Impurities mortars

The technique of trituration is frequently useful. The organic product is stripped of solvent and the oily residue is placed in a mortar and covered with a layer of a solvent in which it is only slightly soluble. The mass is ground with a pestle mixing in the solvent as thoroughly as possible. In favorable cases, the solvent removes traces of impurities that may be inhibiting crystallization, and grinding action induces crystallization. 

In a septum vial NH4Re04 (268 mg, 1.0 mmol) and 4-ter/-butylphthalom trile (7 921 mg, 5.0 mmol) were melted at 290 C and held at this temperature for 45 min. After cooling, the dark-blue mixture was crushed in a mortar. The product was first chromatographed on alumina (neutral, 10% H20) with toluene as eluent to remove large amounts of impurities, then with EtzO to remove excess phthalonitrile 7, and again twice with toluene. A blue-green powder was obtained yield 55 mg (6%). 

The moist sulfide readily oxidises in air exothermally, and may reach incandescence. Grinding in a mortar hastens this [1]. The impure sulfide formed when steel processing equipment is used with materials containing hydrogen sulfide or volatile sulfur compounds is pyrophoric, and has caused many fires and explosions when such equipment is opened without effective purging. Various methods of purging are discussed [2], Formation of pyrophoric FeS in bitumen tanks is considered as a cause of spontaneous ignition and explosion in the head space [3], A detailed study of formation of possibly pyrophoric sulphides from rust in crude oil tankers has been made [4],... 

Various procedures for the purification of specific amine-boranes have been reported.12 Ethylenediamine-bisborane can be purified conveniently by aqueous extraction to remove water-soluble impurities. The crude product obtained from the tetrahydrofuran solution is ground to a fine powder in a mortar and added in small portions, with stirring, to about 75 ml. of water which has been cooled in an ice-water bath. Foaming may occur during this treatment. The white crystalline solid which does not dissolve is collected by filtration through a coarse-fritted-glass funnel and washed several times with small portions of cold water (about 5°C.). The final wash filtrate should be neutral toward pH paper. The product is dried by... 

If the cuprous chloride was not dried thoroughly it will turn green on standing. This is due to the formation of basic cupric chloride. The colored impurity may be removed by grinding the preparation in a mortar with enough 0.5 N H2SO4 to make a thin paste. When all the lumps have been removed pour the mixture into 400 cc. of distilled water and repeat the filtration and washings with alcohol and ether. 

Now cover the mercury with dried and powdered sea salt. Mix these two completely using a mortar and pestle. Depending on the impurities in the mercury, the salt may darken even to blackness. Wash this dirty salt out using rainwater and repeat the salt washing once or twice. The mercury will retain some of the subtle essence of the salt which is important for the rest of the processes. 

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