2624-31-9Relevant articles and documents
Surface and interlayer base-characters in lepidocrocite titanate: The adsorption and intercalation of fatty acid
Maluangnont, Tosapol,Arsa, Pornanan,Limsakul, Kanokporn,Juntarachairot, Songsit,Sangsan, Saithong,Gotoh, Kazuma,Sooknoi, Tawan
, p. 175 - 181 (2016)
While layered double hydroxides (LDHs) with positively-charged sheets are well known as basic materials, layered metal oxides having negatively-charged sheets are not generally recognized so. In this article, the surface and interlayer base-characters of O2- sites in layered metal oxides have been demonstrated, taking lepidocrocite titanate K0.8Zn0.4Ti1.6O4 as an example. The low basicity (0.04 mmol CO2/g) and low desorption temperature (50-300 °C) shown by CO2- TPD suggests that O2- sites at the external surfaces is weakly basic, while those at the interlayer space are mostly inaccessible to CO2. The liquid-phase adsorption study, however, revealed the uptake as much as 37% by mass of the bulky palmitic acid (C16 acid). The accompanying expansion of the interlayer space by ~0.1 nm was detected by PXRD and TEM. In an opposite manner to the external surfaces, the interlayer O2- sites can deprotonate palmitic acid, forming the salt (i.e., potassium palmitate) occluded between the sheets. Two types of basic sites are proposed based on ultrafast 1H MAS NMR and FTIR results. The interlayer basic sites in lepidocrocite titanate leads to an application of this material as a selective and stable two-dimensional (2D) basic catalyst, as demonstrated by the ketonization of palmitic acid into palmitone (C31 ketone). Tuning of the catalytic activity by varying the type of metal (Zn, Mg, and Li) substituting at TiIV sites was also illustrated.
Iridium catalysts for acceptorless dehydrogenation of alcohols to carboxylic acids: Scope and mechanism
Cherepakhin, Valeriy,Williams, Travis J.
, p. 3754 - 3763 (2018/05/23)
We introduce iridium-based conditions for the conversion of primary alcohols to potassium carboxylates (or carboxylic acids) in the presence of potassium hydroxide and either [Ir(2-PyCH2(C4H5N2))(COD)]OTf (1) or [Ir(2-PyCH2PBu2t)(COD)]OTf (2). The method provides both aliphatic and benzylic carboxylates in high yield and with outstanding functional group tolerance. We illustrate the application of this method to a diverse variety of primary alcohols, including those involving heterocycles and even free amines. Complex 2 reacts with alcohols to form the crystallographically characterized catalytic intermediates [IrH(η1,η3-C8H12)(2-PyCH2PtBu2)] (2a) and [Ir2H3(CO)(2-PyCH2PtBu2){μ-(C5H3N)CH2PtBu2}] (2c). The unexpected similarities in reactivities of 1 and 2 in this reaction, along with synthetic studies on several of our iridium intermediates, enable us to form a general proposal of the mechanisms of catalyst activation that govern the disparate reactivities of 1 and 2, respectively, in glycerol and formic acid dehydrogenation. Moreover, careful analysis of the organic intermediates in the oxidation sequence enable new insights into the role of Tishchenko and Cannizzaro reactions in the overall oxidation.
Production of sucrose fatty acid ester
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Paragraph 0042, (2017/05/06)
PROBLEM TO BE SOLVED: monoester of selection of higher fatty acid ester. SOLUTION: the method of manufacturing the fatty acid ester, and sugar and basic catalyst and a process for preparing an aqueous solution containing, in the process and the resultant aqueous solution, and an alkali metal salt of a fatty acid, and other fatty acid ester is melted under a reduced pressure by mixing with the heated to generate a fatty acid ester and process, is provided, the process of generating a fatty acid ester, a mixture of water and a front-stage process, the process of step of performing, after having poststage and, in the process of poststage, by irradiation of microwaves, and less than the decomposition temperature of the mixture is heated so that the sugar. Selected drawing: no
