaining over 86.81 % efficacy after 1500 h in 5 M NaOH solution at 80 °C). In AEMFCs applications, the QPCBP-TP-7 membrane achieved peak power density (PPD) up to 616 mW cm −2 with the current density is 1330 mA cm −2 at 80 °C (H 2 -O 2 ) and the QPCBP-TP-7 membrane remained stable and hardly degraded when operated at constant current of 0.1 A cm −2 (80 °C) over 100 h.
Wang Weiqi,Wang Fan,Wang Yuqing,Zhang Lili,Okamoto Yoshio,Shen Jun
Four cellulose derivatives bearing benzothienyl or carbazolyl fluorophore pendants were successfully synthesized through carbamoylation followed by Steglich esterification or only esterification process, respectively. The enantioselective fluorescent sensing properties of the obtained derivatives were then evaluated using eight chiral substrates, including chiral aromatic amines and chiral amino alcohol-based drug intermediates. The four bulky host macromolecules exhibited good enantioselective fluorescence response to most of the tested guests with high enantioselectivity and sensitivity. Especially, a high enantiomeric fluorescence difference ratio ( ef = 37.16) was achieved on cellulose tris(2-benzothienylformate) ( Cel - 3 ) for the α-methylbenzylamine ( Q2 ), an important chiral agricultural drug intermediate. Worthy to be mentioned, an interesting opposite fluorescence response and a dual fluorescence enhancement pattern were also observed on the benzothienyl derivative Cel - 3 for the enantiomer pairs of 1-(4-methoxyphenyl) ethylamine ( Q3 ) and phenylglycinol ( Q6 ), a critical intermediate for chiral drug as an antilipemic agent in high demand, respectively. It indicated that the bulky Cel - 3 possessed excellent enantioselective fluorescent sensing properties to the chiral aromatic amine and amino alcohols, revealing good potential as efficient chiral fluorescent sensors. It was speculated that a beneficial chiral domain may be constructed by the appropriate arrangement of bulky conjugated benzothienyl or carbazolyl pendants on the phenylcarbamates or esters surrounding the helical backbone of cellulose, which was crucial for the efficient chiral fluorescent sensing performance. The introduction of bulky fluorophore pendants on the cellulose phenylcarbamates or esters presents an efficient strategy to produce effective chiral fluorescent recognition materials. Graphical Abstract
危险品化学品经营许可证（带存储）