Resorcinarene supramolecular organocatalyst for functionalized 1-tetralone synthesis in aqueous medium

An efficient, straightforward and environmentally benign process has been developed for the synthesis of fluorenone and 1-tetralone derivatives using cyclic 1,3-dione, malononitrile and dialkylacetylenedicarboxylate as starting materials in aqueous medium. The reaction is favoured in presence of resorcin[4]arene which is effective as a reusable organocatalyst. The catalyst has been easily synthesized and characterized by ¹H, ¹³C NMR, IR, XRD and HRMS analyses. Resorcin[4]arene afforded the resulted products in a shorter time and in good yields. The recyclability of the catalyst was established up to 6th cycle by FT-IR and SEM images.     

阻抑-褪色光度法测定痕量间苯二酚

在NH3 NH4Cl介质中 ,间苯二酚能阻抑Fe(Ⅲ )为催化剂 ,邻菲罗啉为活化剂的过氧化氢氧化甲酚红的褪色反应。研究了该反应的最佳条件和动力学参数。建立了一种测定痕量间苯二酚的新方法。方法检出限为 3 5× 1 0 - 4 g·L- 1 ,测定范围为 0 .30mg/L～ 7.0mg/L ,方法可用于废水中间苯二酚的测定     

Spectrometric Study of the Size Discrimination of Quaternary Ammonium Cations by Tetracyanoresorcin[4]arene

The inclusion complexes of tetracyanoresorcin[4]arene with six quaternary ammonium cations—biologically important acetylcholine and choline, tetramethyl ammonium, tetraethyl ammonium, tetrapropyl ammonium and tetrabutyl ammonium—were studied by means of electrospray ionization mass, fluorescence and NMR spectrometries. The results indicate that tetracyanoresorcin[4]arene shows high affinity toward these ammoniums and is capable of recognizing their sizes.

Spectrometric evidences for the size discrimination of quaternary ammonium cations by tetracyanoresorcin[4]arene are preseneted.     

Flow Injection Analysis of Mixtures of Dopamine,Adrenaline and Ephedrine in Human Biofluids Using Stabilized after Storage in Air Lipid Membranes with a Novel Incorporated Resorcin[4]arene Receptor

This work describes a technique for the rapid, selective and sensitive electrochemical flow injection analysis of mixtures of the stimulating compounds adrenaline, dopamine, and ephedrine using stabilized after storage in air bilayer lipid membranes (BLMs) with incorporated resorcin[4]arene receptor. Injections of the stimulating compounds were made into flowing streams of a carrier electrolyte solution and a transient current signal, with duration of seconds, reproducibly appeared in less than two min after exposure of the lipid membranes to the compounds. The magnitude of this signal was linearly related to the concentration of the compound, which could be determined at micromolar levels. Repetitive cycles of injection of stimulating compounds have shown no signal degradation during each cycle (30 sequential injections). The time of appearance of the transient response was different for each stimulating compound and increased in the order of adrenaline, dopamine and ephedrine. The difference in time of response has allowed selective detection and analysis of these compounds in mixtures. The investigation of the effect of potent interferences included a wide range of compounds usually found in human biofluids, as well as proteins and lipids. The results showed that only proteins (most common in lipid film based biosensors) pose a problem that can be eliminated by modulation of the carrier solution to flow rates that do not allow adsorption of these compounds in the lipid films. The technique was applied in human urine samples.     

吸光度比值-导数光谱新方法及其在两组分同时测定中的应用

本文叙述了吸光度比值－导数光谱新方法的原理,研究了在普通分光光度计上用计算法完成吸光度比值导数运算、同时测定苯酚和间苯二酚含量的实验方法,取得了较为满意的结果。苯酚的回收率为９９．４％～１０４．２％（ｎ＝２５,ＲＳＤ＝１．１％）,间苯二酚的回收率为９７．１％～１０２．８％（ｎ＝２５,ＲＳＤ＝１．６％）。     

Highly Strained Oxygen-Doped Chiral Molecular Belts of the Zigzag-Type with Strong Circularly Polarized Luminescence

Herein we report a two-directional cyclization strategy for the synthesis of highly strained depth-expanded oxygen-doped chiral molecular belts of the zigzag-type. From the easily accessible resorcin[4]arenes, an unprecedented cyclization cascade generating fused 2,3-dihydro-1H-phenalenes has been developed to access expanded molecular belts. Stitching up the fjords through intramolecular nucleophilic aromatic substitution and ring-closing olefin metathesis reactions furnished a highly strained O-doped C₂-symmetric belt. The enantiomers of the acquired compounds exhibited excellent chiroptical properties. The calculated parallelly aligned electric ( μ ) and magnetic ( m ) transition dipole moments are translated to the high dissymmetry factor (|g_lum| up to 0.022). This study provides not only an appealing and useful strategy for the synthesis of strained molecular belts but also a new paradigm for the fabrication of belt-derived chiroptical materials with high CPL activities.     

Polyoxometalate-Incorporated CuI-Resorcin[4]arene Metal-Organic Complexes as Heterogeneous Catalysts for Catalytic Oxidation of Mustard Gas Simulant

Exploring efficient heterogeneous catalysts for catalytic oxidation of chemical warfare agents (CWAs) is highly desired. As a class of discrete anionic metal oxide clusters, polyoxometalates (POMs) provide abundant catalytic active sites, thus resulting their rich redox properties. Here, a family of known POM-incorporated Cu^I-resorcin[4]arene metal-organic complexes, namely, [Cu₄(TPTR4A)₂][PW₁₂O₄₀](OH) ⋅ 0.5DMA ⋅ 5H₂O ( Cu - PW ), [Cu₄(TPTR4 A)₂][PMo₁₂O₄₀](OH) ⋅ 2DMA ⋅ H₂O ( Cu - PMo ) and [Cu₄(TPTR4A)₂][SiW₁₂O₄₀] ⋅ 2.5DMA ( Cu - SiW ) were utilized as catalysts to promote the oxidation of 2-chloroethyl ethyl sulfide (CEES). Strikingly, compared to the novel compound [Cu₃Cl₆(TPTR4A)(DMA)] ⋅ CH₃CH₂OH (defined as Cu - T ), the three complexes exhibited excellent stability, indicating that the integration of POMs and metal–organic units could improve the stability of the compounds. Moreover, Cu - PMo and Cu - PW showed higher activities for the catalytic oxidation of CEES to CEESO with selectivities both of 99 %.     

Tetrathiafulvalene (TTF)‐Bridged Resorcin[4]arene Cavitands: Towards New Electrochemical Molecular Switches

We report the synthesis of novel resorcin[4]arene‐based cavitands featuring two extended bridges consisting of quinoxaline‐fused TTF (tetrathiafulvalene) moieties. In the neutral form, these cavitands were expected to adopt the vase form, whereas, upon oxidation, the open kite geometry should be preferred due to Coulombic repulsion between the two TTF radical cations (Scheme 2). The key step in the preparation of these novel molecular switches was the P(OEt)₃‐mediated coupling between a macrocyclic bis(1,3‐dithiol‐2‐thione) and 2 equiv. of a suitable 1,3‐dithiol‐2‐one. Following the successful application of this strategy to the preparation of mono‐TTF‐cavitand 3 (Scheme 3), the synthesis of the bis‐TTF derivatives 2 (Scheme 4) and 19 (Scheme 5) was pursued; however, the target compounds could not be isolated due to their insolubility. Upon decorating both the octol bowl and the TTF cavity rims with long alkyl chains, the soluble bis‐TTF cavitand 23 was finally obtained, besides a minor amount of the novel cage compound 25a featuring a highly distorted TTF bridge (Scheme 6). In contrast to 25a , the deep cavitand 23 undergoes reversible vase → kite switching upon lowering the temperature from 293 to 193 K (Fig. 1). Electrochemical studies by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) provided preliminary evidence for successful vase → kite switching of 23 induced by the oxidation of the TTF cavity walls.     

Biosensors for the Rapid Repetitive Detection of Adrenaline Using Stabilized Bilayer Lipid Membranes (BLMs) with Incorporated Calix[4]resorcinarene Receptor

This work uses lipid film based biosensors with incorporated calix[4]resorcinarene receptor (lipophilic macrocyclic host molecule) for the rapid electrochemical detection of adrenaline. Freely‐suspended and metal supported BLMs (composed of egg phosphatidylcholine (PC) and 35% (w/w) dipalmitoyl phosphatidic acid) modified with the resorcin[4]arene receptor were used as one shot sensors to rapidly detect this catecholamine. The interactions of this compound with freely‐suspended BLMs were found to be electrochemically transduced in the form of a transient current signal with duration of seconds, which reproducibly appeared about 14 s after exposure of the membranes to adrenaline. The response time for these BLMs without incorporated receptor for adrenaline was about 1.5 min. The magnitude of the transient current signal was related to the concentration of adrenaline in bulk solution in the micromolar range. Differential scanning calorimetric (DSC) experiments were performed to explore the mechanism of interactions of BLMs with incorporated receptor with adrenaline. The interactions of adrenaline with surface‐stabilized bilayer lipid membranes (sBLMs) with incorporated receptor produced electrochemical ion current increases, which reproducibly appeared within a few seconds after exposure of the membranes to the stimulant. The use of the receptor in sBLMs increased the sensitivity of the method 6‐fold. The current signal increases were related to the concentration of adrenaline in bulk solution in the micromolar range. Stabilized lipid membranes formed by polymerization on glass fiber microfilters were used as practical chemical biosensors for the rapid detection of adrenaline. The interactions of polymerized lipid films with adrenaline were also found to provide transient current signals similar to those of freely‐suspended BLMs. The magnitude of the transient current signal was also related to the concentration of the stimulating agent in bulk solution in the micromolar range and these stabilized lipid films can be used again after storage in air. No interferences from ascorbic acid were noticed because of the negatively charged lipids in membranes. The effect of other compounds such as proteins and other compounds closely related to adrenaline was also investigated. Results of recovery experiments using human urine have shown recoveries ranged between 94 to 105%, which shows no interferences from matrix effects due to the presence of urine constituents. The present sensor based on stabilized lipid films can be used for the rapid repetitive detection of this pharmaceutical substance and keep prospects for the selective determination of catecholamines in biofluids.