期刊：
Journal of Physical Chemistry Letters,2019年10(20):6219-6226 ISSN：1948-7185
通讯作者：
Tang, Jianfeng;Prezhdo, Oleg V.
作者机构：
[Tang, Jianfeng; Li, Wei] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Vasenko, Andrey S.] Natl Res Univ Higher Sch Econ, Moscow 101000, Russia.;[Prezhdo, Oleg V.] Univ Southern Calif, Dept Chem, Los Angeles, CA 90089 USA.
通讯机构：
[Tang, Jianfeng] H;[Prezhdo, Oleg V.] U;Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;Univ Southern Calif, Dept Chem, Los Angeles, CA 90089 USA.
摘要：
Lead halide perovskites constitute a very promising class of materials for a broad range of solar and optoelectronic applications. Perovskites exhibit many unusual properties, and recent experiments demonstrate an unusual temperature dependence of charge carrier lifetimes. Focusing on the all-inorganic CsPbBr3, and using a combination of ab initio nonadiabatic molecular dynamics and time-domain density functional theory, we demonstrate that the unconventional behavior arises because of a highly anharmonic nature of atomic motions in perovskites. As temperature increases, perovskite structure undergoes a notable deformation, reflected in tilting of octahedral units, and experiences large-scale anharmonic movements away from the equilibrium geometry. As a result, the electronic energy gap increases, and phonon-induced loss of coherence within the electronic subsystem accelerates. These two factors slow down nonradiative electron-hole recombination, which constitutes the main limitation on efficiencies of perovskite solar, optical, and electronic devices. The increase of charge carrier lifetimes with temperature is particularly beneficial in applications, because materials heat up, for instance, from sunlight during solar energy harvesting. The behavior of the all-inorganic halide perovskite investigated here is different from that of hybrid organic-inorganic perovskites, which exhibit additional disorder associated with reorientations of the asymmetric organic cations. The reported simulations generate an in-depth understanding of the unusual properties of inorganic perovskites, relevant for photocatalytic, photovoltaic, electronic, and optical applications.
摘要：
Herein, we have revealed elemental sulfur- and iodine reagent-mediated indole C3 arylations using cyclohexanones as the arylating reagent. This protocol provides an efficient gram-scalable access to 3-arylindole and benzo[4,5]thieno[2,3-b]indole motifs with a broad range of compatible functionalities.
摘要：
A three-component procedure for the preparation of 2-substituted benzothiazoles from nitroarenes, alcohols, and sulfur powder is described. The reaction showed a good functional group tolerance to provide the heterocyclic products in moderate to good yields. The sequential assembly involving nitro reduction, C–N condensation, and C–S bond formation has been realized in one pot.
期刊：
NEW JOURNAL OF CHEMISTRY,2019年43(15):6010-6020 ISSN：1144-0546
通讯作者：
Zhou, Wen;Zhou, Li
作者机构：
[Fu, Kaishuo; Yuan, Sisi; Zhou, Wen; Huang, Weiping; Li, MaoLin] Guangzhou Univ Chinese Med, Sch Pharmaceut Sci, Waihuan Rd, Guangzhou 510006, Guangdong, Peoples R China.;[Jiang, Zhilin] Puer Univ, Puer, Yunan, Peoples R China.;[Shi, Yonghui] Sun Yat Sen Univ, Sun Yat Sen Mem Hosp, Dept Pharm, Guangzhou 510120, Guangdong, Peoples R China.;[Chen, YongJun] Guangzhou Univ Chinese Med, South China Res Ctr Acupuncture & Moxibust, Med Coll Acu Moxi & Rehabil, Waihuan Rd, Guangzhou 510006, Guangdong, Peoples R China.;[Zhou, Li] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Zhou, Wen] G;[Zhou, Li] H;Guangzhou Univ Chinese Med, Sch Pharmaceut Sci, Waihuan Rd, Guangzhou 510006, Guangdong, Peoples R China.;Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
摘要：
The tumor-seeking role of bleomycin (BLM) disaccharide has been demonstrated to serve as a promising tool for cancer diagnosis and a potential ligand for targeted therapy. However, these practical applications are often hampered by the lack of BLM disaccharide. Herein, an efficient multi-gram synthesis of peracetylated BLM disaccharide 20 is achieved by a TMSOTF-mediated glycosidation coupling manner in 43.6% overall yield in terms of benzyl galactoside. The critical innovation of the synthetic strategy is that inexpensive benzyl galactoside was first adopted to prepare an l-gulose subunit 3 as a glycosyl acceptor, with a much shorter route in 73.0% yield, and a 3-O-carbamoyl-mannose donor 4 was achieved in 47.2% yield by lowering the amount of dibutyltin oxide, and merging aminolysis and selective deacetylation into a one-pot reaction. Next, the incorporation of BLM disaccharide into 10-hydroxycamptothecin (10-HCPT), a non-specific model compound, to form conjugate 1 could significantly improve the antitumor activity and display obvious selectivity toward cancerous and normal cells in comparison with 10-HCPT. Moreover, BLM disaccharide itself was non-cytotoxic, clearly indicating the importance and potential of BLM disaccharide in solving the targeted antitumor therapy of cytotoxic drugs.
通讯机构：
[Huang, Huawen] X;Xiangtan Univ, Coll Chem, Key Lab Green Organ Synth & Applicat Hunan Prov, Minist Educ,Key Lab Environm Friendly Chem & Appl, Xiangtan 411105, Peoples R China.
摘要：
A novel copper-catalyzed oxidative formal [3 + 2] annulations of ketoxime acetates and tetrohydroisoquinolines for the synthesis of fused pyrazoles and imidazoles has been developed. A broad range of important isoquinoline-fused pyrazole and imidazole products were selectively generated by the key control of oxidant.
摘要：
A DNA-templated copper nanoparticle (CuNP) probe has been developed for the determination of the human immunodeficiency virus oligonucleotide (HIV-DNA). The function of the probe relies on affinity binding-induced DNA hybridization associated with the use of double G-quadruplexes. Double-stranded DNA (dsDNA) with poly(AT-TA) bases was used as a template for synthesis of dsDNA-CuNPs. These have weak fluorescence. In the next step, two G-rich sequences that are linked to both sides of the ds-DNA are locked by HIV complementary DNA (cDNA). If HIV-DNA is introduced, it will hybridize with cDNA, thereby transforming the two G-rich sequences into G-quadruplexes. This enhances the fluorescence of the adjacent dsDNA-CuNPs. Fluorescence increases linearly in the 1 to 200 and 250-1000 nM HIV-DNA concentration range, and the detection limit is 13 pM. This enzyme-free fluorometric assay is time-saving, easily operated, and therefore has large potential in biosensing because it may be extended to various other DNA targets. Graphic abstract Double-strand DNA-templated copper nanoparticles (DNA-CuNPs) have weak fluorescence. When Human Immunodeficiency Virus oligonucleotide (HIV-DNA) is added, it completely hybridized with HIV complementary DNA (cDNA). As a result, the two exposed G-rich sequences are transformed into G-quadruplexes, and an apparent increase in the fluorescence intensity can be observed. (AA: ascorbic acid).
