阿德福韦双L-氨基酸酯与葫芦脲的主客体化学与抗乙型肝炎病毒活性研究

用1HNMR、荧光光谱和红外光谱方法研究阿德福韦双L-苯丙氨酸丙酯(FH-1)与改性六元葫芦脲(TMeQ[6])、七元葫芦脲(Q[7])以及八元葫芦脲(Q[8])的相互作用,探讨主客体作用位点及其识别机制.1HNMR图谱表明FH-1中苯丙氨酸残基部分进入葫芦脲的空腔内部受到屏蔽作用,而FH-1其它部分则位于葫芦脲端口外侧.荧光图谱表明FH-1与TMeQ[6],Q[7]与Q[8]分别形成1∶1或2∶1,1∶1或3∶1与2∶1的主客体包结配合物.红外光谱表明Q[7]与FH-1固体包合物发生了主客体相互作用,FH-1特征峰消失.吸湿性考察发现FH-1与Q[7]形成的固体包合物的吸湿稳定性明显提高,室温放置90d后仍然为白色固体.抗乙型肝炎病毒研究提示葫芦脲具有明显降低化合物细胞毒性,增加其抗病毒活性与作用选择性的效果.     

全自动食品甲醛分析仪的研制及应用

将超声提取、过滤和流动注射装置耦合,由自行设计的集成电路和软件控制,研制了一种全自动食品甲醛分析仪,实现了样品中甲醛提取—过滤—检测的连续自动化。利用在强碱性条件下,甲醛与间苯三酚快速发生显色反应,建立了测定食品中甲醛含量的测定方法,方法线性范围为0.5～20.0μg/mL,检出限为0.04μg/mL。用该法对水发海参、水发鸡爪、鹅肠和牛百叶样品进行了测定,测定结果在0.28～0.76μg/g之间(u=2,95%置信水平),样品加标回收率为88.7%～104%。该法适用于现场样品的快速测定。     

Theoretical Studies of the Reactions CFxH3−xCOOR+Cl and CF3COOCH3+OH

The mechanism and kinetics of the reactions of CF₃COOCH₂CH₃, CF₂HCOOCH₃, and CF₃COOCH₃ with Cl and OH radicals are studied using the B3LYP, MP2, BHandHLYP, and M06‐2X methods with the 6‐311G(d,p) basis set. The study is further refined by using the CCSD(T) and QCISD(T)/6‐311++G(d,p) methods. Seven hydrogen‐abstraction channels are found. All the rate constants, computed by a dual‐level direct method with a small‐curvature tunneling correction, are in good agreement with the experimental data. The tunneling effect is found to be important for the calculated rate constants in the low‐temperature range. For the reaction of CF₃COOCH₂CH₃+Cl, H‐abstraction from the CH₂ group is found to be the dominant reaction channel. The standard enthalpies of formation for the species are also calculated. The Arrhenius expressions are fitted within 200–1000 K as k_T(1)=8.4×10^?20T ^2.63exp(381.28/T), k_T(2)=2.95×10^?21T ^3.13exp(?103.21/T), k_T(3)=1.25×10^?23T ^3.37exp(791.98/T), and k_T(4)=4.53×10^?22T ^3.07exp(465.00/T).     

Effects of Preparation Method on the Performance of Ni/Al2O3 Catalysts for Hydrogen Production by Bio-Oil Steam Reforming

Steam reforming of bio-oil derived from the fast pyrolysis of biomass is an economic and renewable process for hydrogen production. The main objective of the present work has been to investigate the effects of the preparation method of Ni/Al₂O₃ catalysts on their performance in hydrogen production by bio-oil steam reforming. The Ni/Al₂O₃ catalysts were prepared by impregnation, co-precipitation, and sol?Cgel methods. XRD, XPS, H₂-TPR, SEM, TEM, TG, and N₂ physisorption measurements were performed to characterize the texture and structure of the catalysts obtained after calcination and after their subsequent use. Ethanol and bio-oil model compound were selected for steam reforming to evaluate the catalyst performance. The catalyst prepared by the co-precipitation method was found to display better performance than the other two. Under the optimized reaction conditions, an ethanol conversion of 99% and a H₂ yield of 88% were obtained.     

Synthesis of chiral γ-lactones via a RuPHOX-Ru catalyzed asymmetric hydrogenation of aroylacrylic acids

An asymmetric hydrogenation of aroylacrylic acids catalyzed by RuPHOX-Ru catalyst has been developed, affording the corresponding chiral γ-lactones in high yields and with up to 93% ee. The methodology has the advantage of utilizing easily accessible substrates and has therefore expand the scope of the resulting chiral γ-lactones. Furthermore, high catalytic efficiency was achieved in that the reduction of both the CC and CO double bonds was achieved in one step. The current work provides an alternative and convenient pathway for the synthesis of a wide range of chiral γ-lactones.     

I2O5 promoted iodosulfenylation of indoles under metal-free conditions

A mild, efficient, and metal-free strategy to construct 2-iodo-3-arylthioindoles was developed via I₂O₅-promoted iodosulfenylation of indoles utilizing simple, cheap and easily available thiophenols as sulfur sources. It is the first time that the iodothiolation difunctionalization of indoles at C-2 and C-3 positions was accomplished with the formation of 2-iodo-3-arylthioindoles in moderate to good yields.     

A facile and efficient method for synthesis of β-iodocarboxylates from terminal epoxides

A facile and efficient method has been developed for synthesis of β-iodocarboxylates in the presences of Ph₃P/I₂. Starting from epoxides, a series of β-iodocarboxylate compounds can be directly obtained in toluene media with excellent yields. Moreover, the method was successfully applied for the late-stage modification of natural products, such as isosteviol and vincamine derivatives, achieving the corresponding β-iodocarboxylates in good yields.     

A chlorinated non-fullerene acceptor for efficient polymer solar cells

Improving the performance and reducing the manufacturing costs are the main directions for the development of organic solar cells in the future. Here, the strategy that uses chemical structure modification to optimize the photoelectric properties is reported. A new narrow bandgap (1.30 eV) chlorinated non-fullerene electron acceptor (Y15), based on benzo[d][1,2,3] triazole with two 3-undecyl-thieno[2′,3′:4,5] thieno[3,2-b] pyrrole fused -7-heterocyclic ring, with absorption edge extending to the near-infrared (NIR) region, namely A-DA'D-A type structure, is designed and synthesized. Its electrochemical and optoelectronic properties are systematically investigated. Benefitting from its NIR light harvesting, the fabricated photovoltaic devices based on Y15 deliver a high power conversion efficiency (PCE) of 14.13%, when blending with a wide bandgap polymer donor PM6. Our results show that the A-DA'D-A type molecular design and application of near-infrared electron acceptors have the potential to further improve the PCE of polymer solar cells (PSCs).