Methacrylated calix[4]arene phosphonic acids as functionalized crosslinker for radical polymerization

We describe the synthesis of 5,11,17,23‐tetra‐tert‐butyl‐25,27‐dioxypropylphosphonic acid‐26,28‐dimethacryloyloxy‐calix [4]arene and 5,11,17,23‐tetra‐tert‐butyl‐25‐oxypropylphosphonic acid‐27‐hydroxy‐26,28‐dimethacryloyloxy‐calix[4]arene starting from para‐tert‐butyl‐calix[4]arene. The complete reaction was proved by matrix‐assisted laser desorption ionization time of flight mass spectrometry and nuclear magnetic resonance spectroscopy. The influence of these compounds on the kinetics of the radical polymerization of methyl methacrylate was shown by dilatometry. Furthermore, the adhesive properties of dental adhesives containing these calix[4]arene derivatives were investigated. Copyright © 2012 Society of Chemical Industry     

几种新型杯[4]芳烃衍生物的合成

以对叔丁基苯酚为起始原料,通过缩合、一步取代反应合成了对叔丁基杯[4]芳烃的衍生物,两步取代反应合成了对叔丁基杯[4]芳烃的衍生物。用FT-IR,^1HNMR,FAB-MS对产物的结构进行了表征。     

氨基硫脲基新型杯[4]芳烃衍生物的合成

通过1,3-环氧丙基杯[4]烃与硫代氨基脲开环反应,合成硫代氨基脲基杯[4]芳烃衍生物,研究了其对阳离子的吸附性能后发现,与其他氨基杯芳烃相比,该衍生物对铜离子的吸附性能较好,并且有很好的选择性。     

Synthesis,extraction, and adsorption properties of calix[4]arene‐poly(ethylene‐glycol) crosslinked polymer

Novel calix[4]arene‐poly(ethylene glycol) crosslinked polymer (CCP) has been synthesized by the polycondensation reaction between a p‐tert‐butylcalix[4]arene derivative and dihydroxyl capped poly(ethylene glycol) (DHPEG, M_n = 1000) catalyzed by neodymium tosylate. The hydrogel, consisted of 66.9% water and 33.1% CCP, can selectively extract aromatic organic molecules from aqueous solution according to the diameter of the guest molecules, which infers that the diameter of the calix[4]arene cavity is about 5.4 Å and the conformation of calix[4]arene units altered from cone conformation to 1,3‐alternate conformation during the polycondensation reaction. Furthermore, CCP can also adsorb naphthalene from gas phase, showing much higher capacity than active carbon does, which may have some potential applications in the field of separation and environment protection. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

杯芳烃／聚丙烯共混体系耐热氧性能的研究

合成了对叔丁基杯[4]、杯[6]、杯[8]芳烃,并用热重法和烘箱老化评价了共混体系的耐热氧性能。结果表明,杯芳烃能明显提高聚丙烯的耐热氧性能,其耐热氧能力为：对叔丁基杯[6]芳烃＞对叔丁基杯[4]＜2,6－二叔丁基－4－甲基苯酚。     

Adsorption of amino acid derivatives on calixarene carboxylic acid impregnated resins

Macrocyclic host molecules calixarene carboxylic acid derivatives are found to act as powerful extractants for biologically important amino compounds. A series of adsorbents were prepared from a methacrylate-based polymer Amberlite XAD-7 by impregnation with various calixarene derivatives, for adsorptive recovery of amino acid derivatives. The larger macrocycles calix[6]arene and calix[8]arene carboxylic acid derivatives were more effective for adsorption of amino acid derivatives on the impregnated resin than the calix[4]arene derivative. Since adsorption proceeds mainly via electrostatic interaction, the carboxylic acid groups introduced into the calixarene platform were important for adsorption of cationic amino acid derivatives. The adsorption selectivity for amino compounds using adsorbent impregnated with the calix[6]arene carboxylic acid derivative depends simply on the hydrophobicity of the adsorbates.     

Sulfonation of low‐density polyethylene and its impact on polymer properties

Sulfonation of polymers is of great importance for the packaging industry mainly due to its effect on the alteration of surface functionality of polymer films. In this study we customized liquid phase sulfonation of low‐density polyethylene (LDPE) swelling the polymer by using a combination of polar and nonpolar solvents. Swollen polymer was treated with sulfuric acid of varying concentrations with continuous mixing for in‐depth sulfonation of the polymer. Presence of cyclohexane and ethanol, as polar and nonpolar reagents, not only kept the batch under isothermal conditions but also homogenously influenced in‐depth functionalization of LDPE. The durability of the sulfonated polymer was determined by grinding the test samples 30 days after the reaction. Fourier transform‐infrared spectroscopy indicated presence of functional group moieties, which is also supported by increase of 5% and 1.35% in density and sulfur contents of the polymer, respectively. Contact angle measurements indicate 30° decrease in values of the sulfonated polymer which corresponds with decrease in carbon to hydrogen ratio (from 5.9 to 5.3) and increase in sulfur to carbon ratio (up to 0.0184) resulting from the sulfonation of the polymer. Differential scanning calorimetery results indicate almost linear reduction in the crystallinity of LDPE with an increase in acid concentration used for the sulfonation reaction. POLYM. ENG. SCI., 54:2522–2530, 2014. © 2013 Society of Plastics Engineers     

Molecular composites obtained by polyaniline synthesis in the presence of p‐octasulfonated calixarene macrocycle

Polyaniline (PANI) molecular composites were synthesized by chemical oxidative polymerization of the aniline and aniline dimer, N‐phenyl‐1,4‐phenylendiamine, in the presence of a macrocycle, calix[8]arene p‐octasulfonic acid (C8S), using ammonium peroxidisulfate as oxidant. The macrocycle has acted both as acid dopant and surfactant to obtain processable PANI‐ES. The PANI/calix[8]arene p‐octasulfonic acid composite was also obtained by a simple doping of PANI emeraldine base form with calix[8]arene sulfonic acid. The structure of materials was confirmed by Fourier transform infrared, UV–vis and nuclear magnetic resonance spectroscopy. All synthesized composite materials are amorphous and soluble in chloroform, dimethylsulfoxide, NMP, showing excellent solution‐processing properties combined with electrical conductivity. Cyclic voltammetry evidenced a good electroactivity for the composite films. Dielectric properties (dielectric constant and dielectric losses) were determined and are comparable with those of other PANI/ionic acid polymer composites. Preliminary studies have evidenced a high dielectric constant (10⁴ at 100 Hz) and electrical conductivity of 6 × 10^?3 S/cm for PANI composites. From sulfur elemental analysis of the PANI/calixarene, it results that the content in macrocycle is ～30% (weight). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Calixarenes 30. Calixquinones

Chlorine dioxide and thallium trifluoroacetate are shown to be useful reagents for the preparation of calixquinones. p-H-Calix[4]arene( 1a ),p-H-calix[5]arene ( 1b ), and p-H-calix[6]arene ( 1c ) are oxidized in modest yields by ClO₂ to the fully quinonoid compounds calix[4]tetraquinone ( 2a ), calix[5]pentaquinone ( 2b ), and calix[6]hexaquinone ( 2c ), respectively. Although Tl(OCOF₃)₃ is less effective for the oxidation of 1a-c , it proves to be the reagent of choice for converting partially etherified or esterified calixarenes carrying p-tert-butyl groups directly to partially quinonoid calixarenes. Thus, monosubstituted calix[4]arenes yield triquinones; disubstituted calix[4]arenes yield diquinones; trisubstituted calix[4]arenes yield monquinones; and tetrasubstituted calix[6]arenes yield diquinones. The structures of the calixquinones have been established by elemental analysis, ¹H NMR spectroscopy, mass spectroscopy, and in the case of 2c by X-ray crystallography. Since the starting materials are readily accessible, the calixquinones become easily available compounds for further study.     

Poly(ether ether sulfone)s and sulfonated poly(ether ether sulfone)s derived from functionalized 1,1‐diphenylethylene derivatives

Symmetrically disubstituted 1,1‐diphenylethylene derivatives, 1,1‐bis[4‐(t‐butyldimethylsiloxy)phenyl]ethylene and 1,1‐bis(4‐hydroxyphenyl)ethylene, were prepared by new synthesis methods and employed as functionalized monomers in the preparation of new poly(ether ether sulfone) derivatives, with the introduction of the 1,1‐diphenylethylene unit along the polymer backbone. A series of parent 1,1‐diphenylethylene based poly(ether ether sulfone)s were prepared via (a) the cesium fluoride catalysed polycondensation reactions of dihalogenated diaryl sulfones with silylated bisphenols and (b) the base catalysed aromatic nucleophilic substitution polycondensation reaction between aromatic dihalogenated diaryl sulfones with bisphenols. The post‐polymerization sulfonation reaction via the thiol‐ene addition reaction of the poly(ether ether sulfone) precursor containing the 1,1‐diphenylethylene unit along the backbone, with sodium 3‐mercapto‐1‐propane sulfonate, afforded well‐defined sulfonated poly(ether ether sulfone), with the alkyl sulfonate group introduced pendant to the polymer backbone. The organic compounds and different polymer derivatives were characterized by standard chromatography, spectroscopy, spectrometry, thermal analyses, microscopy and X‐ray diffraction measurements. © 2016 Society of Chemical Industry     

Calix[4]arene‐tetranitrone as crosslinker in dental composite materials

The synthesis of a functionalized calix[4]arene bearing 1,3‐dipolaric nitrone groups ( 5 ) has been carried out. The reaction of N‐methylhydroxylamine or N‐propylhydroxylamine with the carbonyl group of 5,11,7,23‐tetraformyl‐25,26,27,28‐tetraalkoxycalix[4]arene leads to calix[4]arenes bearing a nitrone function at each of the four para‐positions. Via 1,3‐dipolar cyclo‐addition of acrylic acid methyl ester with the nitrone functions of 5 , subsequently an upper rim‐substituted tetraisoxalidinecalix[4]arene is quantitatively synthesized. Further, the minimization of shrinkage of a dental filling depending on the amount of calix[4]arene‐tetranitrone is discussed. Copyright © 2011 Society of Chemical Industry     

Calix[n]arenes. IV. Interaction of tert-Butylcalix[n]arenes with Cyclic Amines

p-tert Butylcalix[n]arenes 1 and 2 react with the cyclic amines 3 – 8 , 10 by proton transfer forming so-called „exo-complexes”︁ between the ammonium and phenolate groups. As well endocyclic as exocyclic amino groups are reactive. The nitroxyl radical 9 does not react with 1 or 2 by the proton transfer reaction. These results demonstrate that an interaction between the nitrogen atom of HALS-compounds, esp. compound 10 , with calix[n]arene hydroxylgroups is possible, but an interaction between the corresponding nitroxyl radicals with calix[n]arene hydroxylgroups does not occur.     

Electrochemical oxidation of <Emphasis Type="Italic">p</Emphasis>-sulfonated calix[8]arene

The water-soluble p-sulfonated sodium salt of calix[8]arene (III) was synthesized. The product was characterized by FT-IR, NMR and UV–Vis spectra.Then the electrochemical behaviors of p-sulfonated sodium salt of calix[8]arene in NaAc+HAc (pH = 4) buffer solution was studied. In aqueous solution, p-sulfonated calix[8]arene can be oxidized when the potential is more than 0.7 V vs SCE. It was confirmed that the reaction was a two-electron irreversible electrochemical reaction. The transfer coefficient, α, was measured as 0.7. At 25°, the diffusion coefficient of p-sulfonated calix[8]arene was determined as 8.6 × 10⁻⁷ cm² s⁻¹. The diffusion activation energy of p-sulfonated calix[8]arene was 18.9 kJ mol⁻¹ at pH = 4.     

New polyisobutylene stars XI. Synthesis and characterization of allyl-telechelic octa-arm polyisobutylene stars

The synthesis and characterization of a novel star comprising eight allyl-terminated polyisobutylene (PIB) arms radiating from a calix[8]arene core is described. The synthesis was accomplished by a core-first method, by inducing the living polymerization of isobutylene (IB) by a suitably functionalized calix[8]arene initiator (1) in conjunction with BCl₃-TiCl₄ coinitiators, and terminating the growth of the living PIB^⊕ arms by allyltrimethylsilane. The relative concentrations of BCl₃ and TiCl₄ are critical for the synthesis of well-defined 8-arm stars. Characterization of the products (which included triple detector GPC studies and ¹H NMR spectroscopy) indicated quantitative allylation. A mechanism which summarizes the experimental observations is proposed. Received: 17 July 1997/Revised version: 11 September 1997/Accepted: 19 September 1997     

Synthesis and binding properties of polymeric calix[4]arene nitriles

Two new polymers containing pendant calix[4]arene units with nitrile functionalities at their lower rim have been synthesized via radical initiated reactions involving a vinylic monomer 6 {5,11,17,23-tetra-tert-butyl-25,26,27-tris(cyanomethoxy)-28-(2-acryloyloxy) ethoxycalix[4]arene} and with styrene. A five atom spacer group was incorporated between the bulky calixarene core and the acrylate moiety in order to minimize steric interactions which proved to impede the polymerization. The complexation studies were made by using liquid–liquid extraction procedures. It has been deduced from the observations that both polymers show a good selectivity towards Hg²⁺ like their precursor 5,11,17,23-tetra-tert-butyl-25,26,27-tricyanomethoxy-28-(2-hydroxy)ethoxycalix[4]arene 5, which supports their utility as adsorbents or potential candidate materials for fabricating membranes and sensors, which can separate or detect Hg²⁺ metal ions in a high selectivity.     

Synthesis of novel sulfonated polybenzimidazole and preparation of cross-linked membranes for fuel cell application

A novel sulfonated polybenzimidazole, sulfonated poly[2,2′-(p-oxydiphenylene)-5,5′-bibenzimidazole] (SOPBI), was successfully prepared by post-sulfonation reaction of the parent polymer, poly[2,2′-(p-oxydiphenylene)-5,5′-bibenzimidazole] (OPBI), using concentrated and fuming sulfuric acid as the sulfonating reagent at 80 °C, and the degree of sulfonation (DS) could be regulated by controlling the reaction conditions. No significant polymer degradation was observed in the post-sulfonation processes. Direct polymerization of 4,4′-dicarboxydiphenyl ether-2,2′-disulfonic acid disodium salt (DCDPEDS) and 3,3′-diaminobenzidine (DABz), however, resulted in insoluble gels either in polyphosphoric acid (PPA) or in phosphorus pentoxide/methanesulfonic acid (PPMA) in a ratio of 1:10 by weight reaction medium. The SOPBIs prepared by the post-sulfonation method showed good solubility in dimethyl sulfoxide (DMSO), high thermal stability, good film forming ability and excellent mechanical properties. Cross-linked SOPBI membranes were successfully prepared by thermal treatment of phosphoric acid-doped SOPBI membranes at 180 °C in vacuo for 20 h and the resulting cross-linked membranes showed much improved water stability and radical oxidative stability in comparison with the corresponding uncross-linked ones, while the proton conductivity did not change largely. Highly proton conductive (150 mS cm⁻¹, 120 °C in water) and water stable SOPBI membrane was developed.     

Novel linear molecular aggregation tethered by hydrogen-Bonded interaction within the crystalline calix[4]arene derivatives

Single crystals of two calix[4]arene derivatives, that is, 5,11,17,23-tetra-tert-butyl- 25,27-bis[2-[N-(3-methoxy-4-methoxy-benzylidene)-amino]ethoxy]-26,28- dihydroxy calix[4]arene (1) and 5,11,17,23-tetra-tert-butyl-25,27-bis[2-[3- pyridine carbonyl-amino]ethoxy]-26,28-dihydroxy calix[4]arene (2), were prepared and their crystal structures have been determined by X-ray crystallographic study. As compared with calix[4]arene derivative 1 possessing CN functional group, compound 2 bearing the NH group could form not only intermolecular hydrogen bonds between the hydrogen atom in NH group and the oxygen atom in CO of an adjacent calix[4]arene molecule, but also intramolecular hydrogen bonds between the N—H⋯OC moieties in solid state, giving a rare linear molecular aggregation.     

Mixed 8-oxyquinolinecalix[4]arene/phenanthroline receptors as luminescence sensors for zinc(II) ions

The luminescence behavior of bis-(8-oxyquinoline)calix[4]arene is practically centered on the quinoline chromophore, but involves efficient energy transfer from the calix[4]arene moiety. In the presence of Zn²⁺ ions, coordination of the quinoline groups is observed, leading to characteristic changes in the absorption, fluorescence and NMR spectra. Energy transfer from the calix[4]arene moiety is precluded by the coordination of the Zn²⁺ ions. In the resulting complex, a significant decrease in the emission quantum yields takes place. However, by incorporating an additional batho-phenanthroline ligand, a great emission enhancement has been detected, revealing the occurrence of synergistic effects in the bis-(8-oxyquinoline)calix[4]arene(batho-phenanthroline)zinc(II) complex.     

Novel Upper Rim Functionalizations of Calix[4]arenes using the Tscherniac-Einhorn Amidomethylation Reaction

A variety of novel upper rim functionalized calix-[4]arenes have been synthesized, using the Tscherniac-Einhorn amidomethylation reaction. Partially or fully alkylated calix [4]arenes bearing propyl or ethoxyethyl substituents could be easily condensed with various N-methylol-amides and -imides under mild conditions. The resulting methyl-acetamido- ( 4a , 4b , 7a ), methylchloroacetamido ( 4c , 4d , 7b , 7c , 9 methylphthalimido ( 4e , 4f , 4h )and methylchloroacetamido methylphthalimido functionalized calix[4]arenes ( 5 ) were obtained in yields varying from 30 till 97%. The amidomethylation reactions were proven to be independent of the conformation of the calix[4]arene.     

Thermal Behaviors of Bisazocalix[4]arene Derivatives

In this article, calix[4]arene (4) was prepared by debutylation and hydrolyses reacting from 25,27-dibenzoyl-26,28-dihydroxy-5,11,17,23-tetra(tert-butyl)calix[4]arene (2). Azocalix[4]arenes (6a-c) were coupled by linking 4-methoxy, 4-ethyl, and 4-nitroaniline to calix[4]arene (4) through a diazo-coupling reaction. Thermal behavior characteristics and decomposition routes of 25,26,27,28-tetrahydroxy-11,23-di(tert-butyl)-5,17-(p-substitue phenyl)azocalix[4]arene (6a-c) were investigated in air atmosphere by means of thermogravimetry (TG), differential thermogravimetry (DTG), and differential thermal analysis (DTA) analyses. It was found that the decomposition of all compounds complete with two exothermic stages which corresponded to removal of substitute groups (methoxy-, ethyl-, nitro-) and second stage rest of structure decomposition.