Isomeric Effect of a π Bridge in an IDT-Based Nonfused Electron Photovoltaic Acceptor.

A pair of isomers, IDT-BOF containing S⋅⋅⋅O/F⋅⋅⋅H noncovalently configurational locks and IDT-BFO containing F⋅⋅⋅H/O⋅⋅⋅H noncovalently configurational locks, with an acceptor-π-donor-π-acceptor (A-π-D-π-A) structure have been designed and synthesized by choosing 4,9-dihydro-s-indaceno[1,2-b : 5,6-b']dithiophene (IDT) as the D unit, an F/n-hexyloxy substituted phenyl ring as π bridge, and 3-(dicyanomethylidene)indan-1-one as the A unit. Owing to the S⋅⋅⋅O/F⋅⋅⋅H or F⋅⋅⋅H/O⋅⋅⋅H noncovalently configurational locks, both IDT-BOF and IDT-BFO have a completely planar structure. IDT-BOF exhibits a similar LUMO to IDT-BFO, but higher HOMO energy levels, leading to a smaller optical bandgap and red-shifted absorption. However, IDT-BOF-based bulk-heterojunction organic solar cells (BHJ-OSCs) coupled with PBDB-T, and PCE-10 as donor materials both exhibited a lower PCE than that of IDT-BFO (PBDB-T: 5.2 vs. 6.1 %; PCE-10: 1.7 vs. 3.2 %). Comprehensively comparing and investigating IDT-BOF : PBDB-T and IDT-BFO : PBDB-T OSCs suggested that the large phase separation and serious charge recombination of IDT-BOF-based OSCs contributed to its lower power conversion efficiency. Importantly, ternary solar cells based on PBDB-T : Y5 as control devices with an additional 10 % IDT-BFO exhibited a 5 % enhancement in the PCE compared to the control device (14.3 vs. 13.46 %).

Al/CuO@CNFs Conductive Flexible Energetic Films with High Electrical Safety.

The development of energetic materials with both high energy and high safety has always been the focus of the field of energetic materials. In this paper, a low-current-sensitivity flexible energetic film composed of carbon nanofibers (CNFs)-coated Al/CuO metastable intermolecular composites (MICs) was prepared by a blow-spinning combined with controlled heat treatment technique. Hotspots can hardly generate in this kind of energetic film due to the increased electrical and thermal conductivity, leading to low sensitivity of MICs. It evenly stays at a high voltage (60 V) for 24 h without raising the temperature significantly. The energetic films keep the high energy release of MICs due to the additional violent reactions between CuO and CNFs as well as the light weight of CNFs, showing the heat release of 2864 J/g. In addition, the obtained films exhibit good mechanical properties and can maintain the structural integrity after 1000 cycles of repeated bending to a 6 mm curvature radius. The above characteristics reveal that energetic films presented in this paper have certain safety, high energy, and flexibility and have potential applications in transient electronics with flexible requirements such as micro-electromechanical system.

[Alpha-glucosidase inhibitory active constituents contained in nutshell of Trapa acornis].

OBJECTIVE: To study chemical constituents in nutshell of Trapa acornis and in vitro inhibitory activity against alpha-glucosidase. METHOD: EtOAC and n-butanol extractive fractions were separated by chromatography and their structures were identified by multiple spectroscopic techniques. RESULT: Nine compounds were separated, they were 4,23,24-trimethylcholest-22-en-3-ol (1), stigmasterol (2), alpha-amyrin (3), (+)-nyasol (4), oleanolic acid (5), ursolic acid (6), hederagenin (7), 3,23-dihydroxy-12-ursen-28-oic acid (8) and beta-daucosterol (9). Total extracts from T. acornis nutshells, petroleum ether fractions, acetic ether fractions and normal butanol fractions showed inhibitory activity against alpha-glucosidase. Compound 5 (IC50 2.88 mg x L(-1)) and 6 (IC50 4.42 mg L(-1)) showed stronger inhibitory activity against alpha-glucosidase. CONCLUSION: All compounds except compound 2 were separated from the genus for the first time, and compound 1-9 were separated from this plant for the first time.

[Research progress of ethanologenic Zymomonas mobilis].

Zymomonas mobilis is one of the natural ethanologenic microbes. With the unique Entner-Doudoroff pathway and some other special pathways of glycolytic and energetic metabolism, Z. mobilis has remarkable characters of higher rate of ethanol production and higher tolerance to ethanol. Glycolytic and energetic metabolism, tolerances (e.g., to ethanol, osmotic stress, etc.) and genetic improvements of Z. mobilis are reviewed to elucidate the huge potential of Z. mobilis in fuel ethanol production.

[Synthesis and antibacterial activity of 2-(3-pyridyl)-5-([(5-aryl-1,3,4-oxadiazol-2-yl) methylene]thio)-1,3,4-oxadiazoles].

AIM: Studies on synthesis and antibacterial activity of new heterocycles. METHODS: The cyclocondensation of [(3-pyridyl)-1,3,4-oxadiazol-2-yl] thio acetic acid with various aroyl hydrazines in the presence of POCl3 and xylene gave the corresponding titled compounds, and the in vitro antibacterial activity was primarily evaluated by the method of cupplate diffusion solution. RESULTS: Sixteen novel titled compounds were synthesized, their structures were confirmed by IR, 1HNMR, MS and elemental analysis. Biological screening results demonstrated that most of the compounds prepared displayed potential antibacterial activity. CONCLUSION: Oxadiazoles incorporting pyridyl oxadiazole ring may be usefully antibacterial candidate drugs.

[Effect of alcohol extract of pig bile on digestion system].

OBJECTIVE: To study effect of alcohol extract of pig bile(AEB) on digestion system. METHODS: Action of AEB in vitro and vivo were observed. RESULTS: AEB could suppress the spontaneous movement of isolated intestinal smooth muscles in rabbit, markedly antagonize the intestinal propelling movement of carbon ink and experimental diarrhea caused by castor oil in mice, obviously inhibit growth of microbe. CONCLUSIONS: AEB could improve the condition of digestion.

Experimental and theoretical study of three new benzothiazole-fused carbazole derivatives.

Three new D-π-A type compounds, each containing one benzothiazole ring as an electron acceptor and one N-ethylcarbazole group as electron donor, were synthesized and characterized by elemental analysis, NMR, MS and thermogravimetric analysis. The absorption and emission spectra of three compounds were experimentally determined in several solvents and were simultaneously computed using density functional theory (DFT) and time-dependent density functional theory (TDDFT). The calculated reorganization energy for hole and electron indicates that three compounds are in favor of hole transport than electron transport. The calculated absorption and emission wavelengths are well coincident with the measured data. The calculated lowest-lying absorption spectra can be mainly attributed to intramolecular charge transfer (ICT). And the calculated fluorescence spectra can be mainly described as originating from an excited state with intramolecular charge transfer (ICT) character. The results show that three compounds exhibited excellent thermal stability and high fluorescence quantum yields, indicating their potential applications as excellent optoelectronic material in optical field.