Theoretical Study on the Adsorption and Decomposition of Methanol over the Pt-Mo（111）/C Surface

The density functional theory(DFT) and self-consistent periodic calculation were used to investigate the methanol adsorption on the Pt-Mo(111)/C surface.The adsorption energies,equilibrium geometries and vibration frequencies of CH3OH on nine types of sites on the Pt-Mo(111)/C surface were predicted and the favorite adsorption site for methanol is the top-Pt site.Both sites of valence and conduction bands of doped system have been broadened,which are favorable for electrons to transfer to the cavity.The possible decomposition pathway was investigated with transition state searching and the calculation results indicate that the O-H bond is first broken,and then the methanol decomposes into methoxy.The activation barrier of O-H bond breaking with Pt-Mo catalyst is only 104.8 kJ mol-1,showing that carbon supported Pt-Mo alloys have promoted the decomposition of methanol.Comparing with the adsorption energies of CH3OH on the Pt(111)/C surface and that of CO,the adsorption energies of CO are higher,and Pt(111)/C is liable to be oxidized and loses the activity,which suggests that the catalyst Pt-Mo(111)/C is in favor of decomposing methanol and has better anti-poisoning ability than Pt(111)/C.     

Co-crystallization of Resorcin[4]arene Tetracarboxylic Acid with Triethylamine: Synthesis and Crystal Structure

Treatment of resorcin[4]arene tetracarboxylic acid 1 with triethylamine in the presence of Co(CH3COO)2·4H2O and 4,4'-bipyridine gave a co-crystallization 14-·4Et3NH+(C32H20O164-·4Et3NH+,Mr=1069.27) from ethanol and water.The compound was structurally determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic,space group P21/n,with a=8.1763(18),b=12.913(3),c=28.724(7) ,β=97.574(4)o,V=3006.3(12) 3,Z=2,Dc=1.181 g/cm3,F(000)=1152,Rint=0.0275,T=293(2) K,μ=0.086 mm-1,the final R=0.0634 and wR=0.1752 for 5082 observed reflections with Ⅰ 2σ(Ⅰ).The co-crystallization is very stable at room temperature.Possibly,a network of N-H···O(=C) plays an important role in the structure.Meanwhile,the compound emits a weak cyan luminescence with peak maximum band at 458 nm.     

一维链状锰配位聚合物[Mn(1,5-nds)(Him)_4]_n的合成、晶体结构及热稳定性研究(英文)

The synthesis,structural characterization and thermal behavior of a novel one-dimensional manganese (Ⅱ) complex of formula [Mn(1,5-nds)(Him)4]n [1,5-nds=naphthalene-1,5-disulfonate,Him=imidazole] is reported.The complex crystallizes in the triclinic system,space group P1,with a=0.835 42(13) nm,b=0.983 45(18) nm,c= 0.987 42(19) nm,α=60.523 0(10)°,β=97.748(2)°,γ=87.189(2)° and Z=2.The 1,5-nds ligand assumes the μ2 coordination mode and interlinks Mn(Ⅱ) ions into infinite one-dimensional chain structure along [111] direction,with the adjacent Mn…Mn distance being 1.144 99(12) nm.The chains are assembled into a three-dimensional supramolecular architecture via hydrogen bonds and C-H…π interactions.IR spectra and thermal analysis data are in agreement with the crystal structure.     

一维聚合物{[Co(N3)2(dps)2]·0.5H2O}n的合成，结构和磁性质

A coordination polymer {[Co(N₃)₂(dps)₂]·0.5H₂O}_n (1) (dps=dipyridin-4-ylsulfane) with one dimensional chains has been synthesized and the structure and magnetic properties were characterized. Complex 1 crystallizes belongs to monoclinic system and has space group P2₁/c. The Co^Ⅱ ion is six-coordinated and located at a compressed octahedral environment due to the Jahn-Teller effect. The ligand of dps bridges between Co^Ⅱ ions producing the infinite chains of Co…Co along a direction and, interestingly, four pyridyl groups of dps ligands form a propeller-shaped coordination geometry around Co^Ⅱ ion with the same spiral within the chain. These 1D chains are further linked through the hydrogen bonds to generate a 3D supermolecular network. Magnetic studies indicated that complex 1 shows very weak antiferromagnetic coupling between Co^Ⅱ ions in low temperature. CCDC: 769596.     

多孔载体上纯相MgAPO-36和CoAPO-36分子筛膜的合成与表征

<正>分子筛膜具有与常见气体和溶剂分子大小相当的规则孔道结构,良好的热稳定性和催化性能,可用于强化气体混合物分离[1-2]和膜反应过程[3-4]。到目前为止,沸石分子筛膜(如BEA、LTA和MFI型)和磷铝分子筛膜(如AEI、AFI和CHA型)相关的研究工作均有大量报道[5],但ATS型磷酸铝分子筛薄膜的合成与应用研究仍未见公开报导。     

超高效液相色谱-串联质谱法测定染发剂中7种酚类化合物

提出了应用超高效液相色谱-串联质谱法同时测定染发剂中4-氨基-2-硝基苯酚、3-二乙氨基酚、2-氨基-4-氯苯酚、2-氨基-5-硝基苯酚、2-氨基-3-硝基苯酚、1,7-二羟基萘酚和2,3-二羟基萘酚等7种酚类化合物的方法。采用甲醇萃取染发剂中酚类成分,经WatersAcquityUPLCTMBEHC18色谱柱分离,外标法定量,多反应监测模式采集质谱数据。7种酚类化合物的检出限(3S/N)均低于50.0μg.L-1。在10,20,50μg.g-1三个添加水平下,7种酚类化合物的回收率在68.8%～112.5%之间,相对标准偏差(n=6)在1.58%～12.61%之间。     

Solidified floating organic drop microextraction for determination of trace amounts of zinc in water samples by flame atomic absorption spectrometry

A glassy carbon electrode was prepared that was coated with a composite film containing electropolymerized poly(amidosulfonic acid) and multi-walled carbon nanotubes. It was used to study the electrochemical response of procaine by differential pulse voltammetry. The results indicate that the electrode exhibits a remarkable improvement in the oxidation peak of procaine, and this led to a simple and sensitive method for the electroanalytical determination of procaine. The peak current is proportional to the concentration of procaine from 80 nM to 1.0 µM. The detection limit is 25 nM (S/N?=?3). The modified electrode was successfully applied to the direct determination of procaine in pharmaceutical formulations.     

二甲基精氨酸二甲胺水解酶-1的理论研究

运用分子对接和分子动力学方法研究二甲基精氨酸二甲胺水解酶-1(DDAH-1)与其抑制剂亚胺基烯丁基-L-鸟氨酸(L-VNIO)和亚胺基丙基-L-鸟氨酸(Me-L-NIO)的相互作用和结合模式,并根据实验得到的结论设计了亚胺基苯乙基-L-鸟氨酸(Ph-L-NIO)抑制剂.结果表明:L-VNIO比Me-L-NIO对DDAH-1的抑制效果更强,这个结果与实验测得L-VNIO和Me-L-NIO对DDAH-1的半抑制浓度IC50值大小一致.Phe75、Asp78、His172、Ser175和Asp268这五个氨基酸残基在三种抑制剂形成的复合物中起到非常重要的作用,从计算结果推断在这三个抑制剂中我们设计得到的Ph-L-NIO对DDAH-1的抑制效果最好.     

Insight into herbicide resistance of W574L mutant Arabidopsis thaliana acetohydroxyacid synthase: molecular dynamics simulations and binding free energy calculations

Acetohydroxyacid synthase (AHAS) is the target enzyme of several classes of herbicides, such as sulfonylureas and imidazolinones. Now many mutant AHASs with herbicide resistance have emerged along with extensive use of herbicides, therefore it is imperative to understand the detailed interaction mechanism and resistance mechanism so as to develop new potent inhibitors for wild-type or resistant AHAS. With the aid of available crystal structures of the Arabidopsis thaliana (At) AHAS-inhibitor complex, molecular dynamics (MD) simulations were used to investigate the interaction and resistance mechanism directly and dynamically at the atomic level. Nanosecond-level MD simulations were performed on six systems consisting of wild-type or W574L mutant AtAHAS in the complex with three sulfonylurea inhibitors, separately, and binding free energy was calculated for each system using the MM-GBSA method. Comprehensive analyses from structural and energetic aspects confirmed the importance of residue W574, and also indicated that W574L mutation might alert the structural charactersistic of the substrate access channel and decrease the binding affinity of inhibitors, which cooperatively weaken the effective channel-blocked effect and finally result in weaker inhibitory effect of inhibitor and corresponding herbicide resistance of W574L mutant. To our knowledge, it is the first report about MD simulations study on the AHAS-related system, which will pave the way to study the interactions between herbicides and wild-type or mutant AHAS dynamically, and decipher the resistance mechanism at the atomic level for better designing new potent anti-resistance herbicides.     

Comparison of RP, Ion-Pair and IE Chromatography Coupled with UV and Tandem Mass Spectrometry for the Determination of 8-Hydroxyquinoline in Cosmetics

Liquid chromatographic methods based on reversed-phase, ion-pair and ion-exchange chromatography coupled with ultraviolet spectrometry and tandem mass spectrometry have been developed and compared for the determination of 8-hydroxyquinoline in cosmetic samples. The individual parameters of different techniques are systematically optimized. The reversed-phase chromatography using ultrasonic extraction, centrifugation and filtration prior to LC–UV and LC–MS–MS detection was selected to be the general analytical method for the routine analysis of 8-hydroxyquinoline in cosmetics due to its simplicity, column reproducibility and sensitivity. The procedure is rapid, simple and suitable for the quality control of cosmetic preparations. The application of this technique to the assay of commercial products is also presented.