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1.
Montmorillonite clay mineral shows remarkable ion exchange, intercalation and swelling properties. It can act as a good host for large organic molecules. Intercalated coordination compounds can be prepared in the interlayer spaces of montmorillonite structure. Cu(II)- and Ni(II)- exchanged montmorillonite sorb 8-hydroxyquinoline (oxine) to form corresponding coordination compounds of the exchanged metal ions. Such compounds have been characterised by means of elemental analysts, infrared spectroscopy, magnetic susceptibility data and X-ray diffraction. These compound show good thermal stability. 相似文献
2.
U. Hofmann 《Angewandte Chemie (International ed. in English)》1968,7(9):681-692
Kaolinite, illite, chlorite, montmorillonite, and vermiculite are among the most important of the clay minerals. Cations are embedded between the silicate layers and on the basal faces of the crystals. Whereas only the cations on the outer faces are exchangeable in the first three of the above minerals, those between the layers can also be replaced by others in montmorillonite and vermiculite. These characteristics and the ability of montmorillonite and vermiculite to undergo intracrystalline swelling and to form inclusion compounds are responsible for the industrial importance of kaolin and clay. The structure of halloysite is particularly interesting, since the silicate layers in this case are rolled up to form tabes. The possible role of the clay minerals as catalysts in the formation of petroleum and in the beginning of life is finally discussed. 相似文献
3.
This paper reports a simple procedure for coating fused-silica capillaries with poly(diallyldimethyl ammonium chloride) and montmorillonite. The coated capillaries were characterized by performing EOF measurements as a function of buffer pH, number of layers of coating, and number of runs (stability). The coated capillaries showed a highly stable mu(EOF) (run-to-run RSD less than 1.5%, n = 20), allowing continuous use for several days without conditioning. The coated capillaries were then used for the effective separation of nine environmentally important phenolic compounds showing a significant improvement in the resolution, when compared to bare fused-silica capillaries. The EOF of the coated capillaries was constant in alkaline solutions (pH > or = 7), allowing the optimization of the separation conditions of phenolic compounds without significantly affecting the mu(EOF). 相似文献
4.
M. A. Bañares-Muñoz M. C. Prieto-García M. A. Vivar-Cerrato M. A. Vicente-Rodríguez 《Journal of inclusion phenomena and macrocyclic chemistry》1994,17(1):25-35
The process of retention of ethyl 2-oxocyclopentanecarboxylate (EOCPC) by samples of natural bentonite containing Gador montmorillonite has been studied. Firstly, the adsorbent and the adsorbate were studied by different techniques. Intercalation compounds between them were prepared by two different methods: imbibition at room temperature and reflux heating at 60°C. The compounds obtained by both treatments were characterized structurally by X-ray diffraction (XRD), infrared spectroscopy (FT-IR), differential thermal analysis (DTA) and thermogravimetric analysis (TGA). 相似文献
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6.
János Vodnár Sándor Békássy Nicu Dulmi István Lrinczi Zoltán Hell 《Reaction Kinetics and Catalysis Letters》2004,83(1):165-171
The decomposition of p-isopropylcumene hydroperoxide on a catalyst of montmorillonite type containing Sn2+ ions, Sn2+-K10 showed first order kinetics in the range of 45-55°C. The activation energy, the enthalpy of activation, the entropy as
well as the Gibbs free energy of activation were calculated for the investigated temperature region. Acetone and p-isopropylphenol were produced by this chemical decomposition; both compounds are important intermediates in the chemical industry.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
7.
Wan-Po Yin 《Tetrahedron》2005,61(46):10861-10867
The nitration of phenolic compounds with 60% nitric acid (1.2 equiv) has been carried out in the presence of metal-modified montmorillonite KSF, prepared from different metals (V, Mo, W; Sc, La, Yb, Eu, In, Bi, Ti, Zr, Hf) and KSF or nitric acid treated HKSF, as catalysts. These catalysts showed good stabilities and high catalytic activities in nitration process. In addition, these catalysts can be recovered easily and reused for many times in nitration. This process is an eco-safer and environment-benign way for clean synthesis of nitrated phenolic compounds. 相似文献
8.
Irina V. Il'ina Konstantin P. Volcho Dina V. Korchagina Vladimir A. Barkhash Nariman F. Salakhutdinov 《Helvetica chimica acta》2007,90(2):353-368
The reactivity of allyl alcohols of the pinane series and of their epoxides in the presence of montmorillonite clay in intra‐ and intermolecular reactions was studied. Mutual transformations of (+)‐trans‐pinocarveol ((+)‐ 2 ) and (?)‐myrtenol ((?)‐ 3a ) were major reactions of these compounds on askanite–bentonite clay (Schemes 1 and 2). However, the two reactions gave different isomerization products, indicating that the reactivity of the starting alcohol (+)‐ 2 or (?)‐ 3a was different from that of the same compound (+)‐ 2 or (?)‐ 3 formed in the course of the reactions. (?)‐cis‐ and (+)‐trans‐Verbenol ((?)‐ 16 and (+)‐ 12 , resp.), as well as (?)‐cis‐verbenol epoxide ((?)‐ 20 ) reacted with both aliphatic and aromatic aldehydes on askanite–bentonite clay giving various heterocyclic compounds (Schemes 4, 5 and 7); the reaction path depended on the structure of both the terpenoid and the aldehyde. 相似文献
9.
蒙脱土修饰碳纤维电极的制备及其应用于活体测定脑神经递质 总被引:4,自引:0,他引:4
制备了蒙脱土修饰碳纤维电极,研究了其对神经递质多巴胺(DA)及5羟色胺(5HT)的富集作用,以及对负电性的代谢产物3,4二羟基苯乙酸(DOPAC)、5羟吲哚乙酸(5HIAA)及脑内大量存在的抗坏血酸(AA)排斥性能.该电极具有很高的灵敏度、分辨率和抗干扰性,对DA的检测下限达16×10-8mol/L,优于传统的Nafion修饰电极,对5HT的检测下限为1×10-7mol/L.在动物活体分析中,使用该电极成功地检测了大鼠双侧颈总动脉结扎再灌损伤时,脑纹状体中神经递质DA浓度的变化. 相似文献
10.
Polypyrrole–montmorillonite nanocomposite as sorbent for solid‐phase microextraction of phenolic compounds in water 下载免费PDF全文
Mir Mahdi Abolghasemi Sheyda Parastari Vahid Yousefi 《Journal of separation science》2014,37(23):3526-3532
A fiber‐coated polypyrrole–montmorillonite nanocomposite was prepared for solid‐phase microextraction. The fiber coating can be prepared easily; it is mechanically stable and exhibits relatively high thermal stability. The prepared fiber was evaluated for the extraction of some phenolic compounds from aqueous sample solutions by gas chromatography–mass spectrometry. The effects of the extraction and desorption parameters including extraction time, extraction temperature, stirring rate, ionic strength, pH and desorption temperature and time have been studied. At optimum conditions, the repeatability for one fiber (n = 5), expressed as % relative standard deviation was between 6.5 and 7.8% for the phenolic compounds. The detection limits for the studied phenolic compounds were between 0.05–1.3 ng/mL. The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost, thermal stability of the fibers, and high relative recovery in comparison to conventional methods of analysis. 相似文献
11.
Iraj Mohammadpoor-Baltork Mohammad mehdi Khodaei Abdol R. Hajipour Esmaeil Aslani 《Monatshefte für Chemie / Chemical Monthly》2003,134(4):539-543
Summary. An efficient and environmentally benign method for the conversion of oximes, semicarbazones, phenylhydrazones, and azines
to their corresponding carbonyl compounds using KMnO4/montmorillonite K-10 as a commercially available, non-toxic, stable, and inexpensive reagent is reported.
Corresponding author. E-mail: Imbaltork@sci.ui.ac.ir
Received August 23, 2002; accepted March 23, 2002 相似文献
12.
Primary and secondary benzylic alcohols were oxidized to the corresponding carbonyl compounds in good to high yields by environmentally friendly and green oxidant, H2O2 catalyzed by montmorillonite K-10 supported cobalt(Ⅱ) chloride. 相似文献
13.
Gholam Reza Najafi 《中国化学快报》2010,21(10):1162-1164
<正>Primary and secondary benzylic alcohols were oxidized to the corresponding carbonyl compounds in good to high yields by environmentally friendly and green oxidant,H_2O_2 catalyzed by Montmorillonite-K10 supported manganese(Ⅱ) chloride. 相似文献
14.
Ali Ezabadi Gholam Reza Najafi Mohammed M. Hashemi 《中国化学快报》2007,18(12):1451-1454
Oximes were oxidized to the corresponding carbonyl compounds in good to high yields by environmentally friendly and green oxidant, H202 catalyzed by montmorillonite K-10 supported cobalt(Ⅱ) chloride. 相似文献
15.
Majid M. Heravi Rahim Hekmatshoar Yahya S. Beheshtiha Mitra Ghassemzadeh 《Monatshefte für Chemie / Chemical Monthly》2001,132(5):651-654
Summary. Tetrahydropyranyl ethers were rapidly and selectively oxidized to the corresponding carbonyl compounds by clay supported
ammonium chlorochromate under solvent free conditions using microwaves.
Received July 25, 2000. Accepted September 7, 2000 相似文献
16.
Majid M. Heravi Yahya S. Beheshtiha Mitra Ghasemzadeh Rahim Hekmatshoar Nooshin Sarmad 《Monatshefte für Chemie / Chemical Monthly》2000,131(2):187-190
Summary. Ammonium chlorochromate adsorbed on montmorillonite K-10 rapidly regenerates carbonyl compounds from their corresponding
oximes under microwave irradiation and solvent-free conditions.
Received October 11, 1999. Accepted (revised) November 15, 1999 相似文献
17.
Fluoroalkylated 2-ylamino-imidazoles have been synthesized by reaction of 3-amino-5-phenyl-1,2,4-oxadiazole with fluorinated β-dicarbonyl compounds and subsequent base-induced Boulton-Katritzky Rearrangement (BKR) of the isolated β-enaminocarbonyl intermediate. Alternatively, one-pot reactions performed in the presence of Montmorillonite K10 favoured the condensation at the 3-amino moiety of the oxadiazole and, in some cases, allowed the direct synthesis of 2-benzoylamino-imidazoles. Hydrolysis of 2-benzoylamino-imidazoles easily yielded fluorinated 2-amino-imidazoles targets. 相似文献
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19.
The increasing use of organic compounds endangering the environment encourages search for more efficient sorbents. While crude clay minerals are effective for the adsorption of cations, modified organoclays may adsorb negative and hydrophobic molecules. In this short communication, we present a very fast adsorbing organoclay based on montmorillonite with crystal violet pre-adsorbed up to neutralization of the negative charges. Sorption of erythrosin-B and 2,4,5-trichlorophenol to such organoclay reaches equilibrium in less than a minute, whereas with activated carbon, it took tens of minutes. The pseudo second-order kinetic coefficient for the process was at least two orders of magnitude smaller for the organoclay. Because sorption kinetics is an important factor in water purification, such fast sorbent might have broad environmental applications. 相似文献
20.
《Journal of Saudi Chemical Society》2020,24(1):81-91
A range of heterogeneous, inexpensive and benign Schiff bases-montmorillonite composites were synthesized and screened for their antibacterial activity against common microbial pathogens. Sodium montmorillonite (Na-MMT) clay was modified with tris(2-ethylamine) in the presence of dilute HCl to yield a quaternary salt of tris(2-ethylamine) modified clay. The Schiff bases were then fabricated from the reaction of the modified montmorillonite using different aldehydes. The structures of the obtained compounds were confirmed by Fourier transformer Infrared (FT-IR), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA). All the obtained composite materials were screened for their antibacterial activities against the multi-drug resistant (MDR) strains. It was reasoned that the modified MMT-based composites has the ability to absorb the different micro-organisms onto the surface, and accordingly act as an effective antibacterial agent. All the composites showed significant antibacterial activity between 2.5 and 20 mg/mL against the MDR bacterial strains. The benzyl-based/modified MMT and the tertiary amino-based/modified MMT was found to be the most effective antibacterial agent. 相似文献