A DFT study of the generation of interstellar species XN (X = Cl, and Br) activated by molecular sieve clusters

A cluster DFT (B3LYP) calculation study of ClN₃ and BrN₃ dissociation pathways catalyzed by molecular sieve is reported. A three-tetrahedral molecular sieve cluster (Al(OHSiH₃)(OSiH₃)(OH)₂, called T3) has been chosen in this study. Triplet-state products ClN and BrN are more easily produced with T3 molecular sieve cluster. Although the potential energy surfaces with T3 molecular sieve cluster are similar with those without T3 molecular sieve cluster, the dissociation process of ClN₃ and BrN₃ with T3 molecular sieve cluster becomes easier, which can be attributed to smaller energy gaps from the ground state reactant to the intersystem crossing point.     

Synthesis of a highly hindered hydrindanone via alpha-carbonyl radical cyclization: enantiospecific formal syntheses of (-)-pinguisenol and (-)-alpha-pinguisene

An enantiospecific synthesis of Schinzer's ketone 3 from (R)-(+)-pulegone via alpha-carbonyl radical cyclization was accomplished. This work also constitutes an enantiospecific formal syntheses of (-)-pinguisenol and (-)-alpha-pinguisene. The intermediate ketone 4 would be useful for the synthesis of other pinguisane-type sesquiterpenes.     

Novel determination of the dimerization mechanism for thermal polymerization of α-methylstyrene

This study discussed the phenomena on thermal polymerization of α-methylstyrene (AMS). A curve scanned by temperature-programmed technique was performed by differential scanning calorimetry (DSC). Heat of polymerization (ΔH) and onset temperature of exothermic (T₀) behavior were determined to be 280±10 J g^-1 and about 138±1°C, respectively. A dimer formation mechanism was proposed for initiation of the propagating chain. Spectroscopic identification of dimer structure was conducted by infrared (IR) spectroscopy in the wavenumber from 650 to 1100 cm^-1associated with molecular fingerprint characteristics. The mechanism of thermal polymerization on α-methylstyrene proposed in this study was similar to that of styrene suggested by Mayo.     

Solar Photocatalytic Degradation of 4‐Chlorophenol in Kaolinite Catalysts

This research applies semiconductor photocatalysts, which are formed by metal ion exchange on the surface of kaolinite catalyst with cations, to the study of photocatalytic degradation of 4‐chlorophenol. The analysis results of catalyst properties shows that, after sintering at 400 °C, kaolinite catalyst has a particle size of between 10–100 nm indicating the nano level of synthesized catalysts. Under the same condition, kaolinite‐Ag/Zn catalyst works better in degradation efficiency than single kaolinite‐Ag and kaolinite‐Zn catalysts. Kaolinite‐Zn catalyst declines in degradation efficacy after 150 minutes and performs poorer than the other three types of kaolinite catalysts. In the experiments of different amounts of catalysts, when the concentration exceeds 0.1 wt%, utilization of light energy and degradation efficiency will be reduced due to shielding effect. When at different pH values, the higher the pH value, the more OH‐will be released and that is beneficial for reaction with substances and the increase of reaction rate. Finally multivariate analysis proves that there is one determining factor that influences the photocatalytic degradation of 4‐chlorophenol in kaolinite catalysts, named as “the factor with intermediates competition degree,” the one affecting the 4‐CP degradation at different weight percentages that is referred to as the “shielding effect factor.”     

NMR and Excess Volumes Studies in DMF–Alcohol Mixtures

Chemical shifts of the alcohol and DMF protons in DMF–alcohol mixtures with the mole fraction of alcohol are reported in order to study the hydrogen bond interaction present in the mixtures. The densities of DMF–methanol mixture at 22°C are also measured. Excess volumes and excess chemical shifts are correlated by the Redlich–Kister equation. The relation between excess volumes and excess chemical shifts in the mixtures is discussed. It is found that the maximum excess chemical shifts ^E(CHO-OH) and ^E(CH₃-OH) are positioned at about mole fraction methanol = 0.57 for the DMF–methanol system, as is V ^E. The results show that the NMR spectral method offers a valuable approach to similar future studies of interactions in mixtures.     

置换法测定气液平衡

本文工作在流通法的原理上提出一种不分析组成测定汽液平衡的新方法。它通过配置样品与汽液平衡测定仪汽相浓度区或液相浓度区的等体积置换,测定配样组成所对应的露点或泡点。置换法的基本原理双循环汽液平衡测定仪在达到操作稳态时,存在着三个浓度区间的划分以及相互之间的物料平衡关系。流通法的基本作法是,将平衡液相回流或平衡汽相回流引出,并以等流量的配制样品注入混合区。溶质量随时间的变化规律为,     

（PdCl2—PVP）／Al2O3催化剂中Pd状态的探讨

氯化钯先锚定在聚乙烯吡咯烷酮上后进一步负载到Al_2O_3上所制的催化剂[简称(PdCl_2-PVP)/Al_2O_3]是一种活性、选择性高,稳定性好的烯烃、二烯烃和多烯烃加氢催化剂。本文结合加氢反应,使用XPS、FT-IR、电镜及用CO为探针的FT-IR,对这种催化剂进行了考察。实验说明,在这种催化剂中,钯的价态是在0—2之间。红外光谱在486cm~(-1)处有一微弱的小峰,说明存在Pd—N的配位键。催化剂中钯含量低时(0.2wt％)稳定性好,不吸附CO,活性中心是络合钯原子;当钯含量较高时(0.7wt％),催化剂的初活性虽不低,稳定性却较差,这种催化剂能吸附CO,IR谱图上仅在1919cm~(-1)处有CO桥式吸附态的伸缩振动。表明除络合钯原子外,还有聚集的钯金属存在。FT-IR尚表明,PVP在Al_2O_3上可能并非单纯的物理吸附。电镜结果表明,PVP在Al_2O_3上呈30—70(?)的微球状,(PdCl_2-PVP)/Al)_2O_3上的(PdCl_2-PVP)亦呈微球状,与前者无明显区别,这种催化剂中其活性中心是络合钯原子。     

The Effects of M2O3 on Stabilizing Monocopper over the Surface of Cu-ZnO-M2O3 Catalysts for Mathanol Synthesis

The effects of M₃O₃ (M = Al, Sc etc.) in Cu-ZnO-M₂O₃ catalysts on methanol synthesis at low pressure were studied with ESR, XPS and TPR spectroscopy. The results of ESR showed that the generation of monovalent cationic defects was because the valence state and electronic charge on the ZnO lattice lost their balance as M³⁺ doped into ZnO. The induced effect by Sc³⁺ is stronger than that by Al³⁺. The results of XPS and TPR indicated that the amount and stabilization of Cu⁺ on the surface of reduced copper-based catalyst and its catalytic activity were affected by the monovalent cationic defects on the surface of ZnO.     

四碘代对苯二甲酸根桥联的双钴(II)配合物的研究

报导了四种新的双核钴（Ⅱ）配合物，即［Co2（4I-TPHA）（L）4］（COl4）（4I-TPHA＝四碘代对苯二甲酸根阴离子，L＝1，10菲咯啉（phen）（1），5-硝基-,10菲咯啉（NO2-phen）（2），2，2′-联吡啶（bpy）（3）和4，4′-二甲基-2，2′-联吡啶（Me2bpy）（4）的合成和表征，配合物的磁性研究表明双核钴（Ⅱ）离子间有弱的反铁磁性自旋交换相互作用。