Carboxylic acid

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

Asymmetric Ring-Opening of Cyclopropyl Ketones with Thiol, Alcohol, and Carboxylic Acid Nucleophiles Catalyzed by a Chiral N,N'-Dioxide-Scandium(III) Complex

Abstract: A highly efficient asymmetric ring-opening reaction of cyclopropyl ketones with a broad range of thiols, alcohols and carboxylic acids has been first realized by using a chiral N,N'-dioxide-scandium(III) complex as catalyst. The corresponding sulfides, ethers, and esters were obtained in up to 99% yield and 95% ee. This is also the first example of one catalytic system working for the ring-opening reaction of donor-acceptor cyclopropanes with three different nucleophiles, let alone in an asymmetric version.

Functional groups modulate the sensitivity and electron transfer kinetics of neurochemicals at carbon nanotube modified microelectrodes

Abstract: The surface properties of carbon-based electrodes are critically important for the detection of biomolecules and can modulate electrostatic interactions, adsorption and electrocatalysis. Carbon nanotube (CNT) modified electrodes have previously been shown to have increased oxidative sensitivity and reduced overpotential for catecholamine neurotransmitters, but the effect of surface functionalities on these properties has not been characterized. In this study, we modified carbon-fiber microelectrodes (CFMEs) with three differently functionalized single-wall carbon nanotubes and measured their response to serotonin, dopamine, and ascorbic acid using fast-scan cyclic voltammetry. Both carboxylic acid functionalized and amide functionalized CNTs increased the oxidative current of CFMEs by approximately 2–6 fold for the cationic neurotransmitters serotonin and dopamine, but octadecylamine functionalized CNTs resulted in no significant signal change. Similarly, electron transfer was faster for both amide and carboxylic acid functionalized CNT modified electrodes but slower for octadecylamine CNT modified electrodes. Oxidation of ascorbic acid was only increased with carboxylic acid functionalized CNTs although all CNT-modified electrodes showed a trend towards increased reversibility for ascorbic acid. Carboxylic acid-CNT modified disk electrodes were then tested for detection of serotonin in the ventral nerve cord of a Drosophila melanogaster larva, and the increase in sensitivity was maintained in biological tissue. The functional groups of CNTs therefore modulate the electrochemical properties, and the increase in sensitivity from CNT modification facilitates measurements in biological samples.

Safe acidic hard surface cleaner

Abstract: An acidic aqueous cleaner, preferably in microemulsion form, which is of a pH in the range of one to four and is useful for cleaning hard surfaced items, such as bathtubs, sinks, tiles and porcelains, and even some such items which are not acid resistant, such as those of a European enamel known as zirconium white enamel, comprises synthetic organic detergent, such as a mixture of anionic and nonionic detergents, e.g., sodium paraffin sulfonate, higher fatty alcohol ethoxylate sulfate and higher fatty alcohol or phenol ethoxylate, carboxylic acid, e.g., mixture of succinic, glutaric and adipic acids, and phosphonic acid, e.g., aminotris(methylenephosphonic acid)in an aqueous medium. Preferably a phophoric acid is present to further improve protection of such European enamel surfaces. The acidic cleaner is useful to remove soap scum, lime scale and grease from surfaces and mentioned items without adversely affecting such surfaces, and removals of the scum, scale and grease is easy, being effected by applying the microemulsion to the surface to be cleaned, followed by wiping it off. Although the cleaned surfaces may be rinsed that is not necessary and the surface will be left clean and shiny after wiping, even without rinsing, or with minimal rinsing. In the described emulsions the carboxylic acid components effectively remove soap scum and lime scale, the detergents remove greasy soils and promote effective contact between the acid and the surfaces to be treated, and the combination of phosphoric and phosponic acids prevents acidic attack of the dicarboxylic acids on the surface being cleaned, with the phosphoric acid increasing protective action of the phosphonic acid component.

Intermediate for and fluorescent cyanine dyes containing carboxylic acid groups

Abstract: (2,3,3-Trimethyl-3-H-indol-5-yl)-acetic acid has been synthesized. Additionally, derivatives of (2,3,3-Trimethyl-3-H-indol-5-yl)-acetic acid have been prepared as intermediates for preparation of fluorescent cyanine biolabels. A derived dye, 5.5'-Dicarboxymethyl-3,3,3',3'-tetramethyl-1,1'-diethylindocarboc yanine, is a biolabeling substance with a brilliant red fluorescence.