Synthesis and characterization of a novel organic–inorganic hybrid supramolecular recognition material and its selective adsorption for cesium

To separate Cs(I) from highly active liquid waste, a macroporous silica-based 25, 27-bis(iso-propyloxy)calix[4]arene-26,28-crown-6 (BiPCalix[4]C6) supramolecular recognition material, BiPCalix[4]C6/SiO₂–P, was synthesized and characterized by SEM, FT-IR, and TG-DSC. The adsorption properties of BiPCalix[4]C6/SiO₂–P and a macroporous polymer-based supramolecular recognition composite, BiPCalix[4]C6/XAD-7, were compared. It was found that BiPCalix[4]C6/SiO₂–P exhibited better adsorption ability and faster adsorption dynamics than BiPCalix[4]C6/XAD-7. The adsorption isotherm of Cs(I) onto BiPCalix[4]C6/SiO₂–P was studied at 298 K and it was well described by Langmuir isotherm model. The complex composition between BiPCalix[4]C6/SiO₂–P and Cs(I) was determined as 1:1 type by investigating the effect of the concentrations of BiPCalix[4]C6, Cs(I), and H⁺ on the adsorption. Meanwhile, the selectivity of BiPCalix[4]C6/SiO₂–P towards Na(I), K(I), Rb(I), Cs(I), Sr(II), Ba(II), Ru(III), Mo(VI), La(III), and Y(III) was investigated.     

Study on the Total Synthesis of Et 743 and its Analogues： Synthesis of a Tricyclic Intermediate and its 11-Epimer

The tricyclic compound 1, a key intermediate of the pentacyclic core of Et 743 and its analogues, was synthesized. Its 11-epimer was found as the product of racemization when BOP was used as the coupling agen4 but not when BOP-Cl used in the same reaction. The stereochemistry of both isomers was confirmed on basis of the ^1H NMR and NOE-difference spectra.     

Synthesis and characterization of a novel series of unsymmetrical porphyrins

A novel series of unsymmetrical porphyrins with aldehyde group at the terminal of the linkage which connected to meso-phenyl through acylamide bond have been synthesized and structurally characterized by IR,~1H NMR,MS,UV-vis,fluorescence.     

Synthesis of a New Cobalt (II) Complex and its Interaction with DNA

The interaction of metal complexes with DNA has been widely studied by differentmethods such as spectrophotometry, light scattering technique, fluorometry1-3. Manycomplexes such as Co(phen)2 ,Co(en)2 ,Fe(EDTA)2- etc.4,5 have been synthesized and 3+ 3+their effect on DNA has been studied in order to further explain the mechanism of genemutation, anti-cancer or cancer-induced reason and DNA targeted drugs. In this paper,a new cobalt complex was synth…     

Synthesis and curing of a novel amino-containing phthalonitrile derivative

A novel phthalonitrile derivative containing an amino group, 3,5-bis(3,4-dicyanophenoxy)aniline (CPA), was synthesized via a nucleophilic displacement of 4-nitrophthalonitrile and 5-aminoresorcinol hydrochloride. The structure of CPA was confirmed by Fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance (1H NMR). Thermal analysis performed on CPA revealed that the novel phthalonitrile derivative showed a self-promotion curing behavior and the resulting polymer exhibited outstanding heat-resistance.     

Studies on the Synthesis of a Natural Product—Piceatannol and its Analogs

Piceatannol,(E)-3,3′,4,5′-tetrahydroxy stilbene, a natural polyhydroxy stibene, possesses many biological activities, its synthesis has been reported. We designed another route of its synthesis, which can be controlled more easily. The synthetic product was characterized by elemental analysis,IR,MS and ^1H-NMR. Its analogs were synthesized by the similar method.     

Synthesis of a novel centipede-like copolymer of styrene and methyl methacrylate

A well-defined,A2B-type,centipede-like copolymer of styrene and methyl methacrylate(PS-PS-PMMA) was synthesized by the combination of living anionic polymerization and atom transfer radical polym-erization(ATRP) . The synthetic approach involves the coupling reaction of polystyrene(PS) backbone bearing 1,1-diphenylethene(DPE) pendant groups,produced by ATRP and Wittig reaction,with living polystyryllithium(PSLi) ,and subsequent polymerization of the resulting 1,1-diphenylmethyl anions with methy methacrylate. The centipede-like copolymer was characterized by 1H NMR,IR,SEC,SLS,and DSC measurements.     

Synthesis and characterization of novel polyimides based on thiazole-containing diamine

A new kind of aromatic diamine monomer containing thiazole unit,2-amino-5-(4-aminophenyl)-thiazole (AAPT),was synthesized in three steps,starting from 4-nitroacetophenone.A novel thiazole-containing polyimide was prepared via the polycondensation of AAPT with 6FDA by one-step method.The resulting polyimide exhibits excellent solubility,film-forming capability and high thermal resistance.     

Synthesis and photoreaction mechanism of a novel bifunctional photochromic compound

New functionalized spiroxazine containing azo group has been prepared and its photochromic mechanism has been investigated by laser induced time-resolved techniques.     

Studies on ketene and its derivatives—XIII: Synthesis of β-aminocrotonamide and the structure of its pyrolysed product

Reaction of diketene with an excess of ammonia gives β-aminocrotonamide (I), which on heating is transformed into β-(β′-aminocrotonylamino)crotonamide (IIb) which had been incorrectly assigned the structure 4-amino-3,4-dihyro-4,6-dimethyl-1H-2-pyridone-5-carbamide (IIa).^1,3 Hydrolysis of IIb with alkali gave 2,6-dimethyl-3H-4-pyrimidone (V) in a good yield. Structural assignments of IIb are described.     

Electrochemical characterization of cationic surfactants’ adsorption on a disturbed n-alkanethiolate self-assembled monolayer-modified polycrystalline gold electrode

The adsorption of cetyltrimethylammonium bromide (CTAB) on disturbed n-alkanethiolate self-assembled monolayers (SAMs) was investigated by electrochemical methods with potassium ferricyanide [K₃Fe(CN)₆] as a probe. Compared with the completely restrained signal at ordinary compact n-alkanethiolate SAMs, the electrochemical response of K₃Fe(CN)₆ at the disturbed n-alkanethiolate SAMs was partly restored and became progressively reversible in the presence of increasing concentrations of CTAB, which was employed to characterize the adsorption of cationic surfactants on hydrophobic SAMs. The effect of CTAB concentration on electrochemical impedance spectroscopy (EIS) plots indicated that CTAB experienced two different types of adsorptive behavior at the disturbed n-alkanethiolate SAMs: monomer adsorption at low concentrations below 1×10^–6 M and monolayer adsorption at CTAB concentrations above 1×10^–5 M. The adsorption of a series of cationic surfactants with similar structures to CTAB on disturbed n-alkanethiolate SAMs was also explored. These surfactants had similar adsorptive behavior and showed nearly linear adsorption characteristics with the length of their hydrophobic tails.     

Vitamin a analogues—II : Synthesis of 4-thia-vitamin a

The synthesis of 4-thia-vitamin A is described starting from 4-thia-ionone.¹ The stereo-chemical configurations of the intermediates obtained in the synthesis have been assigned by means of NMR spectrometry.² The UV absorption spectra of compounds of the 4-thia-vitamin A series show significant differences compared with the corresponding analogues of the vitamin A series. In biological growth test with chickens the all-trans 4-thia-vitamin A acetate shows ca. 5% of the activity of the all-trans vitamin A acetate.     

An investigation on a novel PDLC film's fabrication and its electro-optical properties

A polymer dispersed liquid crystal (PDLC) film that has good electro-optical properties is produced by the method of polymerized-induced phase separation. Based on the application foreground, its capability parameters, such as contrast ratio, work voltage, and visual angle, are characterized for the first time by a white light but not a fixed wavelength light. The results show the PDLC film has a low work-voltage of 20 V, more than 150° visual angle, high stability, and long lifetime. The differences between plastic and glass ITO-coated substrates of PDLC films are also studied in this paper. The plastic substrate has better property and will have a wider perspective especially in the portable, tender and folded display devices. Due to adjustable properties of film by electric field, PDLC has the potential application for display device, sensor, switch, grating, and new generation analytical apparatus.     

Synthesis of phosphinic acids on the basis of hypophosphites: IV. Synthesis of pseudo-γ-glutamylglycine and its enantiomers

A new method for construction of pseudopeptide molecules is proposed, exemplified by the synthesis of [3-amino-3-(hydroxycarbonyl)propyl][2-(hydroxycabonyl)ethyl]phosphinic acid (I) (pseudo--glutamylglycine), starting from ammonium hypophosphite. Enzymatic synthesis using immobilized penicillamidase allowed preparation of the enantiomers of acid I.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 8, 2004, pp. 1273–1278.Original Russian Text Copyright © 2004 by Ragulin.For communication III, see [1].This revised version was published online in April 2005 with a corrected cover date.     

Synthesis and surface activity of a novel heterodouble chained N-acyltaurate amphiphile

A novel double chained amphiphile,N-(α-4-hexylphenoxy)-lauroyltaurate(abbreviated as 10 6B-T),has been synthesized. The structures of main intermediate products and the title product were characterized by ~1H NMR.The new amphiphile shows high surface activity.The critical micelle concentration(cmc),which is 1.1×10~(-5)mol/L,is much lower than that of conventional double chained surfactants,such as sodium bis(2-ethylhexyl)sulfosuccinate(AOT).     

Synthesis and characterization of a novel amphiphilic copolymer containing β-cyclodextrin

In this article, maleic anhydride was used to attain the modified β-cyclodextrin (MAH-β-CD), and the MAH-β-CD was copolymerized with acrylamide (AM), acrylic acid (AA), and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) via free radical copolymerization. The polymerization conditions were optimized through single-variable method. Subsequently, the copolymer structure was characterized through Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (¹HNMR) spectroscopy, and scanning electron microscopy (SEM). The three-dimensional network structure formed in aqueous solutions was observed via experimental results of SEM. Subsequently, several aspects of the properties of the copolymer, such as temperature tolerance, shear tolerance, salt resistance, and oil displacement ability, were investigated by comparing with hydrolyzed polyacrylamide (HPAM). Results indicate that the copolymer showed better performances than HPAM; thus, it could be concluded that the introduction of β-cyclodextrin in the polymer chain was helpful in enhancing the oil displacement efficiency in high-temperature and high-salinity oil field.     

Synthesis, structure and photoluminescent property of a novel potassic compound

A novel 3D coordination compound of K(H2TDA)(H20)(1)(H_3TDA=1H-1,2,3-triazole-4,5-dicarboxylic acid) has been prepared and characterized by IR spectroscopy,elemental analysis,ICP and single-crystal X-ray diffraction.Compound 1 displays strong fluorescent emission at room temperature.     

Synthesis of peptide–cellulose conjugate mediated by a soluble cellulose derivative having β-Ala esters (II): conjugates with O-phospho-l-serine-containing peptides

A synthetic route is described here for novel peptide-cellulose conjugates containing O-phospho-l-serine. First, Boc-Ser(PO₃Ph₂) and the related dipeptides, Boc-Ser(PO₃Ph₂)-Asp(OBzl) and Boc-Asp(OBzl)-Ser(PO₃Ph₂), were synthesized by adopting the phosphoryl-protection strategy. The condensation reaction between the α-carboxyl group of the protected Boc-Ser(PO₃Ph₂) and the β-amino groups of β-Ala-Cellulose using isobutyl chloroformate and N-methylmorpholine yielded the product conjugate, N ^β -[Boc-Ser(PO₃Ph₂)]-β-Ala-Cellulose. The degree of substitution of Boc-Ser(PO₃Ph₂) towards the β-amino groups of β-Ala-Cellulose was estimated as DS ^N  = 0.75 (maximum, 1.0). Similar reactions between β-Ala-Cellulose and two kinds of protected dipeptides, Boc-Asp(OBzl)-Ser(PO₃Ph₂) and Boc-Ser(PO₃Ph₂)-Asp(OBzl), gave the corresponding conjugates, and the DS ^N was estimated to be 0.95 and 0.69, respectively. The phenyl, benzyl, and Boc groups were removed in one-pot using the Pt₂O catalyst in 50 % trifluoroacetic acid/acetic acid. The ³¹P-NMR and UV–Visible spectra indicated the complete deprotection without any observable elimination of the phosphorylated peptides.