New Strategy for the Synthesis of Diethylenetriaminetetraacetic Acid Functionalized Polysiloxane Ligand Systems

A new rout was used for the synthesis of porous solid polysiloxane matrix of the general formula P-(CH₂)₃N(CH₂COOEt)-(CH₂)₂N(CH₂COOEt)-(CH₂)₂-N(CH₂COOEt)₂ (where P represents [Si-O]_n) by the reaction of diethylenetriaminetrimethoxysilane with ethyl chloroacetate followed by polymerization with tetraethylorthosilicate via the sol gel process. The functionalized diethylenetriaminetetraacetic acid polysiloxane system (P-DETATA) was then obtained by acid hydrolysis of the diethylenetriaminetetraethylacetate functionalized polysiloxane(P-DETATAc). FTIR, ¹³C, ²⁹Si CP-MAS NMR and XPS methods were used for characterization of their chemical structure. The new functionalized ligand system exhibits high capacity to coordinate with divalent metal ions (Co²⁺, Ni²⁺, and Cu²⁺) than its analogous ligand obtained by postmodification of triamine polysiloxane with ethyl chloroacetate.     

Synthesis and Applications of a New Polysiloxane-Immobilized Macrocyclic Ligand System

Abstract

Insoluble porous solid, macrocyclic 22-membered ring, 1-oxa-6,9,12,15,18-pentaaza-2,22-disilacyclododocosane polysiloxane ligand system has been prepared by the reaction of a macro-silane agent with tetraethylorthosilicate. The macro-silane agent was prepared by the reaction of imino-bis(N-2-aminoethylacetamide) ligand with 3-iodopropyltrimethoxysilane in 1:3 molar ratio. The new prepared polysiloxane system exhibits variable potentials for the extraction of metal ions (Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Ag⁺, Cd²⁺, Hg²⁺, and Pb²⁺) from aqueous solutions. The ligand system shows high capacity to extract silver, lead, and mercury. Chemisorption of the metal ions by the ligand system at the optimum conditions was found in the order Ag ⁺ > Pb²⁺ > Hg²⁺ > Cu²⁺ > Ni²⁺ > Fe³⁺ > Co²⁺ > Cd²⁺ > Zn²⁺.     

Preparation and reactivity of metal containing monomers

The preparation of HTSC ceramics based on Y^III and Bi^III was studied. The polymers were obtained by two methods: by the reaction of preliminarily synthesized polyacrylic acid (PAA) or polyacrylamide (PAAm) with Y^III, Ba^II, and Cu^II nitrates or by copolymerization of metal containing monomers (metal (Y^II, Ba^II, and Cu^II) acrylates or acrylamide complexes of metal (Bi^III, Ca^II, Sr^II, Pb^II, and Cu^II) nitrates). The copolymerization was carried out in solution, in the solid phase, or using spontaneous polymerization, which has been previously discovered by the authors. The properties of the HTSC ceramics obtained are improved when the products of copolymerization of metal containing monomers are used.For part 41, seeIzv. Akad. Nauk, Ser. Khim., 1995, 885 [Russ. Chem. Bull., 1995,44, 858 (Engl. Transl.)].Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1096–1101, June, 1995.The authors wish to thank V. N. Topnikov and M. K. Makova for measuring the characteristics of HTSC ceramics and V. A. Zhorin for conducting copolymerization of metal containing monomers under high pressures combined with shear strains.The work was carried out with financial support of the International Science Foundation (Grant NJB 000).     

Preparation of Fluorescent Polystyrene via ATRP with Dimethylamino Chalcones as Initiator

4‐(3‐(4‐(Dimethylamino)phenyl)acryloyl)phenyl‐2‐bromo‐2‐methylpropanoate (APPBr) was used for the heterogeneous atom transfer radical polymerization (ATRP) of styrene (St) with copper(I) bromide/N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine (PMDETA) catalytic system. The functional end group was characterized via UV‐Vis and ¹H NMR spectra. The polymerization showed a first‐order kinetic characteristic and each of the obtained polymers had well‐controlled molecular weight and relatively low polydispersity index (PDI). Furthermore, the obtained end‐functionalized polystyrene (PS) in solution showed strong green‐light emission which is further affected by mixing different metal cations. In particular, the fluorescent intensity of the polymer was decreased in the presence of Ag⁺, Cu²⁺ and Fe³⁺.     

Synthesis of transition‐metal‐ion‐selective poly(N‐isopropylacrylamide) hydrogels by the incorporation of an Aza crown ether

A functionalized cyclam was synthesized by the attachment of a polymerizable acryloyl group to one of the four nitrogens on the cyclam molecule. The polymerization of the functionalized cyclam was performed with N‐isopropylacrylamide and N,N′‐methylene bisacrylamide, and the gels obtained were studied in the presence of different transition‐metal‐ion solutions. There was a drastic difference in the phase‐transition temperature (T_c) of the poly(N‐isopropylacrylamide) (PNIPAAm)/cyclam gel in comparison with the pure PNIPAAm gel. For the described system, a T_c shift of 15 °C was obtained. The presence of functionalized cyclam increased the hydrophilicity and T_c of the aforementioned polymer gels in deionized water (at pH 6) because of the presence of protonated amino moieties. The PNIPAAm/cyclam gels showed a dependence of the swelling behavior on pH. T_c of the pure PNIPAAm gel was weakly influenced by the presence of any transition‐metal ions, such as Cu²⁺, Ni²⁺, Zn²⁺, and Mn²⁺. The addition of Cu²⁺ or Ni²⁺ to the PNIPAAm/cyclam gel reduced T_c of the polymer gel, and a shift of approximately 12 °C was observed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1594–1602, 2003     

pH-Responsive Nanocomposites From Methylcellulose and Attapulgite Nanorods: Synthesis,Swelling and Absorption Performance on Heavy Metal Ions

A pH-responsive methylcellulose-g-poly(sodium acrylate)/attapulgite (MC-g-PNaA/APT) nanocomposite superabsorbent was prepared by the free-radical solution polymerization of methylcellulose (MC), sodium acrylate (NaA) and nanoscale attapulgite (APT) in the presence of the crosslinker N,N′-methylene-bis-acrylamide (MBA). The structure and morphology of the nanocomposite were characterized by FTIR, FESEM, TEM, XRD and EDS techniques, and the effects of the amount of MBA, MC and APT nanorods on swelling behaviors were also evaluated. Results indicate that NaA has been grafted onto MC macromolecular chains and APT nanorods participated in polymerization by its active silanol groups, and APT led to a better dispersion in the MC-g-PNaA matrix. The incorporation of APT clearly enhanced the swelling capacity and rate of the superabsorbent. In addition, the nanocomposite exhibited excellent absorption capacity on heavy metal ions, and its absorption amounts on Ni²⁺, Cu²⁺ and Zn²⁺ ions reached 9.86, 7.66 and 21.86 times greater than active carbon (AC). The biopolymer-based nanocomposite superabsorbents can be used as a potential water-saving material and candidate of AC for heavy metal ion absorption.     

Synthesis and characterization of new fluorinated photoactive polyamides based on xanthene pendant: Evaluation of antibacterial and heavy metal ions removal behavior

A series of novel organosoluble polyamides (PAs) bearing different functional groups such as flexible ether, substituted imidazole, and xanthene rings and electron-withdrawing CF₃ groups were synthesized from diamines and various dicarboxylic acids. The structures of diamines and PAs were fully characterized by elemental analysis, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance spectroscopy. The PAs showed good solubility in aprotic and polar organic solvents, with high thermal stability exhibiting the glass transition temperatures (T_gs) and 10% weight loss temperatures (T₁₀%) in the range of 184–277°C and 410–480°C in N₂ atmosphere, respectively. These polymers showed fluorescence emission upon irradiation with UV light. Diamine compounds and two of synthesized polymers were also screened for antibacterial activity against gram-positive and gram-negative bacteria, and the obtained results for all four combinations showed good inhibition. Extraction capability for heavy metal ions such as Cr³⁺, Pb²⁺, Hg²⁺, Cd²⁺, and Co²⁺ from aqueous solutions was also tested at 25°C and pH 7–8.     

Gibbs functions for transfer of divalent metal cations from water to water + methanol mixtures using potentiometry, polarography and solubility measurements

Gibbs functions for transfer from water to methanol and to a full range of water + methanol mixtures were obtained for Cu²⁺, Cd²⁺, Pb²⁺, Hg²⁺, Zn²⁺, Mg²⁺, Ca²⁺, Sr²⁺ and Ba²⁺ using potentiometric or polarographic measurements in these solvents. In addition, data were obtained from the solubility products of the alkaline-earth iodates. From values obtained by the different methods and literature data, a table of selected values is given.     

Synthesis,Characterization and Applications of Immobilized Iminodiacetic Acid-Modified Silica

Porous immobilized iminodiacetic acid modified silica of the general formula S—(CH₂)₃—N(CH₂COOH)₂, (where S represents [Si—O] _n siloxane network) has been prepared by replacement of the iodide in 3-iodopropyl modified silica with diethyliminodiacetate. The immobilized-diethyliminodiacetate ligand system (S-DIDA) was then hydrolyzed by hydrochloric acid to produce the immobilized iminodiacetic acid ligand system (S-IDA). The iodo functionalized modified silica (S-I) was prepared by polycondensation of Si(OEt)₄ and (MeO)₃Si(CH₂)₃I. The XPS and CP/MAS ¹³C NMR spectra showed that not all iodine atoms are replaced and that the hydrolysis of ethyl acetate groups are incomplete upon treatment with HCl. The immobilized iminodiacetic acid ligand system exhibits high potential for the uptake of various di- and trivalent metal ions such as (Mn²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺). Complexation of the iminodiacetate ligand system for the metal ions at the optimum conditions was found in the order: Cu²⁺ > Fe³⁺ > Ni²⁺ > Co²⁺ > Mn²⁺ > Zn²⁺. Stability studies of the iminodiacetate ligand system showed that a degradation of the siloxane network and leaching of some species occurred upon treatment with strong acid and base aqueous solutions.     

Synthesis and X-Ray Crystal Structure of New Oxathiacrown Ethers Containing Sulfoxide Group and Their Metal-Binding Properties: Highly Selective Receptors for Ag+ and Cu2+

Three new oxathiacrown ethers 1, 2 and 3 containing a sulfoxide group were synthesized in a simple way. Conductometric titration studies in pure acetonitrile were employed to invistigate their binding affinities towards Ag ⁺, Cu ²⁺, Pb ²⁺, Cd ²⁺, Zn ²⁺, Co ²⁺, Ni ²⁺, Cr ³⁺and Hg ²⁺. They were found to be selective for Ag ⁺ and Cu ²⁺ over the other metals investigated. Ligand 1 has the highest selectivity towards Ag ⁺. The structure of compound 3 was confirmed by X-ray crystallography.Supplementary Data relevant to this article have been deposited at the Cambridge Crystallographic Data Centre under the deposition number 232076.     

Synthesis and crystal structure of alkaline-earth metal cryptates of a ligand derived from 2,6-diformyl-pyridine

New alkaline-earth metal cryptates [ML](ClO₄)₂?·?solvent (M?=?Ca²⁺, Sr²⁺, Ba²⁺; L?=?1,4, 12,15,18,26,31,39,42,43,44-undecaazapentacyclo-[13.13.13.1^6,10.1^20,24.1^33,37]-tetratetraconta-4, 6, 8, 10(44), 11,18,20,22,24(43),25,31,33,35,37(42),38-pentadecaene) were synthesized by [2?+?3] template condensation of tris(2-aminoethyl)amine with 2,6-diformylpyridine and characterized by physical methods. The crystal structure of the calcium cryptate was determined. The central atom is nine coordinate with three pyridyl and six imino nitrogen atoms. The coordination polyhedron can be described as slightly distorted tricapped trigonal prism.     

Linear and Star-Shaped Extended Di- and Tristyrylbenzenes: Synthesis,Characterization and Optical Response to Acid and Metal Ions

Two linear 1,4-distyrylbenzenes and five star-shaped 1,3,5-tristyrylbenzene derivatives ( L_2a and L_2b , Y₀–Y₃ and Y_NBu ) were synthesized and spectroscopically characterized. The photophysical properties, optical response to acid and metal ions were investigated. Upon backbone extension of linear distyrylbenzenes or the introduction of dibutylanilines, the electronic spectra are redshifted. Incorporation of electron-deficient pyridyl units does not significantly affect the optical properties. Variation of the number of pyridine rings and substitution pattern tune the fluorescence response to acids and metal ions. The novel arenes discriminate Al³⁺, Mn²⁺, Fe³⁺, Fe²⁺, Cd²⁺, Ag⁺ and Hg²⁺.     

Synthesis and structure of a Schiff base and its bivalent transition metal complexes

A Schiff base (HCSmz) was synthesized via (E)-cinnamaldehyde with S-methyl dithiocarbazate and six bivalent transition metal complexes [M(CSmz)₂] (M=Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, and Hg²⁺) were prepared. The complexes were characterized by elemental analyses, IR, ¹H NMR, and UV-Vis spectra, and the Ni(II) and Zn(II) complexes were also characterized by single crystal X-ray diffraction. After tautomerism of thiotone to thioenol and deprotonization of the thioenol, two ligands chelate the metal by two nitrogens of azomethine and two sulfurs of thioenol. Ni(CSmz)₂ crystallizes in the centrosymmetric space group P2₁ /n with a perfectly square planar trans-configuration with Ni located at the center of the square; crystal packing is stabilized by intra- and intermolecular C–H···S hydrogen bonds. Zn(CSmz)₂ is in the mirror-symmetric space group I4₁ /a in a distorted tetrahedral geometry with two equivalent Zn–N and Zn–S bonds; crystal packing is stabilized by intermolecular C–H···π hydrogen bonds.     

High Yield Synthesis and Preliminary Spectroscopic Study of Mono-N-alkylated Cyclen Derivatives of Salicylic Acid

Selective and high yield synthesis of N-substituted salicylic acid derivatives of cyclen has been achieved by using a direct synthetic procedure under mild reaction conditions. The protonation constants of these compounds were determined by potentiometric titration. The complexing properties of the cyclen derivatives with metal cations were investigated by UV–Vis spectroscopy and ¹H NMR. The stability constants of Mg²⁺, Ca²⁺ and Sr²⁺ complexes with ligands 5 and 6 were determined.     

Synthesis and properties of poly(dipropargyl sulfoxide)

The preparation and cyclopolymerization of dipropargyl sulfoxide were studied. The polymerization of dipropargyl sulfoxide was carried out by various transition metal catalysts. WCl₆–EtAlCl₂, MoCl₅, and PdCl₂ catalyst systems were very effective. The resulting poly(dipropargyl sulfoxide) structures were characterized by NMR (¹H and ¹³C), IR, and elemental analysis to have conjugated polyene units. Poly(dipropargyl sulfoxide) prepared by PdCl₂ was mostly soluble in organic solvents such as DMF and DMSO. Thermal and oxidative properties of poly(dipropargyl sulfoxide) were also studied. The electrical conductivity of iodine-doped poly(dipropargyl sulfoxide) was 5.2 × 10^?2 Ω^?1 cm^?1. Comparisons of poly(dipropargyl sulfoxide) properties with other similar polymers from dipropargyl sulfur derivatives such as dipropargyl sulfide and dipropargyl sulfone were also carried out. © 1993 John Wiley & Sons, Inc.     

Synthesis of lanthanide carbonates

The normal carbonates of La³⁺, Nd³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Dy³⁺ and Ho³⁺ have been synthesized by the reaction of an aqueous suspension of the lanthanide oxide, M₂O₃, with CO₂ under supercritical conditions. The effect of temperature, between 25 and 50 °C, and pressure, from 68 to 240 atm, on the extent of conversion of the oxide to the carbonate has been investigated. Yields of 95% or better of the normal carbonates were obtained at a pressure of 100 atm after the reaction was carried out for 1 h. The higher the concentration of CO₂ dissolved in the aqueous phase, the higher the yield. The oxides of Pr³⁺, Tb³⁺, Er³⁺ and Yb³⁺, as well as ZrO₂ and CeO₂, either did not react at all or gave very low yields of carbonates under the experimental conditions that were employed.     

Synthesis and structures of complexes ofN-(2-aminoethyl)diaziridines with transition metal salts

A series of complexes ofN-(2-aminoethyl)diaziridines with transition metal salts (Zn²⁺, Cd²⁺, Ni²⁺, Co²⁺, Mn²⁺, or Fe²⁺) were synthesized. Their structures were established by IR and NMR spectroscopy. The structure of bis[1,2-bis(2-aminoethyl)diaziridine]cadmium(II) diperehlorate was confirmed by X-ray diffraction analysis. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1910–1914, November, 2000.     

Studies on Synthesis of a Cycloheptapeptide and Effects of Different Metal Ions on the Cyclization

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Synthesis of Nanocrystalline Polycalix[4]amides Containing Mesogenic Triazole Units and Investigations of Their Thermo Physical Properties and Heavy Metal Sorption Behavior

Novel polyamides bearing calix[4]arene and triazole units, polytriazolecalixamides (PTCAs), were prepared by direct polycondensation of a new bistriazole substituted dicarboxylic acid derivative of calix[4]arene with commercial diamines. The polytriazolecalixamides were obtained in high yields and possessed inherent viscosities in the range of 0.42–0.59 dl/g. These polytriazolecalixamides were readily soluble in polar aprotic solvents such as NMP, DMSO, DMAc at room temperature and in THF by heating. Nanocrystalline structures were determined by XRD patterns and confirmed by DSC as well as TEM and AFM imaging techniques. The photophysical study was performed by UV-absorption spectroscopy and maximum wavelength for each polymer specified in details. Glass transition temperatures were between 134 and 154°C. Thermogravimetric analysis showed that these polyamides displayed high thermal stability ranged from 273 to 312°C at the point of 10% weight loss, and char yields were about 51.4–67.4% at 600°C in nitrogen. All of these nanocrystalline polycalixamides showed promising sorption properties towards transition metal ions such as Cu²⁺, Cr²⁺, Co²⁺, Cd²⁺ and especially Pb²⁺ in solid-liquid extraction which fulfill our needs in synthesizing novel high performance polyamides.     

Synthesis of polyacrylamide samples of known steric structure

The esterification of atactic, syndiotactic and isotactic samples of poly(acrylic acid) by phenol and p-nitrophenol, carried out at 95° in the presence of POCl₃, led only to atactic poly(phenyl and p-nitrophenyl acrylates) respectively, as shown by ¹H-NMR (250 MHz). These polymers and isotactic poly(phenyl acrylate), prepared by anionic polymerization of phenyl acrylate with n-butyllithium, when reacted with ammonia led to bridged polyacrylimides or to linear atactic or isotactic polyacrylamides according to the reaction conditions. Anionic homopolymerization of p-nitrophenyl acrylate did not occur.