2-β-二酮-1,3,2-二苯并[d,f]和二萘并(α,β)[d,f]-二氧硼杂环庚二烯的合成与结构

本文报道1,3,2-二苯并[d,f]二氧硼杂环庚二烯和1,3,2-二萘并(α,β)[d,f]二氧硼杂环庚二烯的制备及其β-二酮衍生物—以硼为螺原子的螺环[6,5]化合物的合成与性质. 8个标题化合物均为新化合物, 具有与10-β-二酮-10, 9-硼氧杂菲类似的结构.     

可光固化单体2,7-二溴-9,9-双[4’-(3″-乙基-3″-氧杂环丁烷甲氧基己基氧基)苯基]芴的合成

以芴为原料,经溴代和氧化反应制得2,7-二溴芴酮(3);3与苯酚反应合成2,7-二溴-9,9-双(4’-羟基苯基)芴(4);4与3-(6’-溴己氧基甲基)-3-乙基氧杂环丁烷经醚化反应合成了可光固化单体2,7-二溴-9,9-双[4’-(3″-乙基-3″-氧杂环丁烷甲氧基己基氧基)苯基]芴,总收率67%,其结构经1H NMR,13C NMR和元素分析表征。     

螺环三代树形大分子化合物的合成

以对苯二甲醛单缩醛与季戊四醇反应得到了2,4,8,10-四氧杂-2,9-二(4-二氰基乙烯基苯基)螺[5.5]十一烷(1), 经水解, 再与丙二腈反应, 制备了中间体2,4,8,10-四氧杂-2-(4-二氰基乙烯基苯基)-9-(4-甲酰基苯基)螺[5.5]十一烷(3). 8-(4-氧代环己烷基)-1,4-二氧杂螺[4.5]癸烷经芳构化形成2,6,10-三-(4-氧代环己烷基)-1,2,3,4,5,6,7,8,9,10,11,12-十二氢苯并[l]菲(4), 再与甲醛进行羟醛缩合, 制成了2,6,10-三-(4-羟基-3,3,5,5-四羟甲基环己烷基)-1,2,3,4,5,6,7,8,9,10,11,12-十二氢苯并[l]菲(5), 将5与过量的3反应, 得到了目标树形大分子化合物2,6,10-三-{15-(3,11-二(-4-(3-((9-(4-二氰基乙烯基)苯基)2,4,8,10-四氧杂螺[5.5]十一烷基)))-7-羟基-二螺[5.1.5.3]十六烷基)}-1,2,3,4,5,6,7,8,9,10,11,12-十二氢苯并[l]菲(6), 收率为18.1%. 产品结构经IR, 1H NMR, MS和元素分析进行了表征. 对影响反应的因素进行讨论.     

1,3,2-氧氮磷杂环戊烷衍生物(Ⅱ)——2-二乙氨基-3-取代甲酰基-1,3,2-氧氮磷杂环戊烷衍生物的合成及其性质研究

用六乙基亚磷酰胺与N-(β-羟基乙基)取代甲酰胺进行成环反应,合成了一系列新的有机磷杂环化合物,2-二乙氨基-3-取代甲酰基-1,3,2-氧氮磷杂环戊烷,然后与硫作用生成2-硫逐代衍生物,亦可不经分离一步完成上述反应。     

cis-3-芳脲基-2-苯基-2-氧代萘并[1,2-d]-1,2-氧膦杂环戊烷合成

利用2-羟基-1-萘甲醛、芳基脲、苯基二氯化膦作为起始原料,在无水甲苯中反应合成cis-3-芳脲基-2-苯基-2-氧代萘并[1,2-d]-1,2-氧膦杂环戊烷.产物结构经IR,1HNMR,31PNMR和元素分析等进行了表征.     

螺[二苯并[a,j]氧杂蒽-14,9’-芴]的合成及性质简

芴酮与2-萘酚在硫酸和3-巯基丙酸的作用下反应得到化合物螺[二苯并[a,j]氧杂蒽-14,9’-芴]. 采用核磁共振、质谱、红外光谱和元素分析等对该化合物进行了表征,并通过X射线衍射法测得了其晶体结构,确定该化合物是通过二苯并[a,j]氧杂蒽中的含氧六元杂环和芴中的五元环共用一个碳原子形成一个螺环. 利用荧光光谱和热分析等手段对该化合物的性质进行了研究,结果表明其最大荧光发射峰为366 nm,熔点为297 ℃,热分解温度为329 ℃,具有较高的热稳定性.     

螺[二苯并[a,j]氧杂蒽-14,9'-芴]的合成及性质

芴酮与2-萘酚在硫酸和3-巯基丙酸的作用下反应得到化合物螺[二苯并[a,j]氧杂蒽-14,9'-芴]. 采用核磁共振、 质谱、 红外光谱和元素分析等对该化合物进行了表征, 并通过X射线衍射法测得了其晶体结构, 确定该化合物是通过二苯并[a,j]氧杂蒽中的含氧六元杂环和芴中的五元环共用一个碳原子形成一个螺环. 利用荧光光谱和热分析等手段对该化合物的性质进行了研究, 结果表明其最大荧光发射峰为366 nm, 熔点为297 ℃, 热分解温度为329 ℃, 具有较高的热稳定性.     

3-仲氨基氧杂环丁烷-3-腈衍生物的合成

以仲胺、氧杂环丁-3-酮和三甲基氰硅烷为原料,无水甲醇为溶剂,无需催化剂,一步反应合成目标化合物3-仲氨基氧杂环丁烷-3-腈衍生物(1a～1d),产物结构经¹H NMR、¹³C NMR和ESI-MS表征。并以异吲哚啉、氧杂环丁-3-酮和三甲基氰硅烷的反应为模型反应,考察影响产物1a收率的主要因素,优化反应条件为:物料摩尔比为n(异吲哚啉)∶n(氧杂环丁-3-酮)∶n(三甲基氰硅烷)=2.0∶1∶2.5;反应溶剂为无水甲醇,在65℃反应6h,在此反应条件下,化合物1a收率78.3%。化合物1a与苯基溴化镁在四氢呋喃中室温反应5h,可得到2-(3-苯基氧杂环丁烷-3-基)异吲哚啉(4)和[3-(异吲哚啉-2-基)氧杂环丁烷-3-基](苯基)甲酮(5),收率分别为40.1%和31.5%。     

含磺化芴基侧基的聚芳醚氧膦质子交换膜的合成与表征

将9,9-二(4-羟苯基)芴(BHPF)与二(4-氟苯基)苯基氧膦(BFPPO)聚合,合成了含芴基侧基的聚芳醚氧膦(PAEPO),并采用后磺化法,制备了侧链型磺化聚芳醚氧膦(sPAEPO)质子交换膜.通过核磁与红外确定了聚合物的化学结构,用原子力显微镜对sPAEPO的微观结构进行了表征,同时对sPAEPO质子交换膜的尺...     

5-氢-1,4,6,9-四氧-5-膦螺环[4.4]壬烷的制备及其硅烷基化反应

5-氢-1,4,6,9-四氧-5-膦螺环[4.4]壬烷2是合成有机磷阻燃剂的重要原料.其合成方法虽有一些报道,但尚未见2-氯-1,3,2-二氧膦杂环戊烷1与乙二醇反应的合成路线.我们用1、乙二醇及三乙胺以等摩尔比反应,发现2的收率很低,主要得到环状二亚磷酸酯3,将3再与乙二醇反应,很容易转化成2,反应式如下:     

Pyrolysis Process of Plant Fibers北大核心CSCD

The natural plant fiber has a large molecular weight and complex structure and composition,and its thermal cracking products and the composition distribution are also more complex. The fast pyrolysiscomprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry（Py-GC×GC-TOF/MS）,thermogravimetry-Fourier transform infrared spectroscopy（TG-FT-IR）,and in situ Fourier transform infrared spectroscopy（in situ FT-IR）methods were used to study the thermal pyrolysis process of six different natural fibers. The distribution of thermal pyrolysis products of different fibers under different pyrolysis temperatures was investigated and the product form was fully discussed. The research results show that the products of fiber pyrolysis mainly include alcohols,aldehydes,ketones,acids,esters,hydrocarbons, dehydrated sugars and CO2,etc. The types of pyrolysis products of different natural plant fibers are obviously different,and the main product types obtained are all different. At the same time,the results of in situ infrared spectroscopy and mass spectrometry show that pyrolysis products are closely related to the pyrolysis temperature. The results of in situ infrared experiments show that when the pyrolysis temperature is lower than 100 °C,the adsorbed water on the surface of the fiber structure is desorbed,but the fiber structure does not change significantly. When the pyrolysis temperature range is 100~200 °C,the temperature has little effect toward the pyrolysis process. When the temperature exceeds 300 °C,the fiber pyrolysis reaction intensifies and the surface structure changes significantly,and the main products are aldehydes and ketones. © 2022, Science Press (China). All rights reserved.     

十二烷基硫酸钠对原位晶化制备小晶粒NaY的影响

研究了十二烷基硫酸钠对原位晶化制备小晶粒NaY的影响,并以包含小晶粒NaY的原位晶化产物为母体,通过铵交换和稀土离子交换制备出了REUSY催化剂.采用X射线衍射(XRD)、扫描电镜(SEM)、X射线荧光(XRF)及N₂物理吸附-脱附等手段对样品进行了表征,采用微反活性评价装置和小型固定流化床(ACE)评价了所制备催化剂在重油催化裂化反应中的催化性能.结果表明:在原位晶化合成NaY的体系中,添加高岭土微球质量5%的十二烷基硫酸钠,可以将分子筛的平均晶粒尺寸由540 nm减小到250 nm.相比于常规的原位晶化型流化催化裂化(FCC)催化剂,以包含小晶粒NaY的原位晶化产物为母体所制备出的催化剂,在反应原料的转化率、裂化产物的选择性以及抗积碳性能等方面均有明显的提高或改善.     

电解水催化材料动态构效关系的原位拉曼研究进展北大核心CSCD

可再生能源电解水产氢对于实现碳中和目标和未来可持续社会的发展具有重要意义。然而,在电解水服役过程中,催化材料往往会发生复杂的结构演变,这对深入理解电解水催化材料反应机制和精准设计高效催化材料造成了挑战。原位电化学拉曼表征技术对催化材料结构动态演变过程的实时监测,是揭示电解水材料动态构效关系,解析催化反应机理的关键。本文介绍了原位电化学拉曼表征技术的基本原理,重点综述了其在催化材料相结构演变、表面活性位点和界面水分子行为中的最新进展,阐述了电解水催化材料在服役过程中结构演变与性能演变之间的变化规律,为实现催化材料全生命周期动态构效关系的精准构建提供了技术基础。最后,分析总结了原位电化学拉曼表征技术在电解水应用过程中存在的问题与挑战,并对先进原位电化学拉曼技术未来的发展进行了展望。     

On-probe pyrolysis desorption electrospray ionization (DESI) mass spectrometry for the analysis of non-volatile pyrolysis products

An on-probe pyrolyzer has been constructed and interfaced with desorption electrospray ionization (DESI) mass spectrometry (MS) for the rapid analysis of non-volatile pyrolysis products. The detection and analysis of non-volatile pyrolysis products of peptides, proteins and the synthetic polymer poly(ethylene glycol) were demonstrated with this instrument. The on-probe pyrolyzer can be operated off-line or on-line with the DESI source and was interfaced with a tandem MS (MS/MS) instrument, which allowed for structure characterization of the non-volatile pyrolytic products. Advantages of this system are its simplicity and speed of analysis since the pyrolysis is performed in situ on the DESI source probe and hence, it avoids extraction steps and/or the use of matrices (e.g., as in MALDI–MS analyses).     

In situ polymerized poly(butylene succinate)/silica nanocomposites: Physical properties and biodegradation

A series of poly(butylene succinate)/silica (PBS/silica) nanocomposites were prepared by in situ polymerization. Solid-state ²⁹Si NMR and FTIR analysis indicated that silanol-bonded carbonyl groups are established within PBS/silica nanocomposite materials. Rheological effects inherent to the silica filler were evaluated by melt rheological analysis as a function of shear force in the molten state. Despite high shear force, PBS/silica nanocomposites maintained a relatively high melt viscosity, attributable to a network structure resulting from covalent bonding between silica and the polymer chain. Nanocomposite material containing 3.5 wt% silica exhibited greatly improved mechanical properties. The tensile strength at break and elongation were ca. 38.6 MPa and 515%, while those of the parent PBS were 26.3 MPa and 96%, respectively. PBS/silica nanocomposites showed composition dependency on biodegradation ascribable to reduced crystallinity and preferential microbial attack.     

可充电池的磁共振研究

快速增长的对安全能源的需求,促使科研工作者不断探索高能量密度的可充锂离子电池(LIBs)。发展原位表征技术能更好地研究电池工作中的锂离子镶嵌机制和电池失效因素。固体核磁共振(NMR)能有效的测试短程化学环境:通过对~1H、~(6,7)Li、~(11)B、~(13)C、~(17)O、~(19)F、~(23)Na和~(31)P等同位素来探测电池材料的微观结构。除了魔角旋转(MAS)高分辨NMR谱图研究电池材料的精细结构之外,核磁共振还能无损地捕获、研究电池材料在充放电循环中的演化。因此,原位核磁共振NMR及成像(MRI)可拓展到电池充放电循环中的锂离子的动态演化以及锂离子浓度的时空分布信息。互为补充地,电子顺磁共振(EPR)及成像(EPRI)能有效地跟踪和捕获电极过渡金属、阴氧离子(O_2~(n-))的氧化还原过程。这些实时捕获的动态信息能更好地指导电极材料的构效、微观设计和电池组装的改进,最终获得优异的电化学性能。     

环己烯对噻吩在CuY分子筛上吸附的影响机制

A CuY zeolite prepared by liquid phase ion exchange was characterized by X-ray photoelectron spectroscopy, pyridine in situ Fourier transform infrared (in situ FTIR) spectroscopy, and ammonia temperature programmed desorption. The effect of cyclohexene on the adsorption of thiophene over the prepared CuY zeolite was explored by in situ FTIR. In particular, the role of the zeolite's Br?nsted acidity was investigated in the adsorption process. The results show that the percentage of Cu⁺ on the surface of the CuY zeolite can reach 77%. The surface acidity of the CuY zeolite mainly comprises medium and strong Br?nsted acidity and Lewis acidity. According to the adsorption results, cyclohexene negatively influences thiophene adsorption on the Br?nsted or Lewis acid sites in CuY by competitive adsorption. Although polymerization of thiophene and cyclohexene can occur easily on the HY or REY zeolites, the presence of Br?nsted acids in the CuY zeolite was not sufficient to polymerize either thiophene or cyclohexene. This difference may be caused by an anti-synergistic effect between the Cu ions of the CuY zeolite and neighboring Br?nsted acid sites, the result of which inhibits the polymerization of adsorbed thiophene and cyclohexene.     

Copper-sulfide cluster assembled architecture via in situ reaction

A new copper-thiolate cluster assembled framework [Cu₂(μ₄-SCH₃)Cl]_n (1), has been solvothermally synthesized through in situ reaction viz., in situ ligand generation and metal reduction. Compound 1 represents the first 3D framework based on Atlas-sphere functionalized by single μ₂-Cl^- groups. DOS calculation reveals the interaction of electronic structures. It is found that the HOMO is mainly distributed on Cl, Cu and S bonding orbitals, while the LUMO is dominated by Cu-Cl antibonding orbitals.     

Role of additives in wood–polymer composites. Relationship to analogous radiation grafting and curing processes

Wood polymer composites (WPC) were prepared by impregnating an Australian softwood, Pinus radiata with methyl methacrylate which subsequently underwent in situ polymerisation utilising either γ radiation or the catalyst–accelerator method. Novel additives including thermal initiator, crosslinking agents, an inclusion compound and oxygen scavenger were incorporated to improve the polymer loading and properties of the resulting WPC. Polymer loadings of WPC obtained utilising the accelerator–catalyst method corresponded well with those obtained using γ radiation with 20 kGy radiation dose. The mechanistic significance of the current work in analogous radiation grafting and curing processes is discussed.     

Anisotropy of non-mesogenic polymer networks dispersed in a liquid crystal matrix

We report here original results characterizing in situ the interactions between a smectic liquid crystal phase and a polymer network dispersed in it. These results have been obtained by neutron scattering on smectic liquid crystal (8CB) samples containing a physical network of 1.5wt% polymer. The samples were polymerized in the isotropic, or in the smectic A phases. For the first time it is experimentally proved that the polymerization of non-mesogenic monomers in an aligned smectic A matrix induces anisotropy in the resulting network. The network becomes elongated along the liquid crystal director. When the polymerization is carried out in the isotropic phase the polymer network has an isotropic distribution even if a magnetic field, which orients the liquid crystal director, is later applied. On the other hand, studies show that after several thermal cycles, the liquid crystal orientational order still remained. Without other external constraints, the polymer network freezes the alignment of the liquid crystal. It is probably imposed by pendant reticulates on the diffuse liquid crystal-polymer interfaces.