乙腈溶液中对叔丁基杯[4]芳烃与二元脂肪胺的相互作用

用紫外光谱法研究了一系列二元脂肪胺及其类似物与对叔丁基杯[4]芳烃在乙腈溶液中的相互作用，测得其络合比为1：1。探讨了它们的反应机理，并测定了该反应的平衡常数。     

对-叔丁基杯［4］芳烃对聚丙烯热氧稳定性的影响及其动力学研究

制备了对叔丁基杯[4]芳烃和聚丙烯共混体系,用热重法研究了对叔丁基杯[4]芳烃对聚丙烯热氧稳定性的影响,用Coats-Redferm方程进行动力学处理,确定对叔丁基杯[4]芳烃和聚丙烯共混体系的热氧降解的表观反应级数为1．413,表观活化能为154．899kJ/mol。     

有机溶液中C60与对叔丁基杯[8]芳烃间的包合作用

在本工作中, 我们测量了苯、甲苯及四氯化碳中: C60和对叔丁基杯[8]芳烃及共混合液的紫外可见吸收光谱, C60和对叔丁基杯[8]芳烃及其包合物的饱合溶解度, 及包合物的浓度积;推算了上述有机溶液中C60与对叔丁基杯[8]芳烃间包合反应的平衡常数及液相中真正以包合形式存在的包合物的溶解度; 讨论了上述溶剂中包合物的存在形式、沉淀机理及溶剂效应。     

四硫脲基杯[4]芳烃衍生物的合成

对叔丁基杯[4]-1,3-二乙酸乙酯与过量的二乙基三胺反应,生成含有游离氨基的杯芳烃酰胺衍物(2),2再与异硫氰酸苯酯反应合成了含4个硫脲基的杯[4]芳烃衍生物,其结构经1H NMR,IR,MS和元素分析表征。     

5,11,17,23-四叔丁基-25,26,27,28-四[3-(甲氧基羰基)苄氧基]杯[4]芳烃包合性能的研究

杯芳烃是继冠醚和环糊精后的第三代主体化合物 .这类主体分子不仅可以识别和络合阳离子 ,而且还具有包合中性有机分子的性能 [1～ 5] .杯 [4]芳烃类包合物的晶体结构测定表明 ,它们可分为分子内和分子间包合两种类型 [3 ,5] ,前者是客体分子被包合在主体分子的空穴内 ,后者是客体分子被包合在主体分子之间 .对叔丁基杯 [4]芳烃的下沿酚氧基与上沿均可进行化学修饰得到不同的杯 [4]芳烃衍生物 .最早报道的对叔丁基杯 [4]芳烃及其衍生物的分子内包合物是与甲苯或乙腈的 1∶ 1包合物 [4 ,5] ,客体分子依靠 CH3 -π的作用被包结在主体分子内[6]…     

25,27-二(α,γ-二酮苯丁氧基)-26,28-二羟基杯[4]芳烃的合成

以对叔丁基杯[4]芳烃为原料脱除叔丁基得到杯[4]芳烃,再经醚化、缩合两步反应首次合成25,27-二(α,γ-二酮苯丁氧基)-26,28-二羟基杯[4]芳烃,其结构经1H NMR、13C NMR、MS及元素分析表征。研究表明,目标化合物中的α,γ-二酮结构存在酮醇异构现象,在溶液中其酮醇异构体比例近似为1∶2。     

二羟基二羟乙氧基杯[4]芳烃的合成与性质研究

通过杯[4]芳烃与碘乙醇的反应,制得了25,27-二羟基-26,28-二羟乙氧基杯[4]芳烃,经IR,UV,1HNMR,13CNMR和MS等分析证实了产物的结构.用荧光光谱法研究了产物与稀土(Ⅲ)硝酸盐在乙腈溶液中的配位作用,并根据扩展的Hilderbrand-Benesi公式计算了配合物的稳定常数和配位反应的Gibbs自由能变化,结果发现,25,27-二羟基-26,28-二羟乙氧基杯[4]芳烃与稀土(Ⅲ)硝酸盐在乙腈溶液中具有较强的配位能力.     

对叔丁基杯[6]-1,4-2,5-双冠醚的合成、构象及其对阳离子的识别性能研究

采用分步法高产率地合成了系列新型对叔丁基杯[6]双冠醚，并得到了除杯式与1，2，3－交替式构象之外的第3种稳定构象的杯[6]衍生物：1，4－交替式杯[6]-1,4-2,5-双冠醚。研究了它们对碱金属及脂肪胺离子的两相萃取性能，发现杯[6]双冠醚具有与杯[6]单冠醚不同的识别能力。     

杯芳烃—卟啉键连化合物的合成及其紫外—可见光谱特性

本文合成了一种新型的杯芳烃-卟啉模型化合物5及其金属锌的络合物6,用紫外-可见光谱考察了引入对-叔丁基杯[4]芳烃后对卟啉各特征吸收带的影响。     

含苯并噁唑基的硫桥杯[4]芳烃衍生物的合成及结构

在碳酸钾存在下, 对叔丁基硫桥杯[4]芳烃(1)分别与端基二溴代烷和碘甲烷反应, 生成硫桥杯[4]芳烃衍生物2～4. 含端基溴代的硫桥杯[4]芳烃衍生物2和4分别与2-巯基苯并噁唑在碳酸钾存在下反应, 生成硫桥杯[4]芳烃衍生物5a～5d. 通过1H NMR, 13C NMR, IR, MS和元素分析等手段对产物进行了表征. 同时, X射线分析确定了硫桥杯[4]芳烃5b的晶体结构.     

对磺酸基杯[4]芳烃与血红蛋白相互作用的光谱研究

用荧光光谱法和紫外可见分光光度法研究了表面活性剂存在下对磺酸基杯[4]芳烃与牛血红蛋白的相互作用机理。由Stern-Volmer方程及紫外可见吸收光谱图确定对磺酸基杯[4]芳烃对血红蛋白的荧光猝灭过程为动态猝灭,求出了猝灭常数。由热力学参数判断二者之间的作用力主要是疏水作用。依据能量转移理论得出荧光给体-受体间的距离r。在同步荧光光谱中,对磺酸基杯[4]芳烃的加入对血红蛋白构象的改变不大。     

Influences of Hard Donor on Cation Selectivities Closing to Soft Selenium Donor in Tweezer-like Calix[4]arene Receptors

Three novel 25,27-dihydroxy-26,28-bis(3-benzylselenopropoxy)-5,11,17,23-tetra-tert-butylcalix[4]-arene (2),25,27-dihydroxy-26,28-bis[3-(2-hydroxyethylseleno)propoxy]-5,11,17,23-tetra-tert-butyl-calix[4]arene (3) and 25,27-dihydroxy-26,28-bis(3-propylselenoproppxy)-5,11,17,23-tetra-tert-butyl-calix[4]arene (4) were synthesized for the comparison of their ion-selectivity in ion-selective electrodes (ISE). X-ray structure of the CH/π complex of 4.CH2Cl2 was elucidated. ISEs based on 2-4 as neutral ionophores were prepared, and their selectivity coefficients for Ag (logKAg,M^pot) were investigated against some main group metal ions and transition metal ones using the fixed interference method (FIM). These ISEs showed excellent Ag^ selectivity over most of the interfering cations examined. It is evident that the stronger Hg^2 interference may not be produced while hard donors (hydroxy) are close to the soft selenium donors.     

一对含有苯甲醛基修饰的杯芳烃异构体的晶体结构以及它们与铽离子配位的光物理性质

Two calix[4]arene isomers with benzaldehyde moieties, i.e., 5,11,17,23-tetra-tert-butyl-25,27-bis[2-(o-formyl-phenoxy)ethoxy]-26,28-dihydroxycalix[4]arene (3) and 5,11,17,23-tetra-tert-butyl-25,27-bis[2-(p-formylphenoxy)-ethoxy]-26,28-dihydroxycalix[4]arene (4), were synthesized according to a newly designed route in high yields, and their crystal structures have been determined by X-ray crystallographic study. The photophysical behavior on complexation of calix[4]arene derivatives 3 and 4 with terbium(Ⅲ) nitrate was investigated in anhydrous acetonitrile at 25℃ by UV-Vis and fluorescence spectroscopies. The crystallographic structure of 3 indicated that the eight oxygen atoms formed a preorganized ionophoric cavity due to intramolecular π-π stacking, which could encapsulate lanthanide ions tightly. In sharp contrast, the compound 4 formed a linear array by intermolecular π-π stacking, hence the oxygen atoms of pendant arms could not coordinate with metal ions, giving a poor binding ability to Tb^3 . The absorption spectra of 3 with Tb^3 showed clearly a new broad intense absorption at 385nm. Interestingly, the narrow emission line spectrum has also been observed for compound 3 with Tb^3 , and the results obtained were discussed from the viewpoint of energy transfer mechanism between host structures and the properties of lanthanide ions.     

Synthesis of Flavin–Calix[4]arene Conjugate Derivatives

The synthesis of two new flavin substituted calix[4]arene derivatives, 9 and 10 , is described. The first flavin substituted calix[4]arene derivative 9 was synthesized by the reaction of 3‐methylalloxazine ( 5 ) with 25,27‐bis(3‐bromopropoxy)‐26,28‐dihydroxy‐5,11,17,23‐tetra(tert‐butyl)calix[4]arene ( 4 ) in high yield (92%). The other derivative 10 was prepared from 3‐methylalloxazine‐1‐acetic acid ( 7 ) and 25,27‐bis(3‐cyanopropoxy)calix[4]arene ( 3 ). All new compounds were characterized by a combination of FT‐IR and ¹H‐NMR spectroscopy, and elemental‐analysis techniques.     

Calix[4]azacrown and 4-aminophthalimide-appended calix[4]azacrown: synthesis, structure, complexation and fluorescence signaling behaviour

The synthesis and single crystal structure of 25,27-(diamidomonoazacrown-5)-calix[4]arene (L), calix[4]arene capped by a diamide bridge in the 1,3-position on the lower rim, which forms a supramolecular dimer in the solid state via intermolecular hydrogen bonding, are described. A 4-aminophthalimide (AP) fluorophore has been regioselectively linked to the secondary amino function of the azacrown unit with a dimethylene spacer to construct N-(4-aminophthalimidoethyl)calix[4]azacrown (APL), a fluorescent sensor, via a fluorophore-spacer-receptor architecture. Fluorescence quantum yield and lifetime of APL have been measured to be lower than those of the bare fluorophore (AP) due to the photoinduced intramolecular electron transfer (PIET) between the fluorophore and the receptor moieties of the molecule. In the presence of transition metal ions, fluorescence enhancement of is observed suggesting the binding of the metal ion to the sensor. Complexation properties of APL with transition metal ions are investigated using UV-vis spectroscopy. A 1 : 1 stoichiometry of the complex is determined from a Job plot and the corresponding association constants for the various metal ions are evaluated. Fe(3+) and Cu(2+) ions have the largest association constants (K= 2.3 x 10(5) M(-1) and 1.6 x 10(5) M(-1) respectively) compared to other metal ions indicating that they form complexes selectively with APL.     

Alkali Metal Complexation. Binding Properties of cone and partial-cone Calix[4]arenes Bearing a Mixed (O 2 , O 2 ') Donor Set (O = Phosphine Oxide; O ' = Amide or Ester)

The stability constants of alkali metal complexes obtained from the followingO-substituted calix[4]arenes were determined by UV/Vis spectroscopy inmethanol at 20°C: 5,11,17,23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28-bis(diphenylphosphinoylmethoxy)calix[4]arene(cone-1), 25,27-syn-26,28-anti-5,11,17,23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28-bis(diphenylphosphinoylmethoxy)calix[4]arene (paco-1),5,11,17,23-tetra-tert-butyl-25,27-diethoxycarbonylmethoxy-26,28-bis(diphenylphosphinoylmethoxy)calix[4]arene(cone-2) and25,27-syn-26,28-anti-5,11,17,23-tetra-tert-butyl-25,27-diethoxycarbonylmethoxy-26,28-bis(diphenylphosphinoylmethoxy)calix[4]arene(paco-2). All ligands form 1:1 complexes with alkali metal cations. The amide-containing calixarenes were found to be more efficient for alkali metalcomplexation than those bearing ester substituents. While sodium ions are selectivelycomplexed by the two mixed amide-(phosphine oxide) calixarenes, the twoester-containing isomers cone-2 and paco-2 turned out to be selective towards potassium and rubidium ions, respectively. With allfour ligands the lowest stability constants were found for the lithium andcesium ions.     

Enantioselective Recognition of Calix[4]arene Derivative Bearing Bicyclic Guanidinium for D/L Amino Acid Zwitterions

The p‐tetra‐tert‐butyl calix[4] arene derivatives (3 and 4) with (5,5) chiral bicyclic guanidinium, as the receptors of amino acid zwitterions, have been synthesized via a O‐alkylation reaction of p‐tetra‐tert‐butyl calix [4] arene with cbJoromethyl chiral bicyclic guanidinium 2 in the presence of anhydrous K₂CO₃ in acetonitrile. The results obtained from liquid‐liquid competitive extraction experiments indicate that the two receptors may selectively recognize L‐aromatic amino acids, and that the enantioselective recognizability of the receptor 4 with two chiral bicyclic guanidinium units reachs up to about 90% for L‐Phe.     

Potassium Sensing Calix[4]arene Crown Ethers

1,3-Alternate calix[4]arene crown-5 (1) and corresponding biscrown-5 (2) were synthesized and the complexation behavior with alkali metal ions examined. For both 1 and 2, potassium ion was selectively extracted from aqueous phase into organic phase over other alkali metal ions based on two phase extraction experiment. The complexation ratio between calix[4]arene biscrown-5 (2), in which two crown cavities connect to the calix[4]arene framework by 1,3-alternate fashion and potassium metal ion is found to 1:1 by proton NMR spectroscopy and extraction equilibria. Association constants (logK_a) for 1 and 2 were determined to give 2.51 and 3.49, respectively.     

Spectroscopic Study of Molecular Recognition of Ions by Chromogenic Calix[4]arene Derivatives

The complexation properties of three new chromogenic calix[4]arenes ( 1a–c) with aliphatic amines and alkali/alkali earth metal ions have been studied by UV/Vis spectroscopy. 1c shows the greatest complex forming ability and it is selective for Li⁺, Ca²⁺ and certain amines in polar solvents.