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1.
Reactivity of alkaline salts of isocyanuric acid has been studied. It has been established that the nucleophilic substitution is not selective because of the protonic exchanges between salts and substituted derivatives. The synthesis of mono or trisubstituted derivative is due to secondary reactions and to solvent effects. With this study, it has been possible to settle a method to prepare mono and trisubstituted derivatives of isocyanuric acid.  相似文献   

2.
The reaction between isocyanuric acid and ethylene carbonate results in the formation of polyetherols. The kinetic and mechanistic studies revealed that the initial step of the reaction is zero order related to ethylene carbonate. The rate‐limiting step is the decomposition of an intermediating dianion of ethylene dicarbonate into ethane‐1,2‐diolate dianion and carbon dioxide. Imide groups of isocyanuric acid inhibit the reaction. The mechanism of reaction was confirmed by spectroscopic methods. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 512–522, 2009  相似文献   

3.
The kinetics and mechanism of the reaction between isocyanuric acid and ethylene carbonate was studied. The multistep reaction in the presence of potassium carbonate as catalyst leads to polyetherols. The imide and hydroxyl groups of intermediates react with ethylene carbonate by slightly different mechanism and kinetics. The rate constants for these elementary processes were established, and based on these experimental data the mechanism of reaction was proposed. Using the isocyanuric acid and 1,3,5‐tris(2‐hydroxyethyl)isocyanurate, it has been found that the reaction of ethylene carbonate with intermediates occurs via a mixed mechanism. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 523–531, 2009  相似文献   

4.
Of the bromo derivatives of isocyanuric acid, unknown until 1967, dibromoisocyanuric acid (DBI) has proved to be a particularly powerful brominating agent, which can be easily handled in the laboratory.The chemistry ofDBI has been studied in depth by determination of the hydrolysis and dissociation constants, the redox potential in aqueous solution, and by investigation of its thermal behaviour, reaction with alkali ions (salt formation) and tertiary nitrogen compounds (formation of complexes). Its superiority as a brominating agent to other N-bromo compounds derives from the highly positive character of the bromine. The differences between the chloro-, bromo- and iodoisocyanuric acids are discussed, and related to the respective N-halogene and C–N bonding strengths.

Mit 2 Abbildungen  相似文献   

5.
It is shown that the catalytic and thermal rearrangements of cyanuric acid triallyl esters to isocyanuric acid esters proceed via inter- and intramolecular mechanisms. Cross-reaction products are formed when the reaction is carried out with a mixture of homologs, while the reaction in the presence of a hydroxy-containing compound gives its allyl ether and diallyl isocyanurate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 24, No. 3, pp. 376–379, March, 1988.  相似文献   

6.
由氯甲基化低交联聚苯乙烯和异氰尿酸在三乙胺作用下反应,制得了凝胶型交联聚苯乙烯-异氰尿酸树脂,测定了该树脂对苯酚和间苯二酚在不同温度下的吸附等温线,依据Clapeyron0Clausius方程从吸附等温线计算出了吸附热,从热力学的角度论证了树脂是基于氢键键合的疏水作用而吸附苯酚和间苯二酚的。  相似文献   

7.
Several anion‐π complexes of isocyanuric acid, thioderivatives and their halogen substituted derivatives with chloride anion have been studied. The geometric and energetic features, charges transfer from chloride anion to the aromatic rings and “atoms‐in‐molecules” analysis are performed and discussed for these complexes. The results show that the strength of the anion‐π interaction between cyanuric derivatives and chloride anion can be tuned by halogen‐substituting. The localized molecular orbital energy decomposition analyses shows that, in the total interaction, exchange and electrostatic energies are the dominant stabilizing forces, and the polarization energies also make a favorable contribution. Finally, solvent effect significantly weakens the anion‐π interaction between the isocyanuric derivatives and chloride anion, especially in polar solvents. © 2015 Wiley Periodicals, Inc.  相似文献   

8.
A second‐generation supramolecular dendrimer has been prepared by orthogonal multiple hydrogen bonding. In the first (inner) recognition domain, the interaction of one bis‐isocyanuric acid ( 25 ) with two branching units ( 21 ) that carry complementary Hamilton receptors has been exploited. In the second (outer) generation, the two ADDA (A=hydrogen‐bond acceptor, D=donor) receptors of each branching unit ( 21 ) have bound complementary DAAD units ( 4 ). The problem of limited solubility of the building blocks has been overcome by the introduction of branched ethylhexyl residues and by the use of flexible alkylene or oligo(ethylene glycol) linking chains. The orthogonal binding of the two hydrogen‐bonding pairs was elucidated by chemical induced shift NMR titrations, which proved that the two pairs, isocyanuric acid with the Hamilton receptor and ADDA with DAAD, bind preferentially. The formation of the supramolecular self‐assembled 1:2:4 dendrimer with a molecular weight of 5065 g mol?1 was investigated by diffusion NMR spectroscopy.  相似文献   

9.
Chlorocarbenium salts - of the Vilsmeier-Arnold type react with the silylated isocyanuric acid to give 1-oxa-3-azabutatrienium salts under mild conditions. From reactions of diarylchloromethenium salts - with and ketones or tertiary carboxamides high yields of 2-azaallenium salts were obtained. A few chloro substituted 2-azaallenium salts were prepared from and carbonyl compounds. The mechanisms of the new reactions are discussed.  相似文献   

10.
Five bis(isocyanuric) acid dimers have been prepared and characterised. The introduction of flexible alkyl chains was necessary to aid solubility. On mixing with N,N-bis(4-tert-butyphenyl)melamine in THF followed by slow evaporation, a viscous gel can form which is interpreted as evidence for the assembly of an infinite 2-D hydrogen bonded network.  相似文献   

11.
To establish the mechanism of reaction of formation of oligoetherols with perhydro‐1,3,5‐triazine ring, the kinetics of reaction of isocyanuric acid and 1,3,5‐tris(2‐hydroxyetyl) isocyanurate with ethylene carbonate resulting in formation of polyetherols in the presence of diazabicyclo[2.2.2]octane as a catalyst has been investigated. The kinetic and mechanistic studies revealed that the initial step of reaction is zero order related to ethylene carbonate and the reaction is inhibited by imide groups of isocyanuric acid. The mechanism of reaction was confirmed by spectroscopic and electrochemical methods. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 550–561, 2010  相似文献   

12.
Several structures of pi complexes of isocyanuric acid and of several thio derivatives with anions have been computed by using high level ab initio calculations. The nature of the complexes has been studied by means of the method of molecular interaction potential with polarization (MIPp) and Bader's theory of atoms-in-molecules. These molecules form favorable complexes with anions and can be used as binding units for building receptors for the molecular recognition of anions. In several cases, the anion-pi interaction has been demonstrated experimentally by means of X-ray crystallography.  相似文献   

13.
The effect of allyl derivatives of muconic, malonic, and isocyanuric acids, as well as some other unsaturated compounds on the properties of adhesives based on ethyl-and allyl-α-cyanoacrylates, is studied.  相似文献   

14.
I INTRODUCTIONIn our previous work, three series of macroporous hydrogen-bonding adsorbents have beenstudied, which were adsorbents with hydrogen donator, adsorbents with hydrogen acceptor, andadsorbents with both hydrogen donator and acceptor if-31. If a gel-type resin with hydrogendonator and/or acceptor contacts with a compound with hydrogen acceptor and/Or donatof, canthe gel-type resin sorb the compound based on of hydrogen bonding? Here we report the sorptionof phenol onto gel-type …  相似文献   

15.
Spherical crosslinked polystyrene-isocyanuric acid resin was synthesized by reaction of chloromethylated polystryene with isocyanuric acid.The sorption isotherms of phenol from aqueous solution and cyclohexane solution onto the resin were measured.It is of interest to notice that the resin sorbed phenol efficiently though its specific surface area was 0 and did not swell in water,and the sorption capactity from aqueous solution was close to that of phenol onto XAD-4 at the same equilibrium concentration.Sorption enthalpies calculated from the isotherms according to the Clausius-Clapeyron equation were -21-25kJ/mol and -39-41kJ/mol respectively.These values impled that the sorption processes were based on hydrogen bonding.In addition.the details of the hydrogen bonding between the active sites of the resin and phenol were suggested.  相似文献   

16.
Crystalline dihydrate of hemi-(diazonium-18-crown-6) isocyanurate of isocyanuric acid, 0.5[H2DA18K6]2+?(C3H2N3O3)??C3H3N3O3?2H2O, was prepared and investigated by X-ray crystallography. In the given structure the dication DA18K6 is center-symmetric and possesses crown conformation of approximate D3h symmetry. Molecule of isocyanuric acid and its anion are nearly planer. This molecule possesses approximate D3h symmetry and its anion possesses approximate C2v symmetry. With sufficient precision were determined geometrical parameters (bond lengths, bond angles etc.) of ions and molecules and was determined their packing in the given crystalline structure in which there is developed system of intermolecular (interion) hydrogen bonds.  相似文献   

17.
The stereoselective synthesis of a new amino acid phosphonium salt was described by quaternization of melting triphenylphosphine with the γ-iodo NHBoc-amino ester, derived from l-aspartic acid. The deprotection of the carboxylic acid function to afford the phosphonium salt with a free carboxylic acid group was achieved by a palladium-catalyzed desallylation reaction. This phosphonium salt was used in the Wittig reaction with aromatic or aliphatic aldehydes and trifluoroacetophenone, under solid-liquid phase-transfer conditions in chlorobenzene and in the presence of K(3)PO(4) as weak base, to afford the corresponding unsaturated amino acids without racemization. Thus, the reaction with substituted aldehydes allows to graft various functionalized groups on the lateral chain of the amino acid, such as trifluoromethyl, cyano, nitro, ferrocenyl, boronato, or azido. In addition, the reaction of the amino acid Wittig reagent with α,β-unsaturated aldehydes leads to amino acids bearing a diene on the lateral chain. Finally, this amino acid phosphonium salt appears to be a new powerful tool for the preparation of unsaturated and non-proteinogenic α-amino acids, directly usable for the synthesis of customized peptides.  相似文献   

18.
用离子交换树脂脱除氨基酸与盐混合液中的盐   总被引:10,自引:0,他引:10  
在用蛋白质酸性水解备氨基酸时,因中和残留的酸会使水解液中带入大量的盐。在进一步用离子交换色谱法分离混合氨基酸时,首先需脱掉其中的盐。本文用苯乙烯系强酸性阳离子交换树脂的盐型柱,根据氨基酸与苯乙烯系强酸性阳离子交换树脂之间既存在离子间的静电作用,又存在疏水作用,且二者之间存在协同作用,而盐在盐型苯乙烯系强酸性阳离子交换树脂柱上不保留的原理,用水作为洗脱剂,使盐和氨基酸(配制的盐和氨基酸混合液及含盐的毛发水解液)得到分离,本方法脱除氨基酸中的盐简单易行,用水作为洗脱剂即廉价由不造成污染,盐型树脂不用再生即可用于下次运行,研究了各种条件对分离性能的影响。  相似文献   

19.
The interaction of aluminum polyhydroxochloride sol and poly(4-vinylbenzene sulfonic acid) sodium salt is studied. It is found that, in dilute aqueous solutions at pH 4.6, aluminum polyhydroxochloride sol and poly(4-vinylbenzene sulfonic acid) sodium salt form insoluble polymer-colloid complexes of steady compositions. Potentiometric titration data show that the interaction between particles of aluminum polyhy-droxochloride sol and linear macromolecules of the polyelectrolyte occurs via salt bonds formed between unlikely charged groups on the surface of particles and units of the linear polyelectrolyte. The composition of the polymer-colloid complex is determined, and the degree of conversion for the reaction of aluminum poly-hydroxochloride sol and poly(4-vinylbenzene sulfonic acid) sodium salt is estimated. The influence of various polyelectrolytes on the stability of the polymer-colloid complex is studied.  相似文献   

20.
Thermogravimetric studies of the sodium salt of poly(acrylic acid), its modified sodium salt and its various metal complexes were made. The thermal stabilities of the various systems decreased in the order: poly(acrylic acid) > Ni(II) > Co(II) > Zn(II) > Fe(III) > Cu(II) > polymeric sodium salt. The higher thermal stabilities of the polymer-metal complexes result from the development of stable ring structures in the polymer matrix upon coordination with metal ions. The metal-ion complexation of carboxylate ligands of linear poly(acrylic acid), optimization of the complexation conditions and infra-red and ultraviolet-visible spectrometric characterizations are also illustrated.  相似文献   

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