Liquids, volatile, distillation storage

The contents of F2 are cooled with liquid nitrogen and F2 is attached to the apparatus (Fig. 3) while a slow nitrogen flow is passed through Si. Trap F4 contains a few drops of mercury and a small stirring bar, while F5 is an empty trap. High vacuum is applied to the system, and the valve S5 is closed. The Dewar flask is then removed from S2 and used to cool F4. Both [10B] Br3 and Br2 condense in F4. The temperature in F2 must not exceed 0° to prevent the vaporization of AlBr3. After all the volatile material has accumulated in F4, the valves S6 and S7 are closed and the contents in F4 warmed to room temperature. The liquid in F4 is now stirred for 30 min, and valve S7 is opened. Trap F5 is then cooled with dry ice/2-propanol, and valve S7 is opened. The impure [10B]Br3 is distilled at 0° from F4 into F5. This product may be further fractionated in a train of traps to remove traces of HBr. However, the [10B]Br3 obtained contains very little HBr, and another purification step is not necessary in most cases. The product is transferred into a vacuum storage flask. Yield 19.0 g (76%). ... 

Handling, Storage, and Precautions Fe(CO)5 is a volatile, flammable, and highly toxic liquid, which does not react with air at room temperature. It has a relatively high vapor pressure (21 mmHg at 20 °C). When Fe(CO)5 is exposed to light, Fe2(CO)9 impurity slowly accumulates. The monomeric pen-tacarbonyl complex can be purified by trap-to-trap distillation in a vacuum system, but for routine use this purification step is usually omitted. Use in a fume hood. 

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