Sublimation in vacuum desiccator

Phenylenediamine [95-54-5] M 108.1, m 100-101 , pK O.67 (aq H2SO4), pKj 4.47 (4.85). Crystd from aqueous 1% sodium hydrosulfite (charcoal), washed with ice-water and dried in a vacuum desiccator, or sublimed in vacuo. It has been purified by recrystn from toluene and zone refined [Anson et al. J Am Chem Soc 108 6593 1986]. Purification by refluxing a CH2CI2 solution containing charcoal was also carried out followed by evaporation and recrystn [Koola and Kochi J Org Chem 52 4545 1987], protect from light. 

Tetracyanoethylene [670-54-2J M 128.1, m 199-200 (sealed tube). Crystd from chlorobenzene, dichloroethane, or dichloromethane [Hall et al. J Org Chem 52 5528 1987]. Stored at 0° in a desiccator over NaOH pellets. (It slowly evolves HCN on exposure to moist air.) It can also be sublimed at 120° under vacuum. Also purified by repeated sublimation at 120-130°/0.5mm. [Frey et al. J Am Chem Soc 107 748 1985 Traylor and Miksztal J Am Chem Soc 109 2778 1987.]... 

Iron ennecarbonyl (di-iron nonacarbonyl) [15321-51-4] M 363.7, m 100 (dec). Wash with EtOH and Et20 and dry in air. Sublimes at 35° at high vacuum. Dark yellow plates stable for several days when kept in small amounts. Large amounts, especially when placed in a desiccator spontaneously ignite in a period of one day. It decomposes in moist air. It is insoluble in hydrocarbon solvents but forms complexes with several organic compounds. [J Am Chem Soc 72 1107 7950 Chem Ber 60 1424 1927. ]... 

CHCI3, dried under vacuum and stored in a vacuum desiccator. Sublimes at 180°. 

Benzil dihydrazone should not be dried in a vacuum desiccator, for it sublimes easily. 

The product has a high vapor pressure and sublimes readily. Care should be taken in drying so that losses of product are not incurred. Drying briefly in a vacuum desiccator over Drierite is recommended. 

Lac sulfur 1s prepared by boiling a suspension of 33 g of calcium oxide and 50 g of sublimed sulfur (Fisher Scientific Company) in 200 mL of water for 30 min, then filtering the hot solution and acidifying the clear filtrate to pH 5 with hydrochloric acid. The precipitated sulfur is collected, washed with water, and dried in a vacuum desiccator. 

Decaborane [J7702-41-9] M 122.2, m 99.7-100 . Purified by vacuum sublimation at 80°/0.1mm, followed by crystn from methylcyclohexane, methylene chloride, or dry olefin-free-n-pentane, the solvent being subsequently removed by storing the crystals in a vacuum desiccator containing CaCl2. 

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