磺化硫杂杯[4]芳烃修饰纳米金的制备及对水溶液中Cr3+的比色检测

在不需外加还原剂的条件下一步原位合成了磺化硫杂杯[4]芳烃修饰的纳米金,并将其作为比色探针对金属离子进行检测。研究表明,磺化硫杂杯[4]芳烃修饰的纳米金能够选择性的识别CrP3+P,其检测限可达到1μM。     

样品堆积富集毛细管电泳测定磺化杯芳烃

利用毛细管电泳技术,建立了一种分离、测定磺化杯芳烃的方法。研究了缓冲液浓度和pH、分离电压和进样时间等因素对分离性能的影响。采用磷酸缓冲液(pH 8.7)作分离介质,分离电压15 kV时,6 min内可实现对磺化杯[4]芳烃、磺化杯[6]芳烃和磺化杯[8]芳烃的完全分离。该法充分利用了样品堆积效应,无需任何添加剂,与文献相比简单快速。磺化杯芳烃的浓度(0.001 0~1.0 mmol.L-1)与峰高呈良好的线性关系,其相关系数均优于0.999 3,检出限分别为0.43,0.25和0.32μmol.L-1。     

杯芳烃和柱芳烃桥梁部位的衍生及其功能化

随着大环化学的快速发展,对杯芳烃、柱芳烃及其他类似化合物的桥梁亚甲基部位进行高效修饰的方法日益引起人们的关注.桥梁部位修饰后的大环衍生物,在不改变其原有属性的基础上增加了新的功能,不仅可以引入更多的功能基团,而且可以通过主客体的自组装行为,进一步拓展杯芳烃和柱芳烃等超分子大环在药物递送、化学传感、荧光体系构建等诸多领域的应用.本文对杯芳烃和柱芳烃桥梁部位修饰的研究进展进行了综述.按照修饰方法的不同进行分类,系统阐述了杯芳烃和柱芳烃桥梁部位修饰的方法、修饰后结构的变化,以及相应的应用拓展,并进一步讨论了其未来发展所面临的机遇与挑战.     

磺化杯芳烃与二苯胺重氮盐的包结物

磺化杯芳烃与二苯胺重氮盐形成摩尔比为1：1的包结物，在磺化杯芳烃存在时，二苯胺重氮盐的吸光强度下降，吸收峰红移，核磁共振氢谱的化学位移向高场移位。杯芳烃的环越大，与重氮盐的结合常数越大。在磺化杯芳烃的存在下，重氮盐的热稳定性提高，同时仍保持较高的光敏性。     

杯芳烃酰胺类衍生物对金属离子的萃取性能

以吗啉和六氢吡啶修饰的四种对叔丁基杯[n]芳烃酰胺类衍生物(n=6,8)为萃取试剂,研究了它们对Na+,K+及部分过渡金属等十种金属离子的萃取作用.结果表明此类杯芳烃酰胺类衍生物对过渡金属离子有良好的选择性识别作用.其中,吗啉取代基修饰的杯[8]芳烃萃取效果最好.     

杯芳烃LB膜修饰电极及其识别性能

为了得到性能好的修饰电极,尝试使用不同的杯芳烃制作LB膜修饰电极,研究了不同空腔大小的和不同上缘取代基的杯芳烃LB膜成膜情况,发现对叔丁基杯芳烃和对烯丙基杯[4]芳烃都可以得到稳定的LB膜,杯环大小可以影响成膜的平均分子占有面积。不同取代基的杯芳烃识别金属铊离子的性能不同,叔丁基基本没有特别的响应,烯丙基有较好的响应,这应归因于电极表面烯丙基对铊离子的吸附或络合作用。     

超分子砌块间苯二酚杯芳烃的研究进展

间苯二酚杯芳烃是一类以间苯二酚为单元的杯芳烃, 作为新一代超分子砌块, 在分子催化、分子识别、超分子自组装、晶体工程和纳米材料等方面都获得了广泛的应用, 已成为当今化学研究的新热点. 综述了间苯二酚杯芳烃的功能化修饰及其应用新进展.     

磺化杯芳烃的超分子组装体构筑及其功能

磺化杯芳烃具有非常强的分子键合能力, 被广泛用于水相超分子自组装研究. 介绍了磺化杯芳烃与客体阳离子形成超分子组装体的主要驱动力和形貌调控因素; 总结了包括主体诱导客体聚集、客体诱导主体聚集及主客体共组装在内的三种主要聚集模式; 并展望了其在刺激响应材料、药物传递载体、多功能超分子平台和超分子催化等领域的重要应用前景.     

新型正丁醛杯[4]芳烃醚衍生物的合成

以正丁醛间苯二酚杯[4]芳烃为原料,经酯化、水解、酰氯化后再与9-蒽甲醇反应,合成了蒽单取代的正丁醛间苯二酚型杯[4]芳烃醚衍生物。其结构经1H NMR和IR表征。     

一类新型超分子主体——硫代杯芳烃的研究进展

硫代杯芳烃是一类以硫原子取代桥联亚甲基的新型杯芳烃, 作为新一代超分子砌块, 在分子识别、超分子自组装、晶体工程和纳米材料等方面都获得了广泛的应用, 已成为当今超分子化学研究的新热点. 综述了硫代杯芳烃及其衍生物的合成、功能化修饰及应用方面的研究进展.     

同轴式电化学电喷雾质谱离子源研究蒽电化学衍生十二胺

提出一种同轴式电化学电喷雾质谱离子源, 用于电化学与质谱分析在线联用. 离子源结构简单, 造价低廉, 容易制作. 离子源内的电化学反应器工作在两电极模式, 利用自制的悬浮在电喷雾高压上的无线电化学工作站控制. 使用二苯基蒽或三乙胺的乙腈溶液作为分析物, 全面测试了离子源的性能, 包括电势控制精度、电化学转化率、响应时间和抗污能力等. 测试溶液添加浓度约10 mmol·L^-1的银盐作为电解质和去极剂, 将溶液电阻降至250 Ω, 提高了在线联用的电势控制精度. 所测二苯基蒽溶液流动时的伏安曲线与常规三电极体系的循环伏安曲线基本一致. 在3.6 μL·min^-1的流速下, 离子源的响应时间不超过5 s, 三乙胺的电化学转化率高达77%. 利用此离子源, 研究了蒽的电化学衍生反应, 衍生试剂为十二胺. 蒽作为一种非极性物质, 不能为常规电喷雾质谱检测. 而利用电化学电喷雾质谱离子源, 蒽首先发生电化学氧化反应, 进而与衍生试剂作用生成各种极性物质, 被电喷雾质谱检测. 依据质谱检测到的主要反应产物的相对分子质量与结构提出了衍生反应的机理, 有助于理解蒽的复杂电化学行为.     

4,5-dimethylthio-4'-[2-(9-anthryloxy)ethylthio]tetrathiafulvalene, a highly selective and sensitive chemiluminescence probe for singlet oxygen

4,5-Dimethylthio-4'-[2-(9-anthryloxy)ethylthio]tetrathiafulvalene has been designed and synthesized as a highly selective and sensitive chemiluminescence (CL) probe for singlet oxygen ((1)O(2)). The design strategy for the probe is directed by the idea of photoinduced electron-transfer process and carried out through the incorporation of electron-rich tetrathiafulvalene unit into a reactive luminophore of anthracene specific for (1)O(2). Upon reaction with reactive oxygen species (ROS), such as hydrogen peroxide, hypochlorite, superoxide, hydroxyl radical, or (1)O(2), the probe exhibits both strong CL response to and high selectivity for (1)O(2) only, rather than the other ROS. This remarkable CL property permits (1)O(2) to be distinguished easily from the other ROS and makes the probe possible to be used widely for (1)O(2) detection in many chemical and biological systems and even in light water (H(2)O) environments. This applicability has been demonstrated by monitoring the (1)O(2) generation in a metal-catalyzed decomposition system of tert-butyl hydroperoxide. Moreover, the CL reaction mechanism of the present system is also discussed, clearly confirming that the introduction of electron-rich tetrathiafulvalene into the 9-position of anthracene can greatly activate its reactivity toward (1)O(2).     

Recombination of polycyclic aromatic hydrocarbon photoions with electrons in a flowing afterglow plasma

A new technique, flowing afterglow with photoions (FIAPI), has been developed to measure the rate coefficient for the recombination of complex ions, and, in particular, polycyclic aromatic hydrocarbon (PAH) cations with electrons. The method is based on the flowing afterglow Langmuir probe - mass spectrometer apparatus at the University of Rennes I. A helium plasma is generated by a microwave discharge in a He buffer gas and downstream, a small amount of argon gas is injected to destroy any helium metastables. A very small amount of neutral PAH molecules is added to the afterglow plasma by evaporation from a plate coated with the PAH to be studied. PAH ions are then produced by photoionization of the parent molecule using a pulsed UV laser (157 nm). The laser beam is oriented along the flow tube and so a constant spatial concentration of photoions is obtained. The electron concentration along the flow tube is measured by means of a movable Langmuir probe. Ion concentration decay in time is measured at a fixed position using a quadrupole mass spectrometer which is triggered by the laser pulse. The recombination of anthracene and pyrene cations has been studied using this technique and we have found a recombination rate of (2.4 +/- 0.8) x 10(-6) cm(3) s(-1) for anthracene and (4.1 +/- 1.2) x 10(-6) cm(3) s(-1) for pyrene.     

用能量转移探测萘-蒽二元分子体系的构象变化

合成了一个带有末端取代的能量给体-萘和能量受体-蒽的开链冠醚（DSA）.吸收光谱表明两个发色团之间在基态时没有相互作用.选择性激发萘观察到萘的荧光强度下降, 同时伴随着蒽的发射增强, 表明发生了从萘至蒽的单重态-单重态能量转移.能量转移效率受溶剂极性的影响.可以认为在极性小的溶剂如苯中－OCH2CH2O－单元中的中心C－C键主要以反式存在,而在极性大的溶剂如乙腈中则以邻交叉式为主.因此,开链冠醚末端取代的萘和蒽之间的距离随着溶剂极性的增大,能量转移效率却随之降低.表明能量转移可以用于探测以柔性配体键连接的给体-受体体系在不同极性溶剂中的构象变化特性.     

Polyaromatic Profluorescent Nitroxide Probes with Enhanced Photostability

Novel profluorescent mono‐ and bis‐isoindoline nitroxides linked to napthalimide and perylene diimide structural cores are described. These nitroxide‐fluorophore probes display strongly suppressed fluorescence in comparison to their corresponding non‐radical diamagnetic methoxyamine derivatives. The perylene‐based probe possessing two isoindoline systems tethered through ethynyl linkages was shown to be the most photostable in solution, demonstrating significantly enhanced longevity over the 9,10‐bis(phenylethynyl)anthracene fluorophore used in previous profluorescent nitroxide probes.     

具有大斯托克位移的荧光探针分子

用荧光法来监视多个生理参数时,需要几个不同的荧光探针分子.这些探针分子要被同一波长激发,但是具有明显分离的、不同的发射波长.目前,大多数荧光探针只有小的斯托克位移(50-90 nm),从而限制了它们在多个物质同时检测上的应用.在这项工作中,我们提出了一个新的分子探针设计:受体-荧光分子1-间隔-荧光分子2(简称RFSF...     

辽河和孤岛渣油供氢能力与生焦趋势

首先以蒽为化学探针对孤岛、辽河和胜利减压渣油及其四组分的氢转移能力进行表征,原理是,蒽与渣油在３５０～４００℃热反应,渣油向蒽供氢,使蒽转化成９,１０－二氢蒽,用气相色谱分析定量测定热反应产物中的９,１０－二氢蒽,并计算出单位重量油样供氢量;然后在４００℃下热处理测定三种渣油的生焦诱导期（定义为生焦０１％时所用时间）。结果发现：虽然它们四组分相近,但氢转移潜力相差较大,特别是它们的沥青质的氢转移能力相差悬殊;渣油热生焦诱导期长短与它们氢转移能力趋势一致     

Investigation of state of anthracene in solid and liquid solutions and on the surface of an adsorbent

It has been shown that when solvatochromism is used to investigate the chemical properties of a medium in which there is a probe molecule, the structure of the immediate surroundings of the probe should be taken into account. In investigating the nature of active centers of an adsorbent, anthracene is a convenient probe, since evaluations of the contributions of different types to the shift of the spectrum of its S₁ S₀ transition can be made with adequate accuracy on the basis of the simplest model representations. Spectroscopic results have been used in examining the structure of the modified layer of a cation-active substance on the surface of a mineral ion exchanger.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 21, No. 6, pp. 686–693, November–December, 1985.     

Hg sensing in aqueous solutions: an intramolecular charge transfer emission quenching fluorescent chemosensors

Compounds 4a and 4b, comprising an anthracene moiety as the fluorophore and a pair of dithiocarbamate functionalities as ligating groups, were designed as fluorescent chemosensors for Hg(II). In aqueous solvent systems, upon excitation, in addition to the normal emission bands of locally excited (LE) state of anthracene, both compounds show a prominent pH-independent intramolecular charge transfer (ICT) emissive band, which can be modulated by Hg²⁺ binding. The systems can be exploited to develop a fluorescent sensitive probe for Hg²⁺.     

Dual fluorescence of 2-methoxyanthracene derivatives

The time-resolved emission properties of selected anthracene derivatives, namely anthracene (1a), 2-methylanthracene (1b), 2-chloroanthracene (1c), 2-methoxyanthracene (1d), 2-methoxy-6-methylanthracene (1e), 2-(N,N'-dicyclohexylureidocarbonyl)-6-methoxyanthrace ne (1f), 2-(6-methoxyanthr-2-yl)-4,4-dimethyl-2-oxazoline (1g), 2-(6-methoxyanthr-2-yl)-pyridine (1h), and N-cyclohexylanthracene-2-carboxamide (1i) were investigated. In contrast to anthracene (1a), 1b, and 1c, the 2-methoxy-substituted anthracene derivatives 1d-1h exhibit two emission lifetimes. The determination of the lifetimes at different emission wavelengths and additional time-resolved emission spectroscopy (TRES) reveal that the dual emission originates from two different, interconvertible emissive species, with the s-cis and s-trans conformation relative to the exocyclic C2-O bond. The energy difference between the two emissive species is very small (<0.1 eV) both in the ground and in the excited state. The larger energy difference between the conformers in the excited-state is responsible for the interconversion within the singlet excited-state lifetimes of the s-cis into the s-trans conformations leading to coupled decay kinetics. The proposed mechanism for the dual emission was qualitatively supported by theoretical studies on CASSCF and DFT level. In addition, the emission lifetimes of the fluoride- and pH-sensitive fluorescent probes 1f and 1g change upon addition of fluoride or acid, respectively, so that in these cases the detection of the fluorescence lifetime may be used complementary to the steady-state fluorimetric detection of these analytes.