Carboxylic acid

About: Carboxylic acid is a research topic. Over the lifetime, 48544 publications have been published within this topic receiving 605696 citations.

Resist material and pattern forming method using the same

Abstract: PROBLEM TO BE SOLVED: To provide a resist material that has high resolution and also high sensitivity, achieves a favorable pattern profile after exposure to light and causes small line edge roughness,a chemically amplified positive resist material that has electrically conductive features and prevents charge-up during drawing, and a pattern forming method using the material.SOLUTION: The resist material is obtained by compounding a 1-20C mono- to tetra-valent carboxylate of metal selected from sodium, magnesium, chromium, manganese, iron, cobalt, nickel, copper, zinc, silver, cadmium, indium, tin, antimony, cesium, zirconium and hafnium, or a complex of the metal and β-diketones, into a resist material containing an acid generator and a polymeric compound prepared by (co)polymerization of a repeating unit of (meth)acrylate, styrene carboxylic acid or vinylnaphthalene carboxylic acid substituted with an acid-labile group and/or a repeating unit having a phenolic hydroxyl group substituted with an acid-labile group. The resist material shows significantly high contrast in an alkali dissolution rate before and after exposure, has high sensitivity and high resolution, gives a favorable pattern profile, and moreover suppresses an acid diffusion rate and causes small line edge roughness.

A structure-based catalytic mechanism for the xanthine oxidase family of molybdenum enzymes

Abstract: The crystal structure of the xanthine oxidase-related molybdenum-iron protein aldehyde oxido-reductase from the sulfate reducing anaerobic Gram-negative bacterium Desulfovibrio gigas (Mop) was analyzed in its desulfo-, sulfo-, oxidized, reduced, and alcohol-bound forms at 1.8-A resolution. In the sulfo-form the molybdenum molybdopterin cytosine dinucleotide cofactor has a dithiolene-bound fac-[Mo, = O, = S, ---(OH2)] substructure. Bound inhibitory isopropanol in the inner compartment of the substrate binding tunnel is a model for the Michaelis complex of the reaction with aldehydes (H-C = O,-R). The reaction is proposed to proceed by transfer of the molybdenum-bound water molecule as OH- after proton transfer to Glu-869 to the carbonyl carbon of the substrate in concert with hydride transfer to the sulfido group to generate [MoIV, = O, -SH, ---(O-C = O, -R)). Dissociation of the carboxylic acid product may be facilitated by transient binding of Glu-869 to the molybdenum. The metal-bound water is replenished from a chain of internal water molecules. A second alcohol binding site in the spacious outer compartment may cause the strong substrate inhibition observed. This compartment is the putative binding site of large inhibitors of xanthine oxidase.

Synthesis of Biobased Polyols by Thiol−Ene Coupling from Vegetable Oils

Abstract: A model study of the radical addition of 2-mercaptoethanol onto oleic acid was performed under mild conditions (generation of radicals under UV light at room temperature without any photoinitiator). To evaluate the efficiency and the robustness of thiol−ene reaction, experimental parameters were varied, such as the irradiation intensity (ranging from 0.5 to 15.0 W/cm2), the thiol/double bond ratio (ranging from 1.2/1 to 5.0/1), the solvent/double bond ratio (ranging from 0/1 to 500/1), and the number of double bonds per chain. It was especially shown that the higher the content of polyunsaturated fatty chains, the lower the rate of 2-mercaptoethanol grafting. Best yields were reached in 1 h reaction for a thiol/ene ratio of 3/1, without solvent, using maximum UV intensity. Side reactions, identified by NMR, FT-IR, LC-MS, and iodine titration, were upon esterification between the carboxylic acid function of oleic acid and the hydroxyl function of 2-mercaptoethanol, disulfide formation, double-bond isomeriz...

Cadmium mobilisation and plant availability – the impact of organic acids commonly exuded from roots

Abstract: The present work highlights metal-organic acid interactions with special reference to their plant availability Pot experiments were conducted to investigate the effect of various organic (carboxylic and amino) acids on the uptake and translocation of root-absorbed Cd by maize (Zea mays) plants grown in sand and soil culture Statistically significant increases in Cd accumulation from Cd-treated plants in the presence of increasing concentrations of organic acids, suggest the existence of Cd-organic acid interactions in the soil-plant system In order to support the above hypothesis of formation of organically bound Cd, separate experiments were performed to synthesize and estimate its various forms viz cationic, anionic and neutral The chemical nature of the organically bound forms was ascertained by electrophoretic experiments Amino acids have been found to be less effective in the mobilisation of cadmium compared to carboxylic acids The results are discussed on the basis of the potential of organic acids to form complexes with Cd

Asymmetric epoxidation with H2O2 by manipulating the electronic properties of non-heme iron catalysts.

Abstract: A non-heme iron complex that catalyzes highly enantioselective epoxidation of olefins with H2O2 is described. Improvement of enantiomeric excesses is attained by the use of catalytic amounts of carboxylic acid additives. Electronic effects imposed by the ligand on the iron center are shown to synergistically cooperate with catalytic amounts of carboxylic acids in promoting efficient O–O cleavage and creating highly chemo- and enantioselective epoxidizing species which provide a broad range of epoxides in synthetically valuable yields and short reaction times.