Nitrogen charge

Note that diaphragm-type accumulators can be checked more easily and are more reliable than the less expensive bladder type. Here, a rubberized nylon diaphragm separates the nitrogen charge from the oil. An indicator rod protrudes into a transparent plastic dome and gives accurate, visual indication of tlie true volumes of nitrogen and lube oil. 

An oven-dried 100 ml flask with a side arm dosed with a septum is fitted with a magnetic stirring bar and a reflux condenser connected to a mercury bubbler. The flask is cooled to room temperature under nitrogen, charged with 4.36 g (0.025 mol) of adipic acid monoethyl ester followed by 12.5 ml of anhydrous tetrahydrofuran, and cooled to —18° by immersion in an ice-salt bath. Then 10.5 ml of 2.39 m (or 25 ml of 1 m) solution of borane in tetrahydrofuran (0.025 mol) is slowly added dropwise over a period of 19 minutes. The resulting clear reaction mixture is stirred well and the ice-salt bath is allowed to warm slowly to room temperature over a 16-hour period. The mixture is hydrolyzed with 15 ml of water at 0°. The aqueous phase is treated with 6 g of potassium carbonate (to decrease the solubility of the alcohol-ester in water), the tetrahydrofuran layer is separated and the aqueous layer is extracted three times with a total of 150 ml of ether. The combined ether extracts are washed with 30 ml of a saturated solution of sodium chloride, dried over anhydrous magnesium sulfate, and evaporated in vacuo to give 3.5 g (88%) of a colorless liquid which on distillation yields 2.98 g (75%) of ethyl 6-hydroxyhexanoate, b.p. 79°/0.7 mm. 

An oven-dried (Note 1), 500-mL, septum-capped, round-bottomed flask Is flushed with nitrogen, charged with 70 mL of tetrahydrofuran (THF) (Note 2) and cooled to -78°C. After the apparatus has cooled, 157 nt of a 2.1 M solution of butylllthiun (0.330 mol) (Note 3) is added using a 50-mL... 

Correlations between the shifts of atoms in analogous positions highlight the persistent role of the inductive effects. So, for example, the nitrogen charges of... 

The XPES of a number of ethylenediamine and cyano complexes, including [Cr(en)3]Cl3 and K3Cr(CN)6, have been measured in order to obtain the difference between die Nls and Cis binding energies. For the en complexes the AE values are related to o donation, and for the cyano complexes are mainly controlled by the nitrogen charge, which depends on the n back-donation. 27... 

Chloro-2-butyl Tellurium Trichloride15 A 100 ml flask fitted with a magnetic stirrer is flushed with nitrogen, charged with 1.67 g (6.2 mmol) of freshly sublimed tellurium tetrachloride, 0.36 g (6.4 mmol) of (Z)-2-butcnc, and 20 ml of ethanol-free chloroform, and immersed in an ice bath. The mixture is stirred for 3 h, filtered, and the filtrate is evaporated yield 1.35 g (67%), mixture of threo (80%) and erythro (20%) isomers. The mixture is recrystallized to yield the pure threo compound m.p. 107°. The erythro compound was not obtained in an isomerically pure state. 

Under a stream of nitrogen charge a single-necked round-bottomed flask (100 mL) with a magnetic stirrer bar, polymeric Hiinig s basec (4.55 g), and dry dioxane (11 mL). Stir the mixture for 30 min, then add a solution of crude aminal 8 (1.1 g, 2.6 mmol) in dry dioxane (23 mL) followed by thionyl chloride (0.8 mL). Stir the mixture at room temperature under nitrogen for 3 h. Filter off the insoluable polymeric base and evaporate the filtrate in vacuo to obtain the crude halide. 

A 100-ml flask was flushed with nitrogen, charged with platinum-divinyItetramethyl-disiloxane (200 mg) and 25 ml of toluene, and then stirred at ambient temperature. This mixture was treated with the Step 1 product (10.0 g) followed by the drop wise addition of trichlorosilane (20 g) at ambient temperature. The reaction mixture was stirred at 50° C for 48 hours and distilled, and the product was isolated in >95% yield. 

Based on the synthesis of ammonia at 300 atmospheres and 500° C., the yield is frequently above 98% while the conversion will be limited by the equilibrium figure of around 20%. This means that 80% of the hydrogen and nitrogen charged are not converted and must be recirculated after the removal of the ammonia. Somewhat higher figures prevail for the methanol synthesis. It is from the yields that the unit consumption factors are calculated. 

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