Nitro Disc

Nitro-Disc Nitrodisc Nitro-Dur Nitro-dur Nitro-Dur Nitro dyes Nitroesters Nitroethane Nitroethane [79-24-3]... 

A) Preparation of Naphthol Yellow S. Place 20 ml of concentrated sulfuric acid in an eight-inch test tube and heat to 100° in a water bath. Place a thermometer in the tube, and add 5 g of finely powdered commercial a-naphthol in about 1-2 minutes. Prepare a standard temperature bath for heating at about 120°, and transfer the tube into this bath. Heat for 3 hours. Remove the tube and allow to cool to room temperature, then pour with vigorous stirring into 30 ml of water. Place in a 250-ml beaker 5 ml of concentrated nitric acid and 1.5 ml of water. Cool in an ice bath, and add slowly the solution of the naphthol trisulfonic acid prepared above, keeping the temperature at 30-35°. After two minutes add slowly 4 ml of concentrated nitric acid, and stir. After five minutes remove the beaker from the ice bath, allow to stand for 15 minutes at room temperature, then warm to 50° for 10 minutes. Cool, and add 30 ml of saturated salt solution. Filter the nitro compound, and wash three times with saturated salt solution. Remove the cake to a 250-ml beaker and add 30 ml of water. Heat to 80°, and add solid sodium carbonate until the solution is neutral. Add 4 g of solid potassium chloride, and cool. Filter the precipitated dye, and dry on a filter disc or a porous plate. 

Mechanical a tation, which is usually dearable, is necessary when the reactants are immiscible. For example, in the ammonolysis of p-nitro-chlorobenzene u ng aqueous ammonia, the denser molten aromatic compound setti to the bottom if no agitation is provided. Agitation is frequently accomplished by means of high-speed propellers or vaned discs. Less intense a tation is provided by-gate, anchor, and paddle types of a tators. In laboratory shaker tubes, the agitation is accomplished by shaking the entire vessel. 

The effect of covering a gold disc with Pb ad-atom layers on the reduction of 3-nitro-l,2,4-triazole is shown in Fig. 6(a). Nitrotriazole undergoes a four-electron reduction both on Au and Au/Pb(upd) [56]. However, the reduction mechanism depends on the UPD ad-atom coverage. On bare Au and Au surfaces with almost complete ad-atom layer (E < 0.15 V), the four-electron reduction follows the ECE mechanism (Scheme 3). The reaction proceeds through a A,Ai -dihydroxyamine derivative (the hydrated form of the ni-troso intermediate) that is reduced further after an irreversible loss of water. Because of the slow rate of the dehydration... 

Another group of dielectrically interesting solids are the polysubstituted aromatics having at least four halogen, nitro or methyl group substituents. These molecules have the symmetry of circular discs and exhibit ready rotation about one axis. Two examples of such systems are presented in Table 4.1. 

Fig. 18.2. Enzyme patterns of some strawberry species Fragaria sp.) and Fragaria ananas) obtained by PAGE disc gel electrophoresis. Large pore concentrating gel pH 6.7, small pore separating gel, pH 8.9. 1 Peroxidase incubation with o-toluidine/H202 at pH 7. 2 Esterase incubation with a-naphthylacetate at pH 7, the released a-naphthol is diazotized and then coupled with p-chloroaniline. 3 Malate-dehydrogenase incubation with malate, nitro-blue-tetrazolium chloride and NAD at pH 7.5. (according to Drawert et al 1974)...

The disc-shaped plastic micoreactors, termed microcapillary films (MCFs), contain 19 parallel microchannels, each with a mean internal diameter of 142 10 pm. The material was prepared using a melt extrusion process from an ethylene-vinyl alcohol copolymer (EVOH) [28]. Immobilization of palladium(0) on the wall surface inside the MCFs was performed by simple chemical deposition techniques (Scheme 7.3). The palladium-coated capillaries were used for transfer hydrt enation of ketones, imines, nitro compounds, alkenes, and alkynes with triethylsilane under flow conditions [29]. Microcapillaries whose inside surfaces were coated with copper or gold were also utilized for the continuous-flow reactions [30]. 

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