Cover Picture: Construction of Crown Ether‐Stoppering [3]Rotaxanes Based on N‐Hetero Crown Ether Host (Chin. J. Chem. 7/2017)

The cover picture shows shows the construction of crown etherstoppering [3]rotaxanes based on N ‐hetero crown ether host. Usually, crown ethers play the role of host macrocycles to combine with the guest molecules in the construction of rotaxanes. Based on the fact that crown ethers have large dimension, two [3]rotaxanes containing four crown ether units were designed and synthesized, of which, two N ‐hetero crown ether components were employed as the macrocyclic hosts to assemble the mechanically interlocked framework by using a template‐directed clipping reaction while bis (metaphenylene‐26‐crown‐8) located on two sides of template diammonium acting as the stoppering groups of [3]rotaxanes. More details are discussed in the article by Yin et al. on page 1050–1056.

     

Self－assembly of Novel Hetero[3]rotaxane, [2]Rotaxanes and [2]Catenane

One linear template 13 and one cyclophane template 15, both incorporating two electron rich 1,4‐dialkoxybenzene units and one diamide unit, have been synthesized. By utilizing donor‐acceptor interaction and/or intermolecular hydrogen bonding assembling principles, one novel hetero[3]rotazane 22·4Cl, possessing one neutral and one tetracationic ring components, has been synthesized from 13, through neutral [2]rotaxane 21 as intermediate. With 15 as template, tetracationic [2]catenane 23·4PF₆ was assembled by using donor‐acceptor interaction, but no neutral [2]rotaxane could be obtained under the typical conditions of hydrogen bonding assembling principle. The interlocked supramolecular compounds have been characterized and their spectral properties are investigated.     

Self-assembly of Novel Hetero[3]rotaxane,[2]Rotaxanes and [2]Catenane

One linear template 13 and one cyclophane template 15, both incorporating two electron rich 1,4-dialkoxybenzene units and one diamide unit, have been synthesized. By utilizing donor-acceptor interaction and/or intermolecular hydrogen bonding assembling principles, one novel hetero[3]rotaxane 22·4Cl, possessing one neutral and one tetracationic ring components, has been synthesized from 13, through neutral [2]rotaxane 21 as intermediate. With 15 as template, tetracationic [2]catenane 23·4PF6 was assembled by using donor-acceptor interaction, but no neutral [2]rotaxane could be obtained under the typical conditions of hydrogen bonding assembling principle. The interlocked supramolecular compounds have been characterized and their spectral properties are investigated.     

Cyclodextrin‐Based Size‐Complementary [3]Rotaxanes: Selective Synthesis and Specific Dissociation

α‐Cyclodextrin (CD)‐based size‐complementary [3]rotaxanes with alkylene axles were prepared in one‐pot by end‐capping reactions with aryl isocyanates in water. The selective formation of [3]rotaxane with a head‐to‐head regularity was indicated by the X‐ray structural analyses. Thermal degradation of the [3]rotaxanes bearing appropriate end groups proceeded by stepwise dissociation to yield not only the original components but also [2]rotaxanes. From the kinetic profiles of the deslippage, it turned out that the maximum yield of [2]rotaxane was estimated to be 94 %. Thermodynamic studies and NOESY analyses of such rotaxanes revealed that [2]rotaxanes are specially stabilized, and that the dissociation capability of the [3]rotaxanes to the components can be adjusted by controlling the structure of the end groups, direction of the CD groups, and length of the alkylene axle.     

Characteristics of Lariat Crown Ether‐Copper (II) Ion‐Selective Electrodes

An ion‐selective electrode using ionophore 2′‐picolyl sym‐dibenzo‐16‐crown‐5 ether as membrane carrier, sodium tetraphenylborate (NaTPB) as an anion excluder, and 2‐nitrophenyl‐octyl ether (NOPE) as the plasticing solvent mediator has been successfully developed. This electrode exhibits al in ear response with a slope of 42 mV/decade in concentration ranging from 10^?5 molL^?1 to 10^?1 molL^?1, slightly larger than the 30 mV expected from the one‐to‐one complex. The reason for the super‐Nernstain slope is the partial dimmer formation in side the membrane of the electrode, because this dimmer [Cu(C₂₅H₂₇NO₆)₂(H₂O)₂] 2ClO₄, has been isolated and confirmed by single crystal X‐ray crystallography. The detection limit for the cop per (II) ion was estimated to be 1 × 10^?6 molL^?1. Electrades composed of other plasticing solvent mediators such as tris(2‐ethylhexyl) phosphate (TOP), bis (2‐ethylhexyl) sebacate (DOS) and dibutyl phthalate (DBP) were also investigated. Stability constants (logKs) of the two to one and the one to one 2‐picolylsym‐dibenzo‐16‐crown‐5 ether‐Cu (II) complexes have been determined by potentiometric titration in methanol.     

Construction of Pseudorotaxanes and Rotaxanes Based on Cucurbit[n]uril

¹H-NMR spectroscopic analysis indicates that cucurbit[7]uril can form a stable inclusion complex with 1,6-hexanediamine, while cucurbit[5]uril cannot form pseudorotaxane with 1,6-hexanediamine under our experimental conditions. This was confirmed by the crystal structure of the complex. The cavity of cucurbit[8]uril seems to be large for binding 1,6-hexanediamine efficiently. And a simple, mild, high-yield (>80%) method has been described for the synthesis of rotaxanes through the self-assembly of pseudorotaxanes of cucurbit[n]uril (n=6, 7)/1, 6-hexanediamine and sodium tetraphenylborate. The obtained rotaxanes are held intact solely by noncovalent interactions, and are characterized by elemental analysis, ¹H-NMR, ESI-MS and MALDI-TOF MS.     

香豆素冠醚双功能化杯[4]芳烃的合成

以对叔丁基杯[4]芳烃为原料,经碱催化合成了26,28-双(4,7-双甲氧基香豆素)-5,11,17,23-四叔丁基杯[4]-冠-6(2)。其结构经1H NMR,IR和元素分析表征,2为锥形结构。     

A Novel Colorimetric Reagent for Potassium Based on Crown Ether Complex Formation

Abstract

The extraction study of alkali metal ions was made with a new type of crown ether, 4′-picrylaminobenzo-15-crown-5 (HL). Upon dissociation in alkaline medium orange-colored HL gives blood-red anion, L^?, and extracts selectively K⁺ (and to a lesser extent Rb⁺) ion into chloroform as a colored complex of composition ML·HL. A colorimetric determination of 10 - 400 ppm K⁺ in the presence of < 2000 ppm Na⁺ was possible using this new crown ether reagent.     

A Novel Type of Crown Ether‐Containing Metal Ions Optical Sensors Based on Polymer‐Stabilized Cholesteric Liquid Crystalline Films

For the first time, the films based on polymer‐stabilized cholesteric composites containing crown ether fragments with the optical properties sensitive to the complexation with potassium and barium ions were obtained. The complexation with these ions leads to blue spectral shift of the selective light reflection of planar cholesteric texture of composite films. Peculiarities of spectral changes and kinetics of selective light reflection shift were studied. The proposed approach can be used for the creation of the effective and selective sensor materials for different ions or groups of ions.     

Integrative Self‐Sorting: One‐Pot Synthesis of a Hetero[4]rotaxane from a Daisy‐Chain‐Containing Hetero[4]pseudorotaxane

The structural complexity of mechanically interlocked molecules are very attractive to chemists owing to the challenges they present. In this article, novel mechanically interlocked molecules with a daisy‐chain‐containing hetero[4]rotaxane motif were efficiently synthesized. In addition, a novel integrative self‐sorting strategy is demonstrated, involving an ABB‐type (A for host, dibenzo‐24‐crown‐8 (DB24C8), and B for guest, ammonium salt sites) monomer and a macrocycle host, benzo‐21‐crown‐7 (B21C7), in which the assembled species in hydrogen‐bonding‐supported solvent only includes a novel daisy‐chain‐containing hetero[4]pseudorotaxane. The found self‐sorting process involves the integrative recognition between B21C7 macrocycles and carefully designed components simultaneously containing two types of secondary ammonium ions and a host molecule, DB24C8 crown ether. The self‐sorting strategy is integrative to undertake self‐recognition behavior to form one single species of pseudorotaxane compared with the previous report. This self‐sorting system can be used for the efficient one‐pot synthesis of a daisy‐chain‐containing hetero[4]rotaxane in a good yield. The structure of hetero[4]rotaxane was confirmed by ¹H NMR spectroscopy and high‐resolution electrospray ionization (HR‐ESI) mass spectrometry.     

A Supermolecule Assembled by Sodium Cation,Crown Ether and α‐Dawson Heteropolyanion

The supermolecular based on sodium molybdate(VI) and sulfate, dibenzo‐18‐crown‐6 was synthesized in acetonitrile and characterized by elemental analysis, IR, ¹H NMR, single crystal X‐ray diffraction, indicating that it contains [S₂Mo₁₈O₆₂]⁴⁺ and [Na(DB18C6)(H₂O)]⁺, where each sodium ion is deviated from the plane defined by the oxygen atoms in the corresponding crown ether. The compound crystallizes in the monoclinic space group C2/c with a=3.29332(10) nm, b=1.90917(6) nm, c=2.63132(7) nm, β=121.6630(10)°, V=14081.8(7) nm³, Z=8, T=293(2) K, and R₁ (wR₂)=0.0177 (0.1525). The compound exhibits a novel organic‐inorganic structure, in which the crown ether‐sodium complexes are coordinated to the terminal oxygen atoms of Mo₁₈O₅₄ and the oxygen atoms of water molecule.     

Two—dimensional Network Crown Ether Complex.Synthesis and Crystal Structure of 18—Crown—6 Complex：[K（18—C—6）]2[Cd—（nmt）2]

The novel complex [K(18-C-6)]2[Cd(mnt)2][18-C-6-18-crown-6,nmt=1,2-dicyanoethene-1,2-dithiolate,C2S2-(CN)2^2-] was synthesized and characterized by elemental analysis,IR spectrum and X-ray diffraction analysis.The complex displays two-dimensional network structure of [K(18-C-6)] complex segments and [Cd(nmt)2] complex segment bridged by S-K-S,S-K-N and N-K-N interactions between adjacent[K(18-C-6)] and [Cd(mnt)2]units.     

Nitrite‐Templated Synthesis of Lanthanide‐Containing [2]Rotaxanes for Anion Sensing

The first anion‐templated synthesis of a lanthanide‐containing interlocked molecule is demonstrated by utilizing a nitrite anion to template initial pseudorotaxane formation. Subsequent stoppering of the interpenetrated assembly allows for the preparation of a lanthanide‐functionalized [2]rotaxane in high yield. Following removal of the nitrite anion template, the europium [2]rotaxane host is demonstrated to recognize and sense fluoride selectively.     

Application of Crown Ether to Chemical Analysis. III. Extraction of Amines with Crown Ether

Abstract

The protonated amines were extracted with crown ether as the picrate into organic solvent. The overall extraction constants(Kex) for the 1 : 1 : 1 complexes, AHLP, of 18-crown-6 with protonated amines and picrate between 1,2-dichloroethane and water have been determined at 25°C. The extractability of complexes decreased in the sequence: primary amines > secondary amines, which indicated that the type of amine was a most important factor. The log Kex values were determined to be 6.6, 7.6, 7.9, 8.3, 9.6, 2.5 and 3.8 for tert-butylamine, ethylamine, n-butylamine, sec-butylamine, n-hexylamine, diethylamine and di-n-propylamine respectively.     

萘二酰亚胺[3]轮烷的设计合成及发光性能研究

设计合成了以乙氧基柱[5]芳烃为环状分子,萘二酰亚胺衍生物为线性分子的[3]轮烷（[3]R和[3]R'）.其分离产率分别达到45%和62%.利用核磁氢谱和碳谱、二维旋转Overhause波谱（ROESY）以及高分辨质谱等对[3]R和[3]R'的轮烷结构进行了详细表征,并系统研究了轮烷分子的紫外吸收和荧光光谱.由于两侧大体积的乙氧基柱[5]芳烃阻止了[3]轮烷在高浓度下芳香环的过密堆积,使得[3]R和[3]R'即使在固体状态下都可以发射明亮的红色荧光.推测该轮烷分子在发光材料、光电器件等方面有潜在应用,同时本研究也对高效固体发光分子的制备提供了新思路.     

Rotaxanes Synthesized Through Sodium‐Ion‐Templated Clipping of Macrocycles Around Nonconjugated Amide and Urea Functionalities

A single urea or amide functionality in a dumbbell‐shaped guest can be “clipped” by a macrocycle generated from a diamine and a dialdehyde through the templating effect of a Na⁺ ion (see scheme). The resulting imine‐containing rotaxanes can then be reduced to allow isolation of stable amine‐based rotaxanes.     

双羟甲基冠醚的合成

以甘油单三苯甲基醚为原料,分别与乙二醇,二甘醇和三甘醇的双对甲苯磺酸酯经三步反应,合成得到双羟甲基－１２－冠－４,双羟甲基－１５－冠－５,双羟甲基－１８－冠－６,双羟甲基－２１－冠－７和双羟甲基－２４－冠－８等一系列新型醚化合物。     

Calix[4]arenes Bridged with Two Different Crown Ether Loops: Influence of Crown Size on Metal Ion Recognition

A series of calix[4]arene-bis-crownethers were synthesized in a fixed 1,3-alternateconformation with good yields by the reaction of amonocyclic calixcrown ether with multi-ethyleneglycoldi-p-toluenesulfonate in the presence of cesiumcarbonate. In the preparation of the monocycliccalixcrown ethers (1 and 2), the use ofpotassium carbonate as a base provided the best yieldregardless of the template concept. In two phaseextraction and competitive transport experiments forligand-metal complexation, calix[4]arene biscrown(5) provided the best selectivity for potassiumion. When a calixbiscrown ether (4) bearingdifferent sized crown ether loops coordinates to K⁺and Cs⁺, respectively, the changes of peak splittingpatterns and chemical shift on ¹H NMR spectra aredependent on the complexed metal ion species.     

Induced Near-Infrared Emission and Controlled Photooxidation based on Sulfonated Crown Ether in Water

Regulation of physio-chemical properties and reaction activities via noncovalent methodology has become one of increasingly significant topics in supramolecular chemistry and showed inventive applications in miscellaneous fields. Herein, we demonstrate that sulfonated crown ether can form very stable host-guest complexes with a series of push-pull-type photosensitizers, eventually leading to the dramatic fluorescence enhancement in visible and near-infrared regions. Meanwhile, severe suppression in singlet oxygen (¹O₂) production is found, mainly due to the higher energy barriers between the excited single and triple states upon host-guest complexation. Moreover, such complexation-induced tuneable ¹O₂ generation systems has been utilized in adjusting the photochemical oxidation reactions of polycyclic aromatic hydrocarbons (anthracene) and sulfides ((methylthio)benzene) in water. This supramolecularly controlled photooxidation based on the selective molecular binding of crown ether with photosensitizers may provide a feasible and applicable strategy for monitoring and modulating many photocatalysis processes in aqueous phase.     

由(+)-2-氨基丁醇合成氮杂手性冠醚

手性冠醚由于具有手性识别和不对称催化有机反应的性质而受到人们的重视,有关它们的合成及性质,已很多论述。氮杂冠醚则是合成穴醚、双冠醚、套索冠醚(LariatEther)等的重要中间体,也可与高分子材料(高分子载体或高分子基质)连接,用于有机化合物的色谱分离。氮杂手性冠醚兼备手性和氮杂冠醚两种特性,而可能具有广泛的用途。