Upper-rim-modified thioether thiacalix[4]arene used for liquid-liquid extraction of Au(Ⅲ)and Pd(Ⅱ)in hydrochloric acid medium

Gold(Au)and palladium(Pd)play an increasing role in the production and human life;Therefore,it is of great significance to study their recovery.A 5,11,17,23-tetra-ethylthio-25,26,27,28-tetra-hydroxyl thiacalix[4]arene(TCAET)was synthesized specifically for the capture of Au(Ⅲ)and Pd(Ⅱ)from HCl medium by liquid-liquid extraction.In a 0.1 mol·L^(-1)HCl medium,the transfer of Au(Ⅲ)and Pd(Ⅱ)from the aqueous phase to the organic phase was highly efficient,with a transfer ratio of 100%for Au(Ⅲ)and 98%for Pd(Ⅱ).Furthermore,the extraction equilibrium time for Au(Ⅲ)was just 5 min.Job's method data demonstrated that TCAET formed complexes with Au(Ⅲ)and Pd(Ⅱ)in a ratio of 2:3 and 1:1,respectively,during the extraction process.TCAET showed high selectivity toward Pd(Ⅱ)and Au(Ⅲ)over other competing metal ions.Moreover,both Au(Ⅲ)and Pd(Ⅱ)could be successfully stripped from the loaded organic phases with a 1.0 mol·L^(-1)thiourea in 0.5 mol·L^(-1)HCl and 0.5 mol·L^(-1)thiourea in 0.5 mol·L^(-1)HCl,respectively.Results obtained from five consecutive extraction-stripping cycles showed good reusability of TCAET toward Au(Ⅲ)and Pd(Ⅱ)recovery.The conclusion can provide a certain reference for thiacalixarene in the recovery of precious metal species.

Langmuir-Schaefer Film Investigation and Density Functional Theory Band Gap Calculations of Calix[n]arene-Para-Aminobenzoic Acid for Drug Nanosensor Application

Calix[n]arenes was utilized to detect PABA,the primary sunscreen component.This study investigates the interaction of calix[4]arene(C4),calix[6]arene(C6),and PABA using the Langmuir method and first-principle density functional theory(DFT).Using the Langmuir-Schaefer(LS)technique,an ultrathin film composed of calix[n]arenes and their complexes with PABA was deposited on various substrates.Based on the Langmuir study,the PABA molecule was bonded to the lower rims of both C4 and C6 with the host-guest ratio of 1:1.All of the LS films formed were then characterized by ultravioletvisible spectroscopy(UV-Vis),Fourier-transform infrared spectroscopy(FTIR)and carbon,hydrogen,nitrogen,sulfur elemental analyzer(CHNS).The band gap reduction obtained in the DFT study denotes the charge transfer interaction with promising reactivity between the calix[n]arenes and PABA.The sensing of PABA by C4 and C6 is successful based on the formation of bonding between them due to the hosts’effective trapping capacity.The outcomes of this study could be applied to drug delivery systems for future pharmaceutical and medical applications.

Enhanced hydrodeoxygenation of lignin-derived anisole to arenes catalyzed by Mn-doped Cu/Al_(2)O_(3)

Lignin is a renewable carbon resource to produce arenes due to its abundant aromatic structures.For the liquid-phase hydrodeoxygenation(HDO)based on metallic catalysts,the preservation of aromatic rings in lignin or its derivatives remains a challenge.Herein,we synthesized Mndoped Cu/Al_(2)O_(3) catalysts from layered double hydroxides(LDHs)for liquid-phase HDO of lignin-derived anisole.Mn doping significantly enhanced the selective deoxygenation of anisole to arenes and inhibited the saturated hydrogenation on Cu/Al_(2)O_(3).With Mn doping increasing,the surface of Cu particles was modified with MnO_(x) along with enhanced generation of oxygen vacancies(Ov).The evolution of active sites structure led to a controllable adsorption geometry of anisole,which was beneficial for increasing arenes selectivity.As a result,the arenes selectivity obtained on 4Cu/8Mn4AlO_(x) was increased to be more than 6 folds of that value on 4Cu/4Al_(2)O_(3) over the synergistic sites between metal Cu and Ov generated on MnO_(x).

Synthesis and Structure of a Host-Guest Inclusion System between C-propyl-o-toluidine-methyl-resorcin[4]arene and Ethanol Solvate

Tetra-bromo-methyl-resorcin[4]arene cavitands were synthesized and C-2 position amine functionalized to obtain C-propyl-o-toluidine-methyl-resorcin[4]arene cavitand 4, and the crystal containing one solvate molecule of ethanol was obtained in a dichloromethane-ethanol solvent system, its structure crystallized in the monoclinic space group P21/n, with a = 12.521(3) Å, b = 21.738(6) Å, c = 25.353(6) Å, α = 90˚, β = 102.372(4)˚, γ = 90˚, and Z = 4. The compound was determined by single-crystal X-ray diffraction and characterized by 1H NMR, FT-IR and elemental analyses.

Preparation and Characterization of Silica Modified with Calix[4]arene Derivatives

Three new silica gel modified with calix[4]arene derivatives （p-tert-butyl-calix[4]arene （PC4）, calix[4]arene （C4） and calix[4]arene sulfonate （C4S）） have been prepared via modification of activated silica gel with toluene 2,4-di-iso-cyanate （TDI） as linker in tow step. The modified silica were characterized by fourier transform infrared spectroscopy （FT1R）, thermal analysis （TGA） and elemental analysis. The FTIR spectra and TGA analysis verified that the calix[4]arene derivates are covalent attached to the silica. Scanning electron microscope SEM and Brunauer-Emmett-Teller BET analysis have been done to get information about the sample＇s surface shape and area. SEM and BET analysis reveal that the modified silica are in the range of microporous adsorbent.

基于ARENE软件的SVC仿真研究

基于ARENE软件 ,阐述了SVC进行无功补偿的工作原理 ,说明了SVC系统设计的内容方法。并以具体系统为例 ,对SVC进行线路补偿的动态特性作了仿真分析 。

Calix[4]arene Polyaza Derivatives: Novel Effective Neutral Receptors for Cations and α-Amino Acids

Introduction Calixarenes are one of the most important supra- molecular building blocks, which can be modified by introducing different functional and/or structural groups to create a specific interaction between the host and the target molecules, such as metal cations and small organic molecules. In particular, the recognition of amino acids is an interesting theme in biomimetic chemistry.

STUDIES ON CALIXARENES I THE CNDO/2 CALCULATION OF EQUILIBRIUM MOLECULAR GEOMETRY OF CALIX[4]ARENE IN CONE CONFORMATION

The equilibrium molecular geometry of 25, 26, 27. 28-tetrahydroxycalix[4]arene in cone cowtrmation was calculated by a CNDO/2 method based on the standard geometrical models. The results are in good agreement with those obtained from X-ray analysis.

Synthesis and Complexation Properties of Novel Biscalixarene Composed of Calix[4]arene and Thiacalix[4]arene Subunits

The first example of biscalixarene composed of calix[4]arene and thiacalix[4]arene subunits 3 was facilely synthesized and showed good complexation properties for metal cations and zwitterionic α-amino acids.

Phosphate Doubly Capped Tetrahomodioxacalix[6]arene

A bisphosphate-bridged tetrahomodioxacalix[6]arene with a C2v symmetry at the ambient temperature was obtained by the reaction of tetrahomodioxacalix[6]arene with POCl3.

An Interesting Approach to Bis-calix[5]arene Analogue from Calix[6]arene

By 1,4-bridging of p-tert-butylcalix [6] arene with 2,6-bis (bromomethyl)-4-methyl- anisole, a new type of bis-calix [5] arene analogue was obtained in high yield..

Synthesis and Properties of Double Calix[4]arene Derivatives Linked by Schiff-base in the Lower Rim

25,27-bis-(2-aminoethoxy)-p-tert-butylcalix[4]arene was linked to double calix[4]arene derivatives by the Schiff-base moiety in its lower rim. They behave strong ability to complex with Ph2+, Cu2+ and Co2+.

Synthesis and Crystal Structure of Calix[4]arene Bearing a 1,8-Bis(propoxy)anthracene-9,10-dione

The title complex （C50H44C14O8） was synthesized and structurally determined by single-crystal X-ray diffraction method. It crystallizes in monoclinic, space group P21/n with a = 19.7768（4）, b =10.2085（2）, c = 21.2721（4）A,β= 97.153（1）°, V = 4261.23（14）A^3, Z = 4, Mr = 914.65, F（000） = 1904, Dc = 1.426 g/cm^3,μ = 0.336, the final R = 0.0550 and wR = 0.1647. The compound was structurally characterized by IR and ^1H NMR. The molecules are stacked through C-H...π interactions and intermolecular C-H...O hydrogen bonds.

Ruthenium nanoparticles supported on mesoporous MCM-41 as an efficient and reusable catalyst for selective oxidation of arenes under ultrasound irradiation

Mesoporous MCM-41 was used as a support for the uniform dispersion of ruthenium nanoparticles having an average particle size of 5 nm.The obtained nanocomposite,MCM-41-Ru,was characterized using inductively coupled plasma,transmission electron microscopy,energy dispersive X-ray analysis,X-ray diffraction,and BET surface area measurements.The material was employed as an efficient and recyclable catalyst in the ultrasound-assisted oxidation of arenes.It was observed that ultrasound irradiation in combination with KBrO3 as the oxidant,in the presence of MCM-41-Ru nanoparticles,accelerates the oxidation reaction to afford the desired products in good yields.The recovered catalyst retained activity for successive runs,with a continuous change in the nature of its active sites.

Separation of Salbutamol by Nano-baskets of Calix[4]arene Bearing Sulfonyl-carboxamides in Partial-cone Conformation

Salbutamol,which increases the muscle mass and decreases the adipose tissue,is misused as nutrient repartitioning agent in the livestock.The novelty of this work is the determination of salbutamol in the livestock meat via new bonded-phases bearing eight derivatives of p-tert-calix[4]arene in partial-cone conformation.The new synthesized bonded-phases were characterized and optimized.The bonding interactions of solute and stationary-phases were examined and the main interactions were reported.The salbutamol levels in six samples of livestock meat were analyzed and the results reveal that for the best bonded-phases,the limit of detection（LOD） and limit of quantitation（LOQ） were 0.02 and 0.06 μg/mL,respectively.

Synthesis of Bis-substituted Calix[4]arenes and Mechanism of Substituents Effect on K^+ and Hg^(2+) Ions Transports through Liquid Membrane

New calix[4]arene derivatives containing nitro,amino and benzoyl in the upper and lower rims of molecule were successfully synthesized.Their effectiveness towards K+ and Hg2+ across bubbling liquid membrane(BLM) was examined.For K+ ion transfer,preserving phenolic hydroxyl in the lower rim of calix[4]arene could enhance its transport ability.When benzoyl replaced phenolic hydroxyl,the transport would fall off,because benzoyl caused steric hindrance on the K+ transfer.The study also revealed that the group having the electron-withdrawing conjugative effect on phenolic hydroxyl,-NO2 in the upper rim of calix[4]arene,made transport ability of calix[4]arene fall off.On the contrary,-NH2 that had electron-repulsive conjugative effect enhanced the transport ability of the compound.For Hg2+ ion,only -NH2 in the upper rim of calix[4]arenes had high affinity for it and contributed to Hg2+ transfer.Transport amount of Hg2+ ion increased with increasing calix[4]arene5 concentration and ΔpH in BLM.

A New Efficient Synthesis of p-Nitrocalix[4]arene

A new efficient synthesis of p-nitrocalix[4]arene from calix[4]arene by using nitrogen dioxide is described. The compound is an useful intermediates for the introduction of other functional groups to obtain N containing substituted calix[4]arene. The reaction mechanism is briefly discussed.

Synthesis of Schiff Base Calix[4]arene Crowns

This letter reports the synthesis of Schiff base calix[4]arene crowns containing m-xylylene phenol subunit, in which calix[4]arene Schiff base crowns 2a, 2b and 2c were formed by 1:1 condensation of calix[4]arene diamine 1 with dialdehydes (2, 6-diformyl-4-chlorophenol 3a, 2, 6-diformyl-4-methylphenol 3b, 2, 6-diformyl-4-tert-butylphenol 3c) under high dilute condition in refluxing anhydrous ethanol in 65-70% yield.

Iodine catalyzed efficient synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride under solvent-free conditions

Synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride in the presence of a catalytic amount of iodine at room temperature under solvent-free conditions is described. Mild reaction conditions, easy workup, high yield, and easily available catalyst are important features of this method.

Synthesis of Calix[4] arene Thia Derivative and Extraction Effect of Substituents on Mercury( Ⅱ) and Lead( Ⅱ)

Calix[4]arene derivatives have been reported to possess high selectivity for metal ions.In order to analyze the extraction effect of substituents on Hg^(2+)and Pb^(2+),calix[4]arene derivatives containing hydroxyl,bromoethoxy and 1,11-dioxa-4,8-dithiahendecene were successfully synthesized,with their extraction effectiveness towards Hg^(2+)and Pb^(2+)were evaluated respectively.The results indicated that the phenolic hydroxyl in calix[4]arene improved the extraction ability on Hg^(2+)by promoting the formation of the negative oxygen ions that could bind with Hg^(2+)by coordination and ionic bonds.The extraction ability of 5,17-dinitro-26,28-(1’,11’-dioxa-4’,8’-dithiahendecene)-calix[4]arene(calix[4]arene thia derivative)was improved slightly due to the better coordination capacity for metal ions after introduction of 1,11-dioxa-4,8-dithiahendecene,which was a chelate-binding centre.Regarding to Pb^(2+),only 1,11-dioxa-4,8-dithiahendecene on molecule contributed to extraction due to the coordination bond.Since the metal ion with higher charge-to-radius ratio could coordinate with one ligand more stably,Pb^(2+)with higher charge-to-radius ratio than Hg^(2+)was coordinated and extracted by the calix[4]arene thia derivative more easily.Furthermore,extraction rates of the calix[4]arene thia derivative on both ions(Hg^(2+)and Pb^(2+))increased with the increase of pH value in acidic aqueous system(pH<7).