四溴汞(Ⅱ)酸钾-异辛基苯二聚乙二醇醚二甲基苄基氯化铵的共振散射光谱及其分析应用

在pH2～8的溶液中,四溴汞（Ⅱ）酸钾和异辛基苯二聚乙二醇醚二甲基苄基氯化铵（BTC）反应生成离子缔合物,在390nm处有一共振散射峰,峰强度随汞（Ⅱ）质量浓度的增加而增大,据此建立了测定痕量汞的新方法。在实验条件下,此法测定汞（Ⅱ）的线性范围是14～240μg/L,检出限为μg/L,已用于合成水样和环境水样中汞（Ⅱ）的测定。     

合成硅氧醚的新方法：Silyltriflimides与醇或与醚反应

首次利用silyltriflimides［双－（三氟甲磺酰）－亚胺基硅烷］与醇或醚反应合成了一系列非环链状或环状的硅氧醚,反应产率较好。其中反应物silyl triflimides很容易由相应的苯基硅烷或丙烯基硅烷与HNTf2通过质子脱硅化反应得到。合成的新化合物的结构用1H NMR, 13C NMR, MS, IR 和HRMS等进行了表征.     

两种七氟醚自由基[(CF3)2C(·)OCH2F,(CF3)2CHOC(·)HF]与氧气反应及OH·再生机理的理论研究

温室气体七氟醚氧化降解可以产生两种反应活性截然不同的自由基，即（CF₃）₂C（·）OCH₂F与（CF₃）₂CHOC（·）HF.采用M06-2X/6-311++G（d，p）与CBS-Q理论方法研究了两种七氟醚自由基与氧气（O₂）反应的机理.与普通的烷基自由基+O₂的无垒复合反应不同，多氟取代的七氟醚自由基与O₂反应需经过1.3~1.8 kcal·mol^-1的势垒才能生成过氧自由基中间体RO₂·.虽然O₂更易于加成到富氟的自由基位点，但与贫氟自由基位点结合生成RO₂·放热更多，且随后的六中心氢迁移生成QOOH中间体需要克服更高的势垒.QOOH分解包括三种主要的OH·再生途径，即：分步解离、三体同步解离、四中心分子内S_N2反应.对于（CF₃）₂C（OC（·）HF）OOH，三条途径互为竞争；对于（CF₃）₂C（·）OC（HF）（OOH），分子内S_N2反应为OH·再生的主要途径，分步或三体同步解离则为次要机理.研究为阐明多氟取代基对大气中OH·循环的影响规律提供了理论依据.     

光响应偶氮苯基长链小分子功能化聚乙烯醇的合成与性能

以对甲氧基苯胺为起始原料，经重氮化、亲电加成、取代成醚和酰氯化系列反应制得具有连续柔性亚甲基（五个）的偶氮苯长链小分子（3）；再通过酯化反应将3接枝到聚乙烯醇（PVA）分子链上，合成了具有光响应行为的偶氮苯基长链小分子功能化聚乙烯醇（4），其结构经FT IR表征。并对4进行了UV-Vis、 DSC和 TG分析。结果表明：经偶氮苯化合物功能化PVA的最大分解峰推迟了120 ℃，热稳定性显著提高；分别经过30 s和3 min的紫外光和可见光照射后，偶氮苯官能团发生顺反异构转化，表明功能化PVA具有可逆光致异构化行为。     

钼－氯酸钾－盐酸苯肼－变色酸催化光度法测定食品中痕量钼

本文利用钼（Ⅵ）催化氯酸钾氧化盐醚苯肼与变色酸试剂显色的反应测定痕量钼，最大吸收峰位于５０６ｎｍ，线性范围０．００５～０．１μｇ／２５ｍＬＭｏ（Ⅵ），操作简便，选择性好，可不经分离测定食品中痕量钼。加标准回收率为９８％～１０５％。与其他方法对照，相对偏差＜５％。     

基质辅助激光解吸电离—飞行时间质谱表征6氟双酚A芳香环状聚醚酮（砜）

应用基质辅助激光解吸电离飞行时间质谱,在不同阳离子剂的存在下,对６氟双酚Ａ聚芳醚酮（砜）环状低聚物的结构进行了确认,研究了环状化合物对金属离子的选择性及激光质谱表征含氟环状低聚物的适宜条件。     

二乙基锌促进CO2的硅氢化反应以及CO2为C1合成子的有机胺甲酰化或脲化反应

CO₂的固定和转化具有重要研究意义,特别是采用廉价且良好生物相容性的金属催化剂将其转化为有用的有机化合物.本工作报道采用商品化ZnEt₂（1.0 mol%）可促进CO₂的硅氢化反应生成甲氧基硅醚,以及CO₂为C1合成子的有机胺甲酰化或脲化反应生成酰胺或脲类化合物.在1.0 mol% ZnEt₂存在下,CO₂和（EtO）₃SiH发生硅氢化反应,一锅选择性还原为甲氧基硅醚（CH₃OSi（OEt）₃）.考察了反应条件的影响,在1.0 MPa CO₂起始压力下,90℃反应7 h,甲氧基硅醚的产率达到约90%.当上述反应体系中存在有机胺时,则发生了CO₂为C1合成子的的有机胺甲酰化或脲化反应.当采用二级有机胺为底物时,反应生成酰胺类产物;当一级有机胺为底物时,反应主要生成脲类产物.考察了反应底物取代基的影响,含脂肪基和芳香基的二级有机胺均可发生甲酰化反应,芳香基的对位含给电子取代基时明显有利于该甲酰化反应.含脂肪基和芳香基的一级有机胺均可发生脲化反应,芳香基对位取代基的电子性质对脲化反应的影响规律不如在甲酰化反应中的明显.     

Ir(III)螯合物催化醚的硅氢化反应中负氢来源的机理研究

采用DFT方法对Ir（Ⅲ）螯合物催化乙醚硅氢化生成乙烷和乙基硅醚的反应展开理论研究.反应中[H-Ir-H]，[H-Ir-Si]，[Ir（HSiEt₃）]和[Et₃Si-Ir-（H）₃]化合物均为可能的负氢来源.理论研究表明[H-Ir-H]化合物是最优势的负氢来源.通过扭曲-相互作用能分析，发现其他三种可能的负氢来源不优势的原因在于HSiEt₃或SiEt₃基团对铱中心的络合.更为重要的，我们发现[H-Ir-H]化合物中适中的Ir-H键解离能，小位阻以及SiEt₃对醚的络合而产生的促进作用共同使得[H-Ir-H]化合物上的负氢转移相对优势.     

采用Pd／树脂催化剂的轻汽油临氢醚化反应研究

研究了催化裂化轻汽油临氢醚化工艺,以降低催化裂化汽油的烯烃含量并提高辛烷值,制备了Pd负载D005阳离子交换树脂催化剂,该催化剂具有同时催化二烯烃选择性加氢和步碳烃与甲醇醚化的功能。考察了遗金属负载量和反应择醚收率的影响,在反应温度343K、压力1．5Mpa,n（甲醇）/ n(叔碳烯烃）比＝1．1、n（氢）／n（二烯）比＝2、液时空速3/h的条件下,醚收率达55．32％。2016h的寿命试验表明,该催化剂活性稳定,可以长周期使用。     

人工雌激素己烯雌酚酶联免疫分析方法的建立

本实验旨在初步建立人工合成雌激素己烯雌酚（DES）的酶联免疫吸附分析（icELISA）方法。实验首先合成了己烯雌酚的两种半抗原正丁酸己烯雌酚单醚（DES-CP）、乙酸己烯雌酚单醚（DES-CME）。DES-CP与牛血清蛋白（BSA）偶联作为免疫原免疫BALB/c雌性小鼠并进一步制备了DES单克隆抗体，表征了单克隆抗体的亲和力和特异性。在ELISA优化的条件下，方法的抑制中浓度为 IC₅₀＝9.8 ng/mL，检测限 IC₂₀＝2.3 ng/mL，工作浓度范围为 2-42 ng/mL. 抗体与己烷雌酚、双烯雌酚的交叉反应分别为 44%, 27%，与天然雌激素雌二醇的交叉反应小于0.1%. 评估了分析缓冲液中盐离子浓度、pH、有机溶剂含量等因素对分析方法的影响。本分析方法应用于水样的添加实验，回收率符合分析精度要求。HPLC法对实验结果进行了确证，证明了ELISA应用于水样分析的可靠性。     

NMR assignments of a di-pentacyclo-undecane cyclic ether

The X-ray structure of a di-pentacyclo-undecane cyclic ether was recently reported. As part of a programme to use NMR spectroscopy for the structure elucidation of cage compounds, the complete NMR assignments of the cyclic ether was attempted. Major overlap of proton and carbon signals of the two cages is observed. It was required to elucidate the fragment analogues that represent similar structural features of the cyclic ether in order to get an approximate but reasonable insight into the complex overlapping signals. Normal 2D NMR techniques were utilized to assign the various NMR signals.     

Cyclic(arylene ether) oligomers containing the phenylphosphine oxide moiety

A series of cyclic(arylene ether) oligomers containing the phenylphosphine oxide moiety has been synthesized by reaction of bis(4-fluorophenyl)phenylphosphineoxide with dihydroxy compounds 1a–d as well as 1,2-dihydro-4-(4-hydroxyphenyl) (2H)phthalazin-1-one in DMF in the presence of anhydrous K₂CO₃ under high dilution conditions. These cyclic oligomers are amorphous and have high solubility in organic solvents. The MALDI-TOF-MS technique has been used as a powerful tool to analyze these cyclic systems. The cyclic(arylene ether) oligomers readily undergo anionic ring-opening polymerization in the melt at 350°C by using potassium 4,4′-biphenoxide as the initiator, affording linear, high molecular weight poly(arylene ether)s containing the phenylphosphine oxide moiety. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 519–526, 1998     

Synthesis and characterization of novel substituted and cyclic benzoquinone derivatives

Novel substituted benzoquinone compounds were synthesized from the reactions of p-chloranil and p-fluoranil with some thiols, amines, and diols in different reaction media. Interesting cyclic compounds like crown ether structures were obtained. The structures of all compounds were characterized by spectroscopic methods and microanalysis.     

A facilitated cyclic ether formation and its potential application in solid-phase peptide and organic synthesis

A "trimethyl lock" system has been known to facilitate lactonization reactions through what has been termed a stereopopulation control mechanism. We have found that a similar trimethyl lock system can also facilitate cyclic ether formation with the concomitant release of a carboxylic acid in the presence of anhydrous tetrabutylammonium fluoride. To study this base-mediated trimethyl lock-facilitated cyclic ether formation, we synthesized fifteen model compounds. All model compounds underwent base-mediated cyclic ether formation in high yields at 0 degree C to room temperature (r.t.) with the concomitant release of the attached carboxylate. Such a system potentially could be used for the development of a two-dimensional linker for solid phase peptide and organic synthesis.     

Formation and reactivity of silacyclopropenes derived from siloxyalkynes: stereoselective formation of 1,2,4-triols

Silver phosphate-catalyzed silylene transfer to siloxyalkynes provided silacyclopropenes possessing a silyl enol ether functional group. Copper-catalyzed insertions of carbonyl compounds afforded the corresponding oxasilacyclopentenes. The embedded silyl enol ether functionality was treated with various aldehydes and a catalytic amount of Sc(OTf)3 to provide dioxasilacycloheptanones, which resulted from an aldol addition/rearrangement. Stereoselective reduction or allylation of the cyclic ketone, followed by n-Bu4NF deprotection, provided high yields of 1,2,4-triols possessing four contiguous stereocenters.     

Formation of Adamantane-Like Structures by Reaction of Titanocene Fluorides with an Iminoalane

Fluorine–nitrogen metathesis in the reaction of a cyclic iminoalane with titanocene fluorides results in unexpected cage compounds. Treatment of one of these compounds with diethyl ether leads to 1 , which contains a titanium–nitrogen double bond stabilized intramolecularly by fluorine.     

Two similar dibenzo cyclic ethers with dissimilar conformations

Two dibenzo cyclic ether compounds, 6,12‐dibromodibenzo[d,i]‐1,2,3,6,7,8‐hexahydro‐1,3‐dioxecin (systematic name: 8,16‐dibromo‐2,4‐dioxatricyclo[12.4.0.0^5,10]octadeca‐5,7,9,14,16,18‐hexaene), C₁₆H₁₄Br₂O₂, (II), and 8,14‐dibromodibenzo[f,k]‐1,5‐dioxa‐1,2,3,4,5,8,9,10‐octahydrocyclododecene (systematic name: 7,19‐dibromo‐11,15‐dioxatricyclo[14.4.0.0^5,10]icosa‐5,7,9,16,18,20‐hexaene), C₁₈H₁₈Br₂O₂, (III), were prepared as scaffolding for phosphate‐anion receptors. In both compounds, the two aromatic rings are linked by three methylene units ortho to the oxygen substituent of each ring. The only difference between the two compounds is the number of methylene units linking the two ether O atoms. The dibenzo cyclic ether with an ether linkage of one methylene unit adopts a chair‐like conformation, where the two aromatic rings are parallel to each other. On the other hand, the dibenzo cyclic ether with an oxygen linkage of three methylene units adopts a bowl‐like conformation. The latter scaffold configuration is the only structure of the two that would allow for the placement of convergent functional groups necessary for the establishment of an anion‐selective binding pocket.     

Controlled cationic alternating copolymerization of various enol ethers and benzaldehyde derivatives: Effects of enol ether structures

Significant structural effects of enol ether monomers were demonstrated in cationic alternating copolymerizations with benzaldehyde derivatives (BzAs). α‐Methyl, β‐methyl, β,β‐dimethyl, and cyclic enol ethers were copolymerized with BzAs by the EtSO₃H/GaCl₃ system with 1,4‐dioxane in toluene at ?78 °C. β‐Methyl and cyclic monomers, β‐monosubstituted compounds, induced copolymerizations with BzAs, some of which were well controlled to yield alternating copolymers with controlled molecular weights (MWs) and narrow MW distributions. Conversely, an α‐methyl vinyl ether (VE) did not copolymerize with BzAs at all, probably due to its high reactivity and unfavorable ketal linkage formations. In addition, a β,β‐dimethyl VE underwent only cyclotrimerizations because of its larger steric repulsion. The product alternating copolymers, especially those with cyclic units, exhibited improved thermal properties compared to those with simple VEs units. Under appropriate conditions, the alternating copolymers selectively degraded into the corresponding cinnamaldehyde derivatives by acid hydrolysis. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1334–1343     

Bioactive C15 acetogenins from the red alga Laurencia obtusa

The petroleum ether extract of the red alga Laurencia obtusa afforded three new C(15) acetogenins (cyclic ether enyne): (12Z)-cis-maneonene-D (1), (12E)-cis-maneonene-E (2), and (12Z)-trans-maneonene-C (3), along with one known cis-maneonene-A (4). Blood neutrophils were prepared, cultured, and incubated for 24, 48, and 72 h in medium with and without isolated compounds. Blood neutrophils were prepared, cultured, and incubated for 24, 48 and 72 h in medium with and without the isolated compounds. Both morphology and DNA fragmentation methods assessed the percentage of neutrophils apoptosis in each culture. In the present study, several observations have been made concerning the apoptosis-inducing or inhibiting effect of 1 and 2. Both compounds had no inhibition of apoptosis but apoptosis was enhanced significantly by aging. However, 1 stimulated apoptosis of normal only at the initial 24 h. After that there was no significant difference in apoptosis with or without compound 1, while 2 stimulated apoptosis at all the times. The apoptosis induced by these two compounds was demonstrated by DNA fragmentation assay and microscopic observation. These observations suggest that compounds 1 and 2 may be involved in regulation of programmed death in the initiation and propagation of inflammatory responses.     

含次环己基的有机硅单体及其低聚体的合成

硅氯仿和环己二烯-1,3进行硅氢加成反应,生成1,3-双(三氯硅基)环己烷,经醇解制得1,3-双(三乙氧硅基)环己烷,与溴化甲基镁反应,制得1,3-双(二乙氧甲硅基)环己环、1-(乙氧二甲硅基)-3-(二乙氧甲硅基)环己烷和1,3-双(乙氧二甲硅基)环己烷,它们在盐酸溶液中分别进行水解,得到各种含次环己基的有机硅低聚体,其中2,2,4,4,11,11,13,13-八甲基-3,12-二氧(杂)-2,4,11,13-四硅(杂)三环[11,3,1,1~(5,9)]十八烷和D_4相似,可能经开环聚合得到聚硅次环己基硅氧烷。