化学合成植物病毒抑制剂研究进展

介绍了近年来植物病毒抑制剂的研究情况，作为植物病毒抑制剂的化合物主要可分为三大类：１）有机酸类，包括有机羧酸和有机磺酸；２）杂环化合物，包括生物碱、三唑衍生物、噻二唑衍生物、咪唑衍生物和三嗪衍生物等；３）脲类和硫脲类化合物。

Tungsten carbide-reduced graphene oxide intercalation compound as co-catalyst for methanol oxidation

Highly dispersed tungsten carbide（WC） nanoparticles（NPs） sandwiched between few-layer reduced graphene oxide（RGO） have been successfully synthesized by using thiourea as an anchoring and inducing reagent.The metatungstate ion,[H2W（12）O（40）]^6-,is assembled on thiourea-modified graphene oxide（GO） by an impregnation method.The WC NPs,with a mean diameter of 1.5 nm,are obtained through a process whereby ammonium metatungstate first turns to WS2,which then forms an intercalation compound with RGO before growing,in situ,to WC NPs.The Pt/WC-RGO electrocatalysts are fabricated by a microwave-assisted method.The intimate contacts between Pt,WC,and RGO are confirmed by X-ray diffraction,scanning electron microscope,transmission electron microscope,and Raman spectroscopy.For methanol oxidation,the Pt/WC-RGO electrocatalyst exhibited an electrochemical surface area value of 246.1 m^2/g Pt and a peak current density of1364.7 mA/mg Pt,which are,respectively,3.66 and 4.77 times greater than those of commercial Pt/C electrocatalyst（67.2 m^2/g Pt,286.0 mA/mg Pt）.The excellent CO-poisoning resistance and long-term stability of the electrocatalyst are also evidenced by CO stripping,chronoamperometry,and accelerated durability testing.Because Pt/WC-RGO has higher catalytic activity compared with that of commercial Pt/C,as a result of its intercalated structure and synergistic effect,less Pt will be required for the same performance,which in turn will reduce the cost of the fuel cell.The present method is facile,efficient,and scalable for mass production of the nanomaterials.

New tricks for an old dog: Visible light-driven hydrogen production from water catalyzed by fac-and mer-geometrical isomers of tris(thiosemicarbazide) cobalt(Ⅲ)

Increasing interest has been paid to the development of earth‐abundant metal complexes as promising surrogates of platinum for the electrocatalytically and photocatalytically driven hydrogen evolution reaction.In this work,we report on molecular H2‐evolving catalysts based on two octahedral complexes of cobalt thiosemicarbazide,fac‐[Co(Htsc)3]Cl3·3H2O(C1,Htsc=thiosemicarbazide)and mer‐[Co(Htsc)3]Cl3·4H2O(C2),which have facial(fac)and meridional(mer)geometry,respectively.Electrochemical studies confirmed that both C1and C2are active electrocatalysts in MeOH solution using acetic acid as the proton source,with the same overpotential of^640mV and TOF of^210s–1.The complex C1also exhibits electrocatalytic activity for hydrogen evolution reaction in aqueous media free of organic solvent with a moderate overpotential(560mV).Visible light‐driven hydrogen evolution experiments were carried out in combination with fluorescein as photosensitizer and triethylamine as sacrificial reductant in homogeneous environments.Our studies showed that both C1and C2can be used as efficient proton‐reduction catalysts in purely aqueous solution and have the same photocatalytic activities.A TOF of125h–1with a TON of900for photocatalytic H2generation using C1and C2in water were achieved for the noble‐metal‐free homogeneous system.It should be noted that this is the first reported study investigating the effect on the catalytic hydrogen production performance of using fac‐and mer‐isomers of molecular catalysts.

Synthesis and antiviral bioactivities of novel chiral bis-thiourea-type derivatives containing α-aminophosphonate moiety

Starting from 1-((1R,2R)-2-aminocyclohexyl)-3-substituted thioureas (3a–c) and substituted isothiocyanates (9a–d),chiral bis-thiourea derivatives containing α-aminophosphonate moiety 10a–l were prepared and completely characterized by elemental analysis,physical and spectral (IR,1H NMR,13C NMR,31P NMR) data.The results of bioassay revealed that compounds 10a and 10e possessed appreciable curative bioactivities on cucumber mosaic virus (CMV) at 0.5 mg/mL in vivo (inhibitory rate = 60.3%,64.8% respectively) and tobacco mosaic virus (TMV) at 0.5 mg/mL in vivo (inhibitory rate = 50.3%,50.8% respectively),which were comparable to the values shown by standard reference (58.7%) and commercial product Ningnanmycin (56.3%),respectively.Chiral compound 10e displayed more potent antiviral activity (EC50 = 0.149 mg/mL) than Ningnanmycin (EC50 = 0.201mg/mL) against CMV.

Thiourea Based Tweezer Anion Receptors for Selective Sensing of Fluoride Ions

Three 3,3＇-di（4-substituted-phenyl）-1,1＇-isophthaloylbis（thiourea） compounds were designed as novel neutral anion receptors, and synthesized by simple steps in good yields. The single crystal structure of receptor 1 shows that a solvent molecule was captured by the host molecule through intermolecular hydrogen bonding. Moreover, it was self-assembled as a supramolecular system for the presence of abundant inter- and intramolecular hydrogen bonding and π-π interactions between phenyl groups. Their application as anion receptors has been examined by UV-Vis and ^1H NMR spectroscopy, showing that they had a higher selectivity for fluoride than other halides. The host and guest formed a 1 ： 1 stoichiometry complex through hydrogen bonding interactions in the first step, then following a process of deprotonation in presence of an excess of F^- in the solvent of DMF.