23978-09-8Relevant articles and documents
Cryptand Exchange Kinetics
Cox, B. G.,Garcia-Rosas, J.,Schneider, H.
, p. 2434 - 2437 (1982)
The rate constants for some reactions between a metal cryptate MCry1n+ and a free cryptand Cry2 has been determined.For the case when Mn+ = Tl+, Ca2+, Cry1 = (2,2,2), (2B,2,2) and Cry2 = (2,2,1) in water or water-methanol mixtures, the observed rate constant correspond to that of the dissociation of MCry1n+.However, the exchange reactions Pb(2,1,1)2+ + (2,2,1) and Pb(2,1,1)2+ + (2,2,2) in MeOH present rates that are much larger than the dissociation rate of Pb(2,1,1)2+.A mechanism involving a bimolecular reaction between cryptate and free cryptand is proposed.
Solvent Dependence of the Kinetics of Formation and Dissociation of Cryptate Complexes
Cox, B. G.,Garcia-Rosas, J.,Schneider, H.
, p. 1054 - 1059 (1981)
The rates of dissociation of a variety of alkali metal cations and Ca2+ cryptates have been measured in several solvents.These have been combined with measured stability constants to give the corresponding formation rates.The dissociation rates are very sensitive to solvent variation, covering a range of more than 9 orders of magnitude.Except for (2,1,1) cryptates, formation rates are all within the range 106 - 109 M-1 s-1.Changes in stability constants, whether from a change in the cation, ligand, or solvent, are largely reflected in changes in dissociation rates.The properties of the transition state, particularly with the respect to solvent variation, most closely resemble those of the reactants, suggesting that the transition state lies close to the reactants.The dissociation rates increase sharply with increasing donor number of the solvent, whereas the formation rates decrease but are much less sensitive to solvent variation.On the basis of these correlations, formation rates in water are much lower than expected and dissociation rates much higher than expected.It is suggested that this is due to the H-bonded interactions between water and the electronegative atoms (O and N) of the ligands.
Kinetics of Dissociation of Potassium and Thallium Cryptates
Gresser, R.,Boyd, D. W.,Albrecht-Gary, A. M.,Schwing, J. P.
, p. 651 - 653 (1980)
The kinetics of dissociation of thallium cryptates (222Tl)+ and (221Tl)+ was studied in water and in methanol-water (90:10) over the range of temperatures 5-35 deg C.The kinetic behavoirs of (222Tl)+ and (222K)+ in water were compared.For the direct dissociation process the kinetic results have shown a similar behavior of (222K)+ and (222Tl)+ in water.A less solvating medium (methanol-water) than water leads to slower dissociation rates of the thallium cryptates studied.The acid-catalyzed dissociation path differentiates significantly, in terms of rate constants and activation parameters, the behavior of (222K)+ and (222Tl)+ in acidic aqueous medium.
The most convenient method for the preparation of aliphatic cryptands
Krakowiak,Krakowiak,Bradshaw
, p. 777 - 778 (1993)
An important new one-step method for the preparation of aliphatic cryptands from available oligoethyleneoxydiamines and ditosylates is reported.
Complex Formation of Alkaline-Earth Cations with Crown Ethers and Cryptands in Methanol Solutions
Buschmann, Hans-Jurgen
, p. 453 - 462 (1986)
The complexation of alkaline-earth cations by different crown ethers, azacrown ethers, and cryptands has been studied in methanol solutions by means of calorimetric and potentiometric titratios.The smallest monocyclic ligands examined form 2:1 complexes (ratio of ligand to cation) with cations which are too large to fit into the ligand cavity.With the smallest cryptand, only Sr2+ and Ba2+ ions are able to form exclusive complexes.In the case of the reaction of cryptand (211) with Ca2+, a separate estimation of stability constants for the formation of exclusive and inclusive complexes was possible for the first time.Higher values for stability constants are found for the reaction of alkaline-earth cations with cryptands compared to the reaction with alkali ions.This increase is only caused by favorable entropic contributions.
Preparation method of amino polyether (2.2.2)
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Paragraph 0026; 0033-0036; 0038; 0039; 0045-0049; 0050; 0056, (2018/11/27)
The invention belongs to the technical field of cryptand preparation, and concretely relates to a preparation method of amino polyether (2.2.2). The preparation method comprises the following steps: taking triglycol and paratoluensulfonyl chloride as raw materials, triethylene glycol di(p-toluenesulfonate) is obtained through a nucleophilic reaction, and then the material is subjected to a reaction with 2,2'-(ethylenedioxy)di(ethylamine), and through complexation and recrystallization, the amino polyether (2.2.2) is obtained; the reaction condition is mild and simple, a synthesis period can reduced to 27 h, the overall yield is no lower than 49%, and the method has the beneficial effects of short reaction period and high yield.
Process method for preparing cryptand 222
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Paragraph 0031; 0047; 0055-0060; 0061; 0069-0074, (2018/06/16)
The invention discloses a process method for preparing cryptand 222. The process method comprises the following steps: 1, taking tris[(2-ethylnenoxy)ethyl]amine as a raw material, and reacting to obtain an intermediate under catalytic actions of a Grubbs catalyst and alkali metal salts; and 2, adding a hydrogen source into the intermediate obtained in the step 1 under the catalytic action of a hydrogenation catalyst, and reacting, thereby obtaining the cryptand 222. The process method disclosed by the invention has the beneficial effects of short synthesis period and high yield.
Photocurable resin composition, dry film thereof, pattern forming method, and electrical/electronic part protective film
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, (2012/05/04)
A photocurable composition includes: (A) an epoxy group-containing polymer compound having repeating units represented by the following formula (1), where R1 to R4 are each a hydrocarbon group, m is an integer of 1 to 100, a, b, c and d are each 0 or a positive number, such that 0 (c+d)/(a+b+c+d) ≤ 1.0, and X and Y are each the formula (2) or (3), provided that at least one group of the formula (3) is present, (B) a photoacid generator represented by the formula (8) and (C) a solvent.
Resist composition and patterning process
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, (2010/02/17)
The present invention relates to: a resist composition such as a chemically amplified resist composition for providing an excellent pattern profile even at a substrate-side boundary face of resist, in addition to a higher resolution in photolithography for micro-fabrication, and particularly in photolithography adopting, as an exposure source, KrF laser, ArF laser, F2 laser, ultra-short ultraviolet light, electron beam, X-rays, or the like; and a patterning process utilizing the resist composition. The present invention provides a chemically amplified resist composition comprising one or more kinds of amine compounds or amine oxide compounds (except for those having a nitrogen atom of amine or amine oxide included in a ring structure of an aromatic ring) at least having a carboxyl group and having no hydrogen atoms covalently bonded to a nitrogen atom as a basic center.
POSITIVE RESIST COMPOSITION AND PATTERNING PROCESS
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, (2010/04/23)
A positive resist composition comprises (A) a resin component which becomes soluble in an alkaline developer under the action of an acid and (B) an acid generator. The resin (A) is a polymer comprising recurring units containing a non-leaving hydroxyl group represented by formula (1) wherein R1 is H, methyl or trifluoromethyl, X is a single bond or methylene, m is 1 or 2, and the hydroxyl group attaches to a secondary carbon atom. The composition is improved in resolution when processed by lithography.
