How Not to Discover a New Reagent. The Evolution and Chemistry of Woollins' Reagent

The pathways in research can be complex. This review provides a personal account of the winding scientific and funding road that led to Woollins' reagent. The synthesis and applications of Woollins' reagent are summarised.PostprintPeer reviewe

Post-processing treatment of conductive polymers to enhance electrical conductivity

A method for enhancing electrical conductivity of a film which includes at least one conductive polymer. The method includes providing the film comprising the at least one conductive polymer and at least one polymer acid, agitating the film in at least one reagent; and, placing the film on a heated surface. The at least one reagent includes a reagent acid that is stronger than the polymer acid. The conductivity of the treated film is significantly greater than the conductivity of the untreated film.Board of Regents, University of Texas Syste

A high-throughput screening method for determining the substrate scope of nitrilases

Nitrile compounds are intermediates in the synthesis of pharmaceuticals such as atorvastatin. We have developed a chromogenic reagent to screen for nitrilase activity as an alternative to Nessler's reagent. It produces a semi-quantifiable blue colour and hydrolysis of 38 nitrile substrates by 23 nitrilases as cell-free extracts has been shown

Synthesis of indoles via alkylidenation of acyl hydrazides

Indoles have been synthesised via alkylidenation of acyl phenylhydrazides using phosphoranes and the Petasis reagent, followed by in situ thermal rearrangement of the product enehydrazines. The Petasis reagent provides an essentially neutral equivalent of the [acid-catalysed] Fischer indole synthesis, but with acyl phenylhydrazides as starting substrates. Alkylidene triphenylphosphoranes convert aroyl phenylhydrazides to indoles, but acyl phenylhydrazides derived from aliphatic carboxylic acids undergo a Brunner reaction to form indolin-2-ones

SFGP 2007 - Investigation of a Novel Principle of Chemical Grafting for Modification of Cellulose Fibers

Natural cellulose fibres have been employed for packaging applications for a long time. Their use, however, has been hampered by their high hydrophilicity and their moisture sensitivity. It has, thus, been proposed to circumvent this problem through the hydrophobic modification of their surface thanks to the use of molecular grafting approaches. In this work, we describe the use of a novel solvent-free chemical pathway for molecular grafting that we have coined chromatogenic chemistry. It involves a reaction between a solid substrate and a reagent which is in a vapour-liquid equilibrium and diffuses within the solid substrate through a mechanism of adsorption/desorption akin to gas chromatography. Chromatogenic chemistry phenomenon has been studied and modelled through the extensive use of a new specific test, the Droplet Surface Migration Test. It involves the deposition upon a porous substrate of a small amount of reagent and in studying its subsequent migration and grafting. Whatman paper and various long chain acid chlorides were used for this modelling. The acid chloride carboxylic ends react with the external hydroxyl groups of cellulose fibres to give rise to the formation of long chain hydrophobic ester bonds. Upon immersion of the paper sheet in distilled water, a hydrophobic spot, extending well over the initial depot zone, could then be clearly visualized, allowing to follow conveniently the reagent migration and reaction. Grafting densities were performed by using the HPLC technique. The results obtained through the use of this test allowed a better understanding of chromatogenic chemistry phenomenon and an identification of the main parameters which affect the process: the nature of the reagent, the temperature, the reaction time, the nature of the substrate, etc. We have more particularly shown that the diffusion and grafting yields were maximal for a specific temperature which increases with the boiling point and therefore with the chain length of the reagents. We have proposed that this temperature should correspond to a compromise between the diffusion and reactivity properties of the reagent, its evaporation and its degradation by hydrolysis

A micromethod for the determination of arginine

Micromethods for the determination of arginine based on the use of the Sakaguchi reagent have been described (14). This reagent gives a strong color with glycocyamine, arginine, and other monosubstituted guanidine derivatives. In a previous communication (5) a method for the determination of glycocyamine was described based on the Sakaguchi reaction and the quantitative separation of glycocyamine from arginine by selective adsorption of the arginine on permutit. In the method outlined below the separated arginine is eluted from the permutit and determined independently

Method of neutralizing the corrosive surface of amine-cured epoxy resins

The corrosive alkaline surface layer of an epoxy resin product formed by the curing of the epoxy with an aliphatic amine is eliminated by first applying a non-solvent to remove most or all of the free unreacted amine and then applying a layer of a chemical reagent to neutralize the unused amine or amine functional groups by forming a substituted urea. The surface then may be rinsed with acetone and then with alcohol. The non-solvent may be an alcohol. The neutralizing chemical reagent is a mono-isocyanate or a mono-isothiocyanate. Preferred is an aromatic mono-isocyanate such as phenyl isocyanate, nitrophenyl isocyanate and naplthyl isocyanate

Micro mixer with fast diffusion

A concept for micromixing of liquid is introduced, and its feasibility is demonstrated. The mixer allows fast mixing of small amounts of two liquids and is applicable to microliquid handling systems. The mixer has a channel for the liquid, an inlet port for the reagent, a 2.2-mm×2-mm×330-μm mixing area, and 400 micronozzles (15 μm×15 μm) through with a reagent is injected into the sample liquid. The resulting microplumes greatly increase the contact surface between the two liquids and hasten the speed of the mixing by diffusion. The fabrication process is extremely simple. The mixing is complete within a few seconds; a homogeneous state of mixing is reached in 1.2 s when the total volume injected is 0.5 μl and the injection flow rate is 0.75 μl/

N-Triflylphosphorimidoyl Trichloride: A Versatile Reagent for the Synthesis of Strong Chiral Brønsted Acids

A series of strong Brønsted acids has been synthesized in high yields using N-triflylphosphorimidoyl trichloride as reagent. The syntheses proceed efficiently with electron-rich, electron-deficient, and sterically hindered substrates