- Structural and Thermodynamic Study of the Effect of Sterically Hindering Alkyl Groups on Complex Stability
-
The balance between steric and inductive effects on the thermodynamic stability of complexes in aqueous solution has been examined as the bulk of N-alkyl substituents is increased along the series methyl, ethyl, isopropyl, tert-butyl.The ligands 7,16-diisopropyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (L3), and RN2 (R = Me, L4; Pri, L5; or But, L6) have been prepared.The formation constants of these ligands, and of other ligands with bulky N-alkyl groups, have been determined with the metal ions CuII, ZnII, CdII, PbII and with CaII, SrII and BaII (L3 only).The N-isopropyl groups of of ligand L3 cause a sharp drop in thermodynamic complex stability for all metal ions, whereas in the series L2-L4 lead(II) is unusual in showing a strong increase in complex stability in response to the inductive effects of the larger alkyl groups.In an attempt to understand the lowering of complex stability by the N-isopropyl groups of L3 the crystal structure of the complex 3>I was determined: monoclinic, space group P21/c, a = 12.603(2), b = 14.875(3), c = 13.877(3) Angstroem, β = 112.81(1) deg, Z = 4, final R = 0.042.The structure indicates some stretching of the K-N bond by the presence of the N-isopropyl groups.The parallel between steric hindrance effects by bulky N-alkyl groups and hard and soft acid and base behaviour is discussed.
- Damu, Kirty V.,Maumela, Hulisani,Hancock, Robert D.,Boeyens, Jan C. A.,Dobson, Susan M.
-
-
Read Online
- Alkyl diethylene triamine derivatives and a process of the preparation thereof
-
The present invention relates to a novel triamine derivative among amine derivatives which are useful as a ligand of an organic metal complex for semiconductor deposition, and to a preparing method thereof. The preparing method of the present invention comprises the steps of: preparing di-hydroxy di-ethylene amine represented by chemical formula 2; substituting a hydroxyl group (OH) of the di-hydroxy di-ethylene amine with a halogen group; and preparing an alkyl di-ethylene triamine derivative represented by chemical formula 1.COPYRIGHT KIPO 2019
- -
-
Paragraph 0057-0060
(2019/03/20)
-
- METHOD FOR PRODUCING CIS- AND TRANS-ENRICHED MDACH
-
A process for preparing trans-enriched MDACH, including: distilling an MDACH starting mixture in the presence of an auxiliary, which is an organic compound having a molar mass of 62 to 500 g/mol, a boiling point at least 5° C. above the boiling point of cis,cis-2,6-diamino-1-methylcyclohexane, and 2 to 4 functional groups, each of which is independently an alcohol group or a primary, secondary or tertiary amino group. The MDACH starting mixture includes 0 to 100% by weight of 2,4-MDACH and 0 to 100% by weight of 2,6-MDACH, based on the total amount of MDACH present in the MDACH starting mixture. The MDACH starting mixture includes both trans and cis isomers. Trans-enriched MDACH includes 0 to 100% by weight of 2,4-MDACH and 0 to 100% by weight of 2,6-MDACH, where the proportion of trans isomers in the mixture is higher than the proportion of trans isomers in the MDACH starting mixture.
- -
-
-
- N-methyl diisopropanolamine preparation method
-
The invention relates to a N-methyl diisopropanolamine preparation method, which comprises: (1) adding diisopropanolamine and paraformaldehyde to a reactor, heating, vacuumizing, and carrying out a stirring reaction to obtain an intermediate product; (2) cooling the intermediate product to a room temperature, and adding a solvent to dilute so as to obtain a diluted product; and (3) adding the diluted product to the reaction kettle, adding a catalyst and a tertiary amine inhibitor, replacing the air in the reaction kettle with hydrogen, heating, carrying out a stirring reaction, and filtering to obtain the N-methyl diisopropanolamine product. According to the present invention, diisopropanolamine and paraformaldehyde are adopted as raw materials, and diisopropanolamine is adopted as the paraformaldehyde depolymerization agent to reduce the side reaction at the intermediate product synthesis stage so as to produce the high purity intermediate product; and the tertiary amines inhibitor is added at the hydrogenation reduction reaction stage, such that the possible amine removing reaction during the reaction process is avoided, and the yield of the synthesis reaction is improved.
- -
-
Paragraph 0021
(2017/01/12)
-
- Preparation method of N-alkyl diisopropanolamine
-
The invention discloses a preparation process of N-alkyl diisopropanolamine. The preparation process comprises the steps of respectively heating epoxypropane and N-alkylamine by virtue of a heat exchanger, mixing by virtue of a static mixer, introducing the mixture into a pipeline reactor for reaction, distilling out un-reacted N-alkylamine in a vacuum state, and rectifying out a small amount of N-alkyl monoisopropanolamine by virtue of a vacuum rectifying tower, so as to obtain N-alkyl diisopropanolamine. By synthesizing N-alkyl diisopropanolamine with the pipeline reactor, the preparation method has the advantages that the product quality is stable, by-products are few, the production efficiency is high, safety is high,the labor intensity of workers is low, the equipment investment is low, industrial continuous production is beneficially realized, and the like.
- -
-
Paragraph 0030-0037
(2017/04/27)
-
- PROCESS OF MAKING BETA-HYDROXYAMINO COMPOUNDS
-
The present application relates to molecules comprising one or more beta-hydroxyamine moieties, for example, aminosilicones and compositions such as consumer products comprising such molecules, as well as processes for making and using such molecules and such compositions. The aforementioned process is safer, more efficient and thus more economical. Thus, the aforementioned moleculers may be more widely used.
- -
-
Page/Page column 10
(2013/02/27)
-
- DINITROGEN REDUCTION
-
Metal-cluster complexes for the reduction of dinitrogen and dinitrogen containing compounds to produce ammonia, hydrazine and organic amines are disclosed herein. The presently disclosed embodiments also provide synthetic methods for preparing the metal cluster complexes, and for reducing dinitrogen and dinitrogen compounds using the metal cluster complexes.
- -
-
Page/Page column 12-13
(2008/06/13)
-
- Preparation of (meth) acrylic esters
-
A process for preparing (meth)acrylic esters by esterifying (meth)acrylic acid with monohydric or polyhydric alcohols comprises adding to the reaction mixture still comprising (meth)acrylic acid corresponding to an acid number of at least 5 mg of KOH per 1 g of reaction mixture at least one amino compound having at least one primary, secondary or tertiary amino group.
- -
-
-