卟啉多枝分子合成与分子内能量转移、双光子吸收性能研究

以三苯胺或硝基苯为端基, 合成了三个卟啉多枝分子: 5-(4-硝基苯甲酰氧基)苯基-10,15,20-三-(4-溴苯基)卟啉(TPP-NO₂)、5-(4-硝基苯甲酰氧基)苯基-10,15,20-三-(4-二苯胺基-1-苯乙烯基)苯基卟啉(TPP-X₃)和5,10,15,20-四-(4-二苯胺基-1-苯乙烯基)苯基卟啉(TPP-X₄), 进行了红外光谱、核磁共振光谱和质谱表征. 比较研究了分子“枝”、“核”不同键合方式与不同对称结构对分子的线性光谱、非线性光谱以及分子内能量转移行为的影响. 在钛宝石激光器(800 nm)和Nd∶YAG倍频光(532 nm)泵浦下, 样品溶液均发出卟啉环特有的红色荧光——前者系双光子吸收机制“上转换”荧光, 后者则为双光子吸收与分子内能量转移机制“下转换”荧光. 飞秒Z-scan技术测得样品双光子吸收截面最大可达130 GM, 与四苯基卟啉(TPP)同等测试条件下的双光子吸收截面相比增大了两个数量级.     

芳基吡啶类Fe3+荧光探针的合成与分析应用

设计合成了两种新型的以2-苯基苯并噻唑为荧光团、N-(2-吡啶甲基)胺为识别基团的铁离子荧光分子探针2-(4-N-2-吡啶甲胺基)苯基-1,3-苯并噻唑(A1)和2-(4-N,N双2-吡啶甲胺基)苯基-1,3-苯并噻唑(A2),化合物结构用UV,IR,1HNMR和13CNMR进行了表征,并考察了探针的荧光特性.结果表明荧光分子探针A2在CH3 CH2OH/H-12O(1∶1,V/V)溶液中,能从常见的金属离子中以95％的荧光淬灭率选择性地识别铁离子,对Fe3+线性响应范围在0.15～1.3 μ mol/L之间,且检出限达10 nmol/L.     

一种基于三苯胺类共轭聚合物荧光信号开启的汞离子检测方法

通过Suzuki反应合成出主链中含9,9-二(4-二苯胺基苯基)-3,6-芴的蓝光共轭聚合物—聚[2,7-(9,9-二辛基芴)-co-3,6-(9,9-二三苯胺基芴)] (36PFT).36PFT可特异地与I-相互作用,并淬灭36PFT的荧光.当I-的浓度为0.24 mmol/L时,36PFT的荧光淬灭程度可达95％,...     

一种三足蒽三唑化合物的合成及其对汞离子荧光识别

通过点击反应合成了一个以苯为中心含蒽荧光团的三足三唑受体分子1.在CH_3CN-H_2O(V∶V=9∶1)溶液中,受体分子1对汞离子表现出很好的荧光淬灭响应.其荧光淬灭率为75%,对汞离子的检测极限为6.1×10~(-6) mol/L.1H NMR滴定表明受体分子中三唑环中的三个N原子与中心离子参与了配位.     

玛卡荧光碳点的合成及用于苦味酸的荧光检测

以玛卡为碳源,采用水热法制备荧光碳点。碳点水溶液在激发波长为315 nm时,最大荧光发射波长为425 nm。在玛卡荧光碳点的磷酸盐缓冲液(0.2 mol/L,pH 5.8)中,加入苦味酸,其荧光被猝灭,基于此建立了以玛卡荧光碳点为荧光探针测定苦味酸的方法。本方法检测苦味酸的线性范围为0.4~80 mmol/L,相关系数为0.9978,检出限为110 nmol/L(S/N=3),本方法线性范围宽、灵敏度高、响应快(2 min内),选择性和抗干扰能力良好。用于实际水样中苦味酸的检测,加标回收率为92.0%~110.0%,结果令人满意。     

浊点萃取、荧光淬灭法测定痕量维生素B2

根据高聚物的强富集作用及荧光淬灭法灵敏度高等特点,提出了浊点萃取、荧光淬灭法测定痕量维生素B2的新方法。主要研究了萃取剂、萃取时间、酸度、铬蓝黑的浓度、淬灭时间等因素的影响,并探讨了利用维生素B2淬灭铬蓝黑R的机理。实验表明,在最佳条件下,聚乙二醇辛基苯基醚～硫酸铵体系对维生素B2的一次萃取率可达到98%,利用该方法测定维生素B2的线性范围为:1.2×10-7～1.44×10-5g/L;回归方程:ΔF=0.13+3.0C;相关系数为0.9974;检出限:8.4×10-8g/L。该方法用于样品测定,相对标准偏差在2.9%～5.8%之间。     

酸诱导-浊点萃取-荧光淬灭法测定盐酸胺碘酮

测量了盐酸胺碘酮溶液的荧光光谱及将不同浓度的胺碘酮溶液加入到十二烷基硫酸钠(SDS)溶液中的荧光光谱,结果发现,加入盐酸胺碘酮后SDS荧光淬灭的现象.在一定浓度范围内,盐酸胺碘酮的加入量与SDS荧光淬灭值成良好的线性关系.据此,利用SDS作为荧光探针,建立了酸诱导-浊点萃取(ACPE)富集,荧光淬灭法测定片剂及血清样品中盐酸胺碘酮含量的方法.在优化了的实验条件下,测定条件为:激发波长227 nm,发射波长330 nm;标准曲线的线性范围为0.6~21 mg/L;检出限为0.18 mg/L;片剂及血清样品中加标回收率在98.4%~102.2%之间。     

恒波长同步荧光淬灭法测定食品中苏丹红Ⅱ的研究

本文建立了恒波长同步荧光淬灭测定苏丹红Ⅱ的新方法.研究表明,苏丹红Ⅱ对硫酸奎宁的荧光有淬灭作用,通过Stern-Volmer方程的计算和紫外吸收光谱研究,得到苏丹红Ⅱ对硫酸奎宁荧光的淬灭机制主要为动态淬灭,且淬灭程度与苏丹红Ⅱ的含量呈线性关系.当△λ=30 nm时,该方法的线性范围为1.0×10-6 ～5.0×10-4mol/L,检出限为2.393×10-11 mol/L.     

基于金属配位和主客体相互作用分级自组装构筑超分子凝胶

将金属配位和主客体相互作用引入到同1个超分子体系中,设计合成了2个超分子单体1和2.通过这2个超分子单体分级自组装形成的交联网状超分子聚合物构建了一种多重刺激响应性和良好自修复性能的超分子凝胶.同时,进一步将具有聚集诱导发光性能的四苯乙烯引入到这种超分子体系中,以赋予超分子体系新颖的发光性能.单体分子1是由中间为双苯并24-冠-8的冠醚连接2个四苯基乙烯荧光生色团,两端为2个三联吡啶分子构成的1个主体分子.单体分子1两端的三联吡啶基团可以与过渡金属Zn(OTf)2进行金属配位形成线型超分子聚合物3;而中间的冠醚基团与双二级铵盐客体分子2通过主客体相互作用进一步形成交联超分子聚合物4.当该交联超分子聚合物的浓度达到30 mmol/L时,可形成荧光超分子聚合物凝胶.通过核磁共振(1H-NMR和DOSY)与黏度等测试方法,证明了线形和交联超分子聚合物的形成,并进一步通过流变的测试证明了超分子聚合物凝胶的形成及其良好的自修复性能.除此之外,由于引入的主客体相互作用以及金属配位固有的刺激响应性,该荧光超分子聚合物凝胶表现出对温度、p H值、K+离子和竞争配体的刺激响应性能.     

新型D-π-A结构芪类衍生物的合成及其光学性质

以对硝基甲苯为起始原料,与NBS经溴代反应制得对溴甲基硝基苯(2);2与亚磷酸三乙酯经取代反应得4-硝基苯基膦酸二乙酯(3);4-醛基苯基亚氨基二乙酸二乙醇与3或对硝基苯乙腈分别经Wittg-Homer反应和Knoevenagel缩合反应合成了两种新型芪类化合物(5和7),其结构经1H NMR,13C NMR,IR和ESI-MS表征.用UV-Vis和荧光光谱研究了5和7的光学性质.结果表明:5和7的最大吸收峰均位于410 nm;5的荧光发射峰位于529nm,较7红移26nm,发射强度提高129倍.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.