Stainless steel cannulae

A solution of 5 (from 44.2 g of the dimer) in 750 mL of THF is added under nitrogen by forced siphon through a stainless steel cannula to a stirred, cooled ( —78 X) solution of 50.9 g (0.54 mol) of chloromethyl menthyl ether (6) in 150 mL of THF. After addition, the solution is allowed to warm to 25 X, stirred for an additional 2 h. then the solvent is removed under reduced pressure. 800 mL of pentane are added and the slurry is filtered through a cake of anhyd MgS04. Solvent removal and chromatography of the residue [alumina, hexane, then (C2H5)20/hexane 1 10] affords menthyloxymethyl complex 7 as an amber oil yield 78.5 g (91%). 

A stainless steel cannula with a 2-mm. inside diameter and both ends sharpened is inserted through the septum into the receiving flask above the surface of the liquid, and a stream of nitrogen is passed briefly through the stopcock and out the cannula to remove air. The other end of the cannula is then inserted through the septum on the reaction vessel, the end of the cannula in the receiver is pushed below the surface of the liquid, and the solvent is forced into the reaction vessel with nitrogen pressure. 

The sample is transferred through a stainless steel cannula connected to a Teflon holding loop and Master Laboratory Station (MLS). 

The checkers transferred cyclopentadiene by using a stainless steel cannula from a cooled (dry ice-methanol), 500-mL, round-bottomed flask to the reaction vessel. 

Ass a stainless steel cannula was not available, the checkers made a minori modification in the operation without any trouble. They transferred fthe supernatant pentane and the solution of the sodium enolate using a Luer-lock hypodermic syringe with a stainless steel needle, prefluslbed with nitrogen, and the apparatus was swept with nitrogen during this operation. 

The lilac colored reaction mixture is transferred into a second Schlenk flask (100 mL) using a double-ended stainless steel cannula. The second flask contains hexane previously cooled to — 78 °C (Dry Ice-acetone bath). A lilac colored solid precipitates. The solvent is siphoned off and the solid is washed three times with hexane (20mL) previously cooled to — 78 °C and transferred into the flask using the double ended cannula technique. The wash solvent is siphoned off and remaining solid is dried under vacuum (10-3torr, oil pump) at -40°C for 8h. Yields for MoCp(CO)3(FBF3) 282 319 mg (85-96%), for WCp(CO)3 (FBF3) 357-378 mg (85-90%). 

A stainless steel cannula inserted through this septum is connected by means of tygon tubing to a mercury bubbler. 

Titration calorimetry can be used to introduce a liquid to a solid or a liquid to a liquid. In this case, the sample is placed in a stainless steel ampoule and the liquid to be titrated is placed in an external reservoir. To avoid problems with temperature gradients the external reservoir should be maintained at the same temperature as the sample. The titrant enters the sample ampoule via a stainless steel cannula. The injections are computer controlled, and the amounts required are entered into the software before an experiment is initiated. 

Anhydrous diethyl ether and anhydrous tetrahydrofuran (THF) were obtained from Fisher Scientific Company. They were redistilled under nitrogen from dark blue or purple solutions of sodium benzophenone ketyl immediately prior to use. All transfers of these and other anhydrous materials were performed with syringes or stainless steel cannulas while carefully maintaining a nitrogen atmosphere. 

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