A convenient synthesis of pyrroles catalyzed by acidic resin under solvent-free condition

A convenient and effective Paal-Knorr condensations of 2,5-hexanedione with most amines have been carried out at room temperature under solvent-free condition.Macroporous strongly acidic styrol resin(D001) as a novel,efficient,cost-effective,and reusable solid acid catalyst for the synthesis of pyrroles under the same conditions.The pyrroles were obtained in high yields in short reaction times.

Response surface methodology for optimizing adsorption performance of gel-type weak acid resin for Eu(Ⅲ)

The conditions relating to enhanced adsorption procedure of earth element europium（Eu） onto gel-type weak acid resin（110-H） in aqueous solution were optimized by means of the response surface methodology（RSM）, which proved that 110-H owned satisfactory adsorption capacity（346.85 mg/g） in optimum conditions, belonging to one of the high adsorption capacity materials. Then, the adsorption and desorption behaviors were investigated by batch studies. The adsorption performance showed high agreement with the Lagergren-first-order model and Langmuir isotherm with thermodynamic adsorption parameters of ΔH= 36.1 k J/mol and ΔS=200 J/（mol·K）. Desorption study revealed that 110-H could be effectively eluted by a low concentration of HCl solution（0.1 mol/L） to regenerate and reuse. Finally, the 110-H and Eu（III） loaded 110-H were characterized by IR spectroscopy and scanning electron microscope（SEM） to analyze the mechanism of adsorption, which proved to be chemisorbed.

Adsorption of Er(Ⅲ ) and Its Mechanism on Diglycolamidic Acid Resin

The adsorption behavior and mechanism of a novel chelate resin, diglycolamidic acid resin (DAAR) for Er(Ⅲ) were investigated. The optima adsorption condition of DAAR for Er(Ⅲ) is pH 6.20 in HAc NaAc medium. The statically saturated adsorption capacity is 189 mg·g -1 resin at 298 K. The Er (Ⅲ) adsorbed on DAAR can be eluted reaching 100% by 2 mol·L -1 HCl used as eluant. The resin can be regenerated and reused without apparent decreasing of adsorption capacity. The apparent adsorption rate constant is k 298 =1.94×10 -5 s -1 . The apparent activation energy is 24.7 kJ·mol -1 . The adsorption behavior of DAAR for Er(Ⅲ) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change Δ H of DAAR for Er(Ⅲ) is 24.1 kJ·mol -1 . The molar coordination ratio of the functional group of DAAR to Er (Ⅲ) is 3∶1. The adsorption mechanism of DAAR for Er (Ⅲ) was examined by using chemical method and IR spectrometry. The coordination compound is formed between oxygen atoms in the functional group of DAAR and Er(Ⅲ).

Studies on Adsorption Behavior and Mechanism of Copper(Ⅱ) onto Amino Methylene Phosphonic Acid Resin

The adsorption behavior and the mechanism of a novel chelate resin, amino methylene phosphonic acid resin(APAR) for Cu(Ⅱ) were investigated. Cu(Ⅱ) was quantitatively adsorbed by APAR in the medium of pH=4 09. The statically saturated adsorption capacity is 181 mg/(g resin). Cu(Ⅱ) adsorbed on APAR can be eluted by 1 0-3 0 mol/L HCl. The rate constant is k 298 =5 58×10 -5 s -1 . The adsorption of Cu(Ⅱ) on APAR follows the Freundlich isotherm. The Δ H of the adsorption is 3 91 kJ/mol. The apparent activation energy is E a=21 4 kJ/mol. The coordination molar ratio of APAR to Cu(Ⅱ) is 1/1. It is shown that the nitrogen and the oxygen atoms in the functional group of APAR coordinate to Cu(Ⅱ).

Adsorption behavior and mechanism of D113 resin for lanthanum

The sorption properties of macroporous weak acid resin （D113） for La^3＋ ion were studied by chemical analysis and IR spectra. Experimental results indicate that the D113 resin has a good adsorption ability for La^3＋ at pH = 6.0 in the HAc-NaAc medium. The statically saturated adsorption capacity is 273.3 mg/g. Separation coefficients of βLa^3＋/Ce^3＋, βLa^3＋/Gd^3＋, βLa^3＋/Er^3＋, and βLa^3＋/Y^3＋ are 2.29, 3.64, 4.27, and 0.627, respectively. The apparent activation energy of adsorption, Ea is 18.4 kJ/mol, the thermodynamics parameters AH, AS, and AG of sorption are 4.53 kJ/mol, 61.8 J/（mol·K）, -13.9 kJ/mol, respectively. The adsorption behavior of D113 for La^3＋ obeys the Freundlich isotherm. La^3＋adsorbed on resin can be eluted by 2.0 mol/L HCl quantitatively.

Sorption Behavior and Mechanism of Indium(Ⅲ) onto Amino Methylene Phosphonic Acid Resin

The sorption behavior of amino methylene phosphonic acid resin (APAR) for In (Ⅲ ) was investigated . Experimental results show that In ( Ⅲ ) adsorbed on APAR can be elated with 2mol · L -1 HCl. The apparent rate constant is k29 = 1.50 × 10-5s-1. The sorption behavior of APAR for In ( Ⅲ ) obeys the Freundlich isotherm. The themodynamic parameters of sorption, enthalpy change ()H, free energy change ()G and entropy change ()S of sorption (APAR) for In ( Ⅲ ) are 24.1 kJ·mol-1, -35. 1kJ· mol-1 and 200J· mol-1·K-1 respectively. The coordination molar ratio of the functional group of APAR to In( Ⅲ ) is 2:1. The sorption mechanism of APAR for In( Ⅲ ) was examined by IR spectrometry.

N-Arylation of azaheterocycles with aryl and heteroaryl halides catalyzed by iminodiacetic acid resin-chelated copper complex

Iminodiacetic acid resin-chelated copper(Ⅱ) complex is effective in cross-coupling reactions between azaheterocycles and aryl or heteroaryl halides,providing N-arylated products in good to excellent yields.The copper catalyst is air stable and can be readily recovered and reused with minimal loss of activity for three runs.

Sorption behavior of iminodiacetic acid resin for indium

In（Ⅲ） was quantitatively adsorbed by iminodiacetic acid resin （IDAAR） in the medium of pH = 4.52. The statically saturated sorption capacity of IDAAR is 235.5 mg·g^-1. 1.0 mol·L^-1 HCl can be used as an eluant. The elution efficiency is 97.9%. The resin can be regenerated and reused without apparent decrease of sorption capacity. The sorption rate constant is k298 = 1.94 × 10-5 s^-1. The apparent sorption activation energy of IDAAR for In（Ⅲ） is 20.1 kJ·mol^-1. The sorption behavior of IDAAR for In（HI） obeys the Freundlich isotherm. The enthalpy change is AH= 17.2 kJ·mol^-1.

STUDIES ON THE SORPTION OF MACROPOROUS PHOSPHONIC ACID RESIN FOR LANTHANUM

The influences of medium pH sorption temperature, sorption time, etc. on thesorption capacity of macroporous Phosphonic acid resin for La3+ were determined Thesorption rate constant was k298 = 7.64×10-5 s-1. The complex ratio of phosphonicgroups of the resin to La3+ was 3:1. The basic sorption parameters were determinedThe sorption mechanism of macroporous phosphonic acid resin for La3+ was examinedby chemical analysis and IR- spectrometry.

Adsorption of Macroporous Phosphonic Acid Resin for Nickel

Tje adsorption bchavior and mechanism of a novel chelate resin,macroporous phosphonic acid resin（PAR）for Ni（Ⅱ）were imestigated.The stotically saturated adsorption capacity is 64.3mg·g^-1 resin at 298K in HAc-NaAc medium.The Ni（Ⅱ）adsorbed on PAR can be eluted by 0.5mal·L^-1 HCl and the elution percentage reaches 96.6%.The resin can be regenerated and reused without abvious decrease in adsorption capacity.The apparent adsorption rate constant is k298=2.6×10^-5s^-1.The adsorption behavior of PAR for Ni（Ⅱ）obeys the Freundllich isotherm.The thermodynamie adsorption parameters.enthalpy change △H,free energy change △G and entropy change △S of PAR for Ni（Ⅱ）are 3.36kJ·mol^-1,-5.47kJ·mol^-1 and 29.6J·mol^-1·K^-1,respectively.The apparent activation energy is Ea=12.2kJ·mol^-1,The molar coordination ratio of the functional group of PAR to Ni（Ⅱ）is about 4：1.The adsorption mechanism of PAR for Ni（Ⅱ）was examined by a chemical method and IR spectrometry.

Adsorption of Pb^(2+) on macroporous weak acid adsorbent resin from aqueous solutions: Batch and column studies

The adsorption properties of a novel macroporous weak acid resin （D152） for Pb^2＋ were investigated with chemical methods. The optimal adsorption condition of D152 resin for Pb^2＋ is at pH 6.00 in HAc-NaAc medium. The statically saturated adsorption capacity is 527 mg/g at 298 K. Pb^2＋ adsorbed on D152 resin can be eluted with 0.05 mol/L HCI quantitatively. The adsorption rate constants determined under various temperatures are k288 n=2.22×10-5 s^-1, k298 K=2.51 × 10^-5 s^-1, and k308 K= 2.95 × 10^-5 s^-1, respectively. The apparent activation energy, Ea is 10.5 kJ/mol, and the adsorption parameters of thermodynamics are ΔH^Θ=13.3 kJ/mol, ΔS^Θ=119 J/（mol·K）, and ΔG^Θ298 K =-22.2 kJ/mol, respectively. The adsorption behavior of D152 resin for Pb^2＋ follows Langmuir model.

Adsorption Behaviors and Mechanism of Macroporous PhosphonicAcid Resin for Gadolinium

The adsorption behaviors and mechanism of a novel chelate resin, macroporous phosphonic acid resin(PAR)for Gd(Ⅲ)were investigated. The statically and dynamically saturated adsorption capacity is respectively 308 mg·g^(-1)resin and 296 mg·g^(-1)resin at 298 K in HAc-NaAc medium at pH 5.6. Gd(Ⅲ)adsorbed on PAR can be reductively eluted by 0.5～5.0 mol·L^(-1) HCl used as eluant and the elution percentage is up to 94.7% in 1.0 mol·L^(-1) HCl. The resin can be regenerated and reused without apparent decrease in adsorption capacity. The apparent adsorption rate constant is k_(298)=3.96×10^(-5) s^(-1). The adsorption behavior of PAR for Gd(Ⅲ) conforms to the Freundlich isotherm. The thermodynamic adsorption parameter, enthalpy change △H of PAR for Gd(Ⅲ)is 22.6kJ·mol^(-1). The apparent adsorption activation energy(Ea)of PAR for Gd(Ⅲ)is 5.0 kJ·mol^(-1). The molar coordination ratio of the functional group of PAR to Gd(Ⅲ)is about 3∶1. The adsorption mechanism of PAR for Gd(Ⅲ)was examined by using chemical method and IR spectrometry.

Studies on the Adsorption of Amino Methylene Phosphonic Acid Resin for Holmium(Ⅲ)

The adsorption behavior and mechanism of a novel chelate resin, amino methylene phosphonic acid resin (APAR) for Ho(Ⅲ) were investigated. The statically saturated adsorption capacity is 258 mg·g^(-1) resin at 298 K in HAc-NaAc medium. The Ho(Ⅲ) adsorbed on APAR can be repeatedly eluted by 3.0 mol·L^(-1) HCl and the elution percentage is as high as 95.8%. The resin can be regenerated and reused without apparent decrease in adsorption capacity. The apparent adsorption rate constant is k_(298)=1.14×10^(-5) s^(-1). The adsorption behavior of APAR for Ho(Ⅲ) obeys the Freundlich isotherm. The thermodynamic adsorption parameter, enthalpy change ΔH of APAR for Ho(Ⅲ) is 11.4 kJ·mol^(-1). The apparent activation energy is E_a=15.8 kJ·mol^(-1). The molar coordination ratio of the functional group of APAR to Ho(Ⅲ) is about 2∶1. The adsorption mechanism of APAR for Ho(Ⅲ) was examined by using chemical method and IR spectrometry.

SORPTION BEHAVIOR AND MECHANISM OF SAMARIUM(III) ON AMINO METHYLENE PHOSPHONIC ACID RESIN

Sm(III) was quantitatively adsorbed by amino methylene phosphonic acid resin (APAR) in the medium of pH=5.0. The statically saturated sorption capacity is 251mg/g·resin. Sm(III) adsorbed on APAR can be reductively eluted by 2.0mol/L HCl. The sorption rate constant is k298= 1.35×10-5s-1. The sorption behavior of APAR for Sm(III) obeys the Freundlich isotherm. The enthalpy change △H of sorption is 24.9kJ/mol. The apparent activation energy is Ea=11.7kJ/mol. The sorption mechanism shows that the nitrogen and oxygen atoms of the functional group of APAR coordinated with Sm(III) to form coordination bond.

ADSORPTION OF SAMARIUM(III) ON DIGLYCOLAMIDIC ACID RESIN

The sorption behavior and mechanism of a novel chelate resin, diglycolamidic acid resin (DAAR), for Sm(III) were investigated. The optimal sorption condition of DAAR for Sm(III) is pH=6.0 in HAc-NaAc medium. The statically saturated sorption capacity is 190mg/g resin at 298K. The Sm(III) adsorbed on DAAR can be eluted reaching 100% by 0.5~2.0mol/L HCl used as eluant. The resin can be regenerated and reused without apparent decrease of sorption capacity. The apparent sorption rate constant is k298= 1.96×10-5s-1. The apparent activation energy is 26kJ/mol. The sorption behavior of DAAR for Sm(III) obeys the Freundlich isotherm. The thermodynamic sorption parameters, enthalpy change 腍 of DAAR for Sm(III) is 16.9kJ/mol. The molar coordination ratio of the functional group of DAAR to Sm (III) is 3. The sorption mechanism of DAAR for Sm(III) was examined by using chemical method and IR spectrometry. The coordination bond was formed between oxygen atoms in the functional group of DAAR and Sm(III).

ADSORPTION OF MACROPOROUS PHOSPHONIC ACID RESIN FOR INDIUM

The adsorption kinetics and mechanism of a novel chelate resin, macroporous phosphonic acid resin (PAR) for In(III) were investigated. The statically saturated adsorption capacity is 216mg穏-1resin at 298K in HAc-NaAc medium. The apparent adsorption rate constant is k298=4.84?0-5 s-1. The adsorption behavior of PAR for In(III) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change △H, free energy change △G and entropy change △S of PAR for In(III) are 11.5kJ/mol, -12.6kJ/mol and 80.8J/mol稫, respectively. The apparent activation energy is Ea=3.5kJ/mol. The molar coordination ratio of the functional group of PAR to In(III) is about 3∶1.

Sorption Behaviour and Mechanism of Lanthanum (Ⅲ) on HD-2 Resin

La(Ⅲ) was quantitatively adsorbed by macroporous weak acid resin (HD-2) in the medium of pH=6.16. The statically saturated sorption capacity is 231 mg·g -1(resin). 3.0 mol·L -1 HCl can be used as an eluant. The elution percentage is 100%. The sorption rate constant is k_ 298=3.04×10 -5 s -1. The apparent sorption activation energy of HD-2 for La(Ⅲ) is 31.2 kJ·mol -1. The sorption behavior of HD-2 for La(Ⅲ) obeys the Freundlich isotherm. The adsorption parameters of thermodynamic are ΔH=9.56 kJ·mol -1, ΔS=35.7 J·mol -1·K -1, ΔG=-1.08 kJ·mol -1, respectively.

DCHA AS A NEW REAGENT FOR THE ESTERIFICATION OF OBSTINATED AMINO ACIDS BY THE MERRIFIELD'S RESIN

The obstinated amino acid,Boc-Asn(or Boc-Gln),was directly anchored onto the Merrifield's resin using DCHA as the base in present reaction.The yield(71.88%)of Boc-Asn-OCH_2-resin was much better than those(0-33.5%)using Cs_2CO_3,KOH,KF.DEA and TEA as the base.which are efficient reagents for other amino acids in the same reaction.

Adsorption of Iminodiacetic Acid Resin for Lutetium

The adsorption behavior and mechanism of a novel chelate resin, iminodiacetic acid resin (IDAAR) for Lu(Ⅲ) were investigated. The statically saturated adsorption capacity is 210.8 mg·g^(-1) at 298 K in HAc-NaAc medium. The Lu(Ⅲ) adsorbed on IDAAR can be eluted by 0.5 mol·L^(-1) HCl and the elution percentage reaches 96.5%. The resin can be regenerated and reused without obvious decrease in adsorption capacity. The apparent adsorption rate constant is k_(298)=2.0×10^(-5) s^(-1). The adsorption behavior of IDAAR for Lu(Ⅲ) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change ΔH, free energy change ΔG and entropy change ΔS of IDAAR for Lu(Ⅲ) are 13.1 kJ·mol^(-1), -1.37 kJ·mol^(-1) and 48.4 J·mol^(-1)·K^(-1), respectively. The apparent activation energy is E_a=31.3 kJ·mol^(-1). The molar coordination ratio of the functional group of IDAAR to Lu(Ⅲ) is about 3∶1. The adsorption mechanism of IDAAR for Lu(Ⅲ) was examined by chemical method and IR spectrometry.

Removal of Co(Ⅱ) from aqueous solutions by NKC-9 strong acid resin

A strong acidic ion exchange resin(NKC-9)was used as a new adsorbent material for the removal of Co(Ⅱ)from aqueous solutions.The adsorption isotherm follows the Langmuir model.The maximum adsorption capacity of the resin for Co(Ⅱ)is evaluated to be 361.0 mg/g by the Langmuir model.It is found that 0.5 mol/L HCl solution provides effectiveness of the desorption of Co(Ⅱ)from the resin.The adsorption rate constants determined at 288,298 and 308 K are 7.12×10-5,8.51×10-5and 9.85×10-5s-1, respectively.The apparent activation energy(Ea)is 12.0 kJ/mol and the adsorption parameters of thermodynamic are-H Θ=16.1 kJ/mol,-SΘ=163.4 J/(mol·K),-G Θ 298 K=-32.6 kJ/mol,respectively.The adsorption of Co(Ⅱ)on the resin is found to be endothermic in nature.Column experiments show that it is possible to remove Co(Ⅱ)ions from aqueous medium dynamically by NKC-9 resin.