Supra

Procion dyes Procion H Procion H dyes Procion HE Procion H-E dyes Procion MX Procion MX dyes Procion P dyes Procion reactive dyes Procion Red H-E 7B Procion SP Procion supra dyes Procion T PROCOmi Proconvertin [9001-25-6] Proctitis... 

Sumifix Supra dyes SUMKAEXCEL Sumisdex Sumitomo C KS500 Summability equation Sumycin Sun... 

The impurities usually found in raw hydrogen are CO2, CO, N2, H2O, CH, and higher hydrocarbons. Removal of these impurities by shift catalysis, H2S and CO2 removal, and the pressure-swing adsorption (PSA) process have been described (vide supra). Traces of oxygen in electrolytic hydrogen are usually removed on a palladium or platinum catalyst at room temperature. 

Where larger quantities (upwards of Ig) are required, most of the impurities should be removed by preliminary treatments, such as solvent extraction, liquid-liquid partition, or conversion to a derivative (vide supra) which can be purified by crystallisation or fractional distillation before being reconverted to the starting material. The substance is then crystallised or distilled. If the final amounts must be in excess of 25g, preparation of a derivative is sometimes omitted because of the cost involved. In all of the above cases, purification is likely to be more laborious if the impurity is an isomer or a derivative with closely similar physical properties. 

Liquid amines can be further purified via their acetyl or benzoyl derivatives (vide supra). Solid amines can be recrystallised from water, alcohol, toluene or toluene-petroleum ether. Care should be taken in handling large quantities of amines because their vapours are harmful (possibly carcinogenic) and they are readily absorbed through the skin. 

Ketones are more stable to oxidation than aldehydes and can be purified from oxidisable impurities by refluxing with potassium permanganate until the colour persists, followed by shaking with sodium carbonate (to remove acidic impurities) and distilling. Traces of water can be removed with type 4A Linde molecular sieves. Ketones which are solids can be purified by crystallisation from alcohol, toluene, or petroleum ether, and are usually sufficiently volatile for sublimation in vacuum. Ketones can be further purified via their bisulfite, semicarbazone or oxime derivatives (vide supra). The bisulfite addition compounds are formed only by aldehydes and methyl ketones but they are readily hydrolysed in dilute acid or alkali. 

Because phenols are weak acids, they can be freed from neutral impurities by dissolution in aqueous N sodium hydroxide and extraction with a solvent such as diethyl ether, or by steam distillation to remove the non-acidic material. The phenol is recovered by acidification of the aqueous phase with 2N sulfuric acid, and either extracted with ether or steam distilled. In the second case the phenol is extracted from the steam distillate after saturating it with sodium chloride (salting out). A solvent is necessary when large quantities of liquid phenols are purified. The phenol is fractionated by distillation under reduced pressure, preferably in an atmosphere of nitrogen to minimise oxidation. Solid phenols can be crystallised from toluene, petroleum ether or a mixture of these solvents, and can be sublimed under vacuum. Purification can also be effected by fractional crystallisation or zone refining. For further purification of phenols via their acetyl or benzoyl derivatives (vide supra). 

A. Order [1,7] 1 +j supra/retention antara/inversion antara/retention antara/inversion... 

B. Order [i, j] i + j supra/supra supra/antara antara/antara ... 

Supra Retron. A structural subunit in a target molecule which consists not only of a complete retron for a particular transform but also of additional structural elements which signal the applicability and effectiveness of that transform. A supra retron contains ancillary keying groups in addition to those of the basic or minimal retron. 

Fig. 10 shows the radial particle densities, electrolyte solutions in nonpolar pores. Fig. 11 the corresponding data for electrolyte solutions in functionalized pores with immobile point charges on the cylinder surface. All ion density profiles in the nonpolar pores show a clear preference for the interior of the pore. The ions avoid the pore surface, a consequence of the tendency to form complete hydration shells. The ionic distribution is analogous to the one of electrolytes near planar nonpolar surfaces or near the liquid/gas interface (vide supra). 

As expected, the TgS of the hybrid sulfanuric-phosphazene polymers are much closer to the values reported for poly(phosphazenes) than those of sulfanuric polymers (vide supra). The values for the polymers 14.10a... 

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