固相萃取-衍生化-气相色谱/质谱测定水中类固醇类环境内分泌干扰物

建立了固相萃取-衍生化-气相色谱/质谱联用同时测定水中4种类固醇类环境内分泌干扰物雌酮(E1)、17β-雌二醇(E2)、17α-乙炔基雌二醇(EE2)、雌三醇(E3)的分析方法.通过对比衍生化试剂 N,O-双三甲基硅基三氟乙酰胺(BSTFA)和N-甲基-N-三甲基硅基三氟乙酰胺(MSTFA)的衍生化条件及效果,解释了文...     

固相萃取-气相色谱-质谱法测定酱油中3-氯-1,2-丙二醇

建立了酱油中3-氯-1,2-丙二醇(3-MCPD)残留量的同相萃取-气相色谱-质谱(GC/MS)分析方法.利用SampliQ OPT固相萃取柱净化样品,考察了乙醇、丙酮、乙醚、乙醚-正已烷(9:1,V/V)4种洗脱液对3-MCPD回收效果的影响.洗脱液在室温下经氮气吹干后用双(三甲基硅烷基)三氟乙酰胺-三甲基氯硅烷(B...     

全氟和多氟烷基磺酸的研究 Ⅷ、N-(3′-三氯硅基丙基)-3-氧杂全氟烷基磺酰胺及其衍生物的合成

长链含氟烷基三氯硅烷及其衍生物的合成和性质已有不少报道,本文报道一类新的含氟磺酰胺基取代的硅烷衍生物的合成.这类化合物可作为无机硅酸盐材料的表面处理剂,由于含氟基团的引入,使被处理的物质具有氟碳表面的一些特性. 3-氧杂全氟烷基磺酰氟(1)和烯丙胺在三氟三氯乙烷(FC-113)中反应,得到对应的N-烯丙基取代的磺酰胺2;2与甲醇钠-碘甲烷反应,得到N-甲基-N-烯丙基取代的磺酰胺3.2和3分别与三氯硅烷在氯铂酸催化下反应,得到含氟磺酰胺基取代的三氯硅烷4     

以2,2,5,5-四氟-2,5-二氢呋喃桥连的1,2-二噻吩乙烯类光致变色分子的合成

设计并合成了新型的以2,2,5,5-四氟-2,5-二氢呋喃桥连的1,2-二噻吩乙烯类光致变色分子1,从廉价易得的六氯丁二烯出发,经醇解、氯化、关环和氟化反应合成了关键中间体全氟2,5-二氢呋喃(2),并通过与化合物3'-溴-[2,2':5',2']三噻吩(3)的偶合反应得到含氟光致变色分子1.     

含氟芳杂环化合物的合成II: 3,5-二硝基-4-氯三氟甲苯和3,5-二硝基-2-氯三氟甲苯与含氮亲核试剂的反应

本文报道了3,5-二硝基-4-氯代苯并三氟化物和3,5-二硝基-2-氯代苯并三氟化物与含氯亲核试剂的反应, 并用于合成诸如5,10-二氢-1-硝基-3-三氟甲基吩嗪和2-(O-氟代苯基)-4-硝基-6-三氟甲基苯并咪唑等含氟芳香族和杂环化合物, 讨论了反应条件对产品生成的影响.     

LiPF_6/三氟乙酰胺室温熔盐的制备及在碳-碳电容器中的性能

利用LiPF6和三氟乙酰胺为前驱物,制备了低共熔温度约为-62℃的室温熔盐,并测试了该熔盐作为碳-碳电化学电容器(EDLCs)电解液时的性能。其中,使用差示扫描量热法(DSC)和红外光谱法(FTIR)分析了不同LiPF6和三氟乙酰胺配比熔盐的热稳定性,拟制了该二元组分的共熔相图,认为LiPF6和三氟乙酰胺极性基团间的氢键作用促成了室温熔盐的形成。循环伏安(CV)、交流阻抗(EIS)和电导等测定结果表明,所制备的LiPF6/三氟乙酰胺电解液的室温电导率为1.30mS/cm,电化学窗口大于5.6V,大于60℃的使用温度,作为电解液可满足碳-碳EDLCs的使用要求。     

气相色谱-质谱联用技术用于尿样中β-阻断剂的初筛定量和确证

建立了一种同时测定5种β-阻断剂(卡替洛尔、艾司洛尔、普萘洛尔、索他洛尔、比索洛尔)的气相色谱-质谱方法(GC-MS),并用于疑似阳性实际尿样的初筛、定量和确证。分别对游离态和结合态药物进行了提取,合并提取液后采用N-甲基-N-三甲基硅基-三氟乙酰胺(C6H12F3NOSi, MSTFA)和N-甲基-双三氟乙酰胺试剂(C5H3F6NO2, MBTFA)进行混合衍生。确定了优化的GC-MS条件,建立了采用选择离子监测方式（SIM）初筛和全扫描方式（SCAN）确证的实验流程;建立了SIM模式下5种β-阻断剂的尿样加标工作曲线,其SIM方法的检出限达0.2～1.0 ng/mL,尿样的加标回收率为70.5%～103.4%,相对标准偏差小于14.9%。该方法成功地用于普萘洛尔阳性尿样的检测,并绘制了普萘洛尔的尿代谢曲线。该方法对兴奋剂检测中β-阻断剂滥用的控制有重要的意义。     

α-[4-(N,N-二甲基)苯基]-α-三氟甲基-α-炔丙胺的不对称合成

以N,N-二甲基对溴苯胺为起始原料,利用含氟砌块法,经3步反应合成了α-[4-(N,N-二甲基)苯基]-α-三氟甲基-α-炔丙胺,其结构经1H NMR,13C NMR,19F NMR,IR,MS和HR-MS确证。     

N-(1,2,4-三唑)含氟肉桂醛亚胺的合成及生物活性

含氟肉桂醛与4-氨基-5-(3,4,5-三甲氧基苯基)-1,2,4-三唑-3-硫酮(2)缩合生成5-(3,4,5-三甲氧基苯基)-4-取代苯基烯丙亚胺基-1,2,4-三唑-3-硫酮(3),再烷基化为新型含氟肉桂醛1,2,4-三唑亚胺(4).化合物结构经1HNMR,13CNMR,IR以及元素分析确认,并用X-ray单晶衍射测定了化合物4g的晶体结构,证实了分子中两个环外双键N=C和C=C均为E-式构型.初步生物活性测试结果表明,部分化合物具有抗植物病毒活性.     

α′-三氟甲基含氟β-二酮的合成

为了合成手性含氟β-二酮顺磁性镧系螯合物作为~1H NMR手性位移试剂,我们曾试图用2-三氟甲基-3-氧杂八氟己酸乙酯与3,3-二甲基-2-丁酮(1)在乙醇钠存在下进行Claisen酯缩合反应合成β-二酮,结果只发生氟仿型反应,生成碳酸二乙酯.若用三氟乙酸乙酯与1,I,1-三氢_3,6-二(三氟甲基)-4,7-二氧杂-2-十一氟癸酮在乙醇钠存在下反应,也得到氟仿型反应产物2-氢-5-三氟甲基-3,6-二氧杂-十四氟壬烷(2).本文采用碱性较弱的     

Theoretical study of the features of the nuclear-chemical synthesis of phenyl-substituted picoline derivatives

Sections of potential energy surfaces (PES) of phenyl cation addition to picolines were constructed using the DFT/B3LYP and MRCI methods. In the framework of the SA-MCSCF method energies of excited states of the products and intermediates in the reaction of phenyl cation with 4-picoline were determined. The equilibrium geometry and the dissociation energy of intermolecular complexes of benzene and picolines were calculated by the DFT/B3LYP method. The experimentally observed decrease in the yield in the reaction of phenyl cation addition to the 4-picoline as compared with 2- and 3-picolines was substantiated.     

葡聚糖分子对氢氧化铁矿化结晶的调制作用

通过对比五种不同葡聚糖浓度的Fe3＋/葡聚糖矿化作用体系中Fe(OH)3凝胶在早期矿化阶段的成核和相变过程来研究葡聚糖对铁矿物的结晶与转化的调控作用. 运用ICP-AES(等离子发射光谱仪)观察各个矿化体系中上清液的[Fe3＋]浓度及相应pH的变化, 矿化产物运用FTIR、XRD进行表征. 结果发现, 上清液中[Fe3＋]经历了两次下降过程, 在陈化的第三天突然回增. 与不含葡聚糖的矿化作用体系很快形成结晶良好的α-FeOOH不同, 在含有葡聚糖的矿化作用体系中最初形成的物相主要为β-FeOOH. 葡聚糖分子通过与Fe3＋配位吸附在铁氧化物颗粒的表面促进了β-FeOOH转化为α-Fe2O3. 相变是经过溶解-再结晶机制进行的. [Fe3＋]第二次下降正是由于β-FeOOH转化为α-Fe2O3引起的. 葡聚糖浓度适当增大, β-FeOOH溶解加快, 有利于相变的进行. 因此葡聚糖的存在能显著影响在氢氧化铁凝胶中形成晶核的结构类型及其相变历程.     

Functionalization of the methylene bridges of the calix[6]arene scaffold

The bromine atoms of the hexabromo calixarene derivative 3 were replaced by other groups under S(N)1 conditions, allowing the facile synthesis of calix[6]arene derivatives incorporating identical functionalities at all bridges. Heating at reflux a mixture of 3 and the appropriate alcohol incorporated primary and secondary alkoxy substituents. Hydride abstraction was observed when the reaction with EtOH and i-PrOH was conducted in hexafluoroisopropanol (HFIP). Solvolysis of 3 in TFE in the presence of strong nucleophiles (such as N3(-) and aniline) afforded the corresponding hexaazido and hexaanilino derivatives. Hydroxyl groups were incorporated into the calix[6]arene scaffold via acetolysis of 3, followed by LiAlH4 reduction of the hexaacetate derivative obtained. Friedel-Crafts alkylations in the absence of Lewis acids were conducted by heating at reflux a mixture of 3, HFIP, and a substituted benzene derivative (e.g, m-xylene, p-methyl anisole, mesitylene). The calix[6]arene bridges were alkylated by heating at reflux a mixture of 3 and 2,4-pentanedione in TFE or HFIP. In all cases the reaction proceeded with high diastereoselectivity, and the major isomer isolated was assigned to the rc5 (i.e., all-cis) form. NMR spectroscopy indicates that the conformation adopted by the macrocycle possesses 3-fold symmetry (a "pinched cone") that is rigid in the laboratory time scale in the mesityl-substituted derivative.     

A theoretical analysis of the coordination modes of CuII with penicillins: activation of the beta-lactam C-N bond.

The interaction of CuII with 6-formylamino-3alpha-carboxypenam and 6-acetylamino-3alpha-carboxypenam was investigated by means of DFT calculations with the UB3LYP functional. Nine different modes of complexation between CuII and 6-formylamino-3alpha-carboxypenam were located. When two water molecules directly bonded to CuII are included in the calculations on 6-acetylamino-3alpha-carboxypenam as penicillin model, only six CuII(H2O)2-6-acetylamino-3alpha-carboxypenam complexes (1S-6S) are found. In solution the four most stable complexes obtained from our calculations, 6S, 1S, 2S, and 3S, exhibit CuII in square-planar coordination with at least one bond to the carboxylate group, in agreement with experimental evidence. Complexes 6S, 1S, and 3S were previously suggested by available experimental evidence. In three of the most stable complexes (6S, 2S, and 3S) the beta-lactam C-N bond is remarkably activated and displays C-N bond lengths similar to those found in some tetrahedral intermediates located for the hydrolysis of 2-azetidinones. This suggests that these kinds of complexes belong to the reaction coordinate for the degradation of beta-lactam antibiotics in the presence of CuII.     

A major urinary protein of the domestic cat regulates the production of felinine, a putative pheromone precursor

Domestic cats spray urine with species-specific odor for territorial marking. Felinine (2-amino-7-hydroxy-5,5-dimethyl-4-thiaheptanoic acid), a putative pheromone precursor, is excreted in cat urine. Here, we report that cauxin, a carboxylesterase excreted as a major urinary component, regulates felinine production. In vitro enzyme assays indicated that cauxin hydrolyzed the felinine precursor 3-methylbutanol-cysteinylglycine to felinine and glycine. Cauxin and felinine were excreted age dependently after 3 months of age. The age-dependent increases in cauxin and felinine excretion were significantly correlated. In mature cats, cauxin and felinine levels were sex-dependently correlated and were higher in males than in females. In headspace gas of cat urine, 3-mercapto-3-methyl-1-butanol, 3-mercapto-3-methylbutyl formate, 3-methyl-3-methylthio-1-butanol, and 3-methyl-3-(2-methyldisulfanyl)-1-butanol were identified as candidates for felinine derivatives. These findings demonstrate that cauxin-dependent felinine production is a cat-specific metabolic pathway, and they provide information for the biosynthetic mechanisms of species-specific molecules in mammals.     

19F NMR investigation of the polarities of the metal-oxygen bonds and the electronegativities of the Ph n M groups in organometallic derivatives of tris(4-fluorophenyi)stannanol

A number of Ar₃MOM*Ph₃ compounds containing Group lVB metals were synthesized or generated in solution. On the basis of¹⁹F NMR data for (4-FC₆H₄)₃SnOMPh₃ compounds, the relative polarities of the M-O bonds and relative electronegativities of the Ph₃M groups were evaluated and the latter values were found to correlate with the electronegativities of the central metal atoms. The variation of the shielding of the heavy nuclei in Ph₃SnOMPh₃ and Ph₃PbOMPh₃ does not reflect the variation in the electron density on the tin and lead atoms.     

Molecular dynamics simulation studies of the influence of imidazolium structure on the properties of imidazolium/azide ionic liquids

Atomistic molecular dynamics simulations were performed on 1-butyl-3-methyl-imidazolium azide [bmim][N(3)], 1-butyl-2,3-dimethylimidazolium azide [bmmim][N(3)], and 1-butynyl-3-methyl-imidazolium azide [bumim][N(3)] ionic liquids. The many-body polarizable APPLE&P force field was augmented with parameters for the azide anion and the bumim cation. Good agreement between the experimentally determined and simulated crystal structure of [bumim][N(3)] as well as the liquid-state density and ionic conductivity of [bmmim][N(3)] were found. Methylation of bmim (yielding bmmim) resulted in dramatic changes in ion structuring in the liquid and slowing of ion motion. Conversely, replacing the butyl group of bmim with the smaller 2-butynyl group resulted in an increase of ion dynamics.     

Thermochemical properties of the gaseous bromo-iodides of Dy and of the Na-Dy tetrahalo complexes

The gaseous mixed dimers NaDyBr4 and NaDyI4 and the bromo-iodide species DyBrI, DyBr2I, DyBrI2, NaDyBr3I, NaDyBr2I2, and NaDyBrI3 were generated in an effusion cell reactor at elevated temperatures using several different source configurations and were identified by mass spectrometry. A number of gaseous equilibria involving these species were studied, and thermochemical properties were derived with the aid of thermal functions based on estimated molecular constants. Enthalpies of formation of NaDyBr4 and NaDyI4 are compared with values in the literature, while results for the bromo-iodides are in close accord with values interpolated from data on the pure metal bromides and iodides.     

烯胺酮与烯胺酯的交叉缩合反应及自缩合反应的区域选择性研究

烯胺酮与烯胺酯以(3C+3C)缩合反应形成多取代芳环化合物,具有区域选择性。用波谱和 X-射线衍射技术确定了产物的结构,讨论了反应机理。     

萘并呋喃类化合物的染料化光氧化及其杂环衍生物的合成与表征

萘并呋喃类化合物1、7在四苯基卟啉存在与氧低温反应给出相应的二氧杂环丁烷类产物2、8，室温下分别全部分解成乙酰基乙酰氧基化合物4、9。2和盐酸作用可给出呋喃3-位甲基及所在萘半环β位的二氯代产物6。4与盐酸反应通过失去萘α位的酰基，形成羟基呋喃化合物3，1在三溴化硼酸解下亦可得同一产物。4在醋酸钠/酸酐中环构生成3-乙酰基吡喃酮(5)。