Schlenk line technique

The successful polymerization of a, >-dienes via ADMET continually produces a small molecule, typically ethylene, and the removal of this small molecule drives the reaction. When Schrock s [W] and [Mo] alkylidenes (14) are used, care has to be taken in maintaining an inert atmosphere devoid of both moisture and air in order to avoid decomposition of the catalyst. For this reason, Schlenk line techniques such as those used to handle Ziegler-Natta or metallocene catalysts and high purity monomers are important. 

All operations are carried out in a protective atmosphere of high-purity dinitrogen using standard Schlenk line techniques to prevent oxidation of the molybdenum(III) compounds and to avoid hydrolysis of the compounds by reaction with water vapor. Tetrahydrofuran (THF) (HPLC grade) is dried with 3-A molecular sieves 48 h prior to use. 

All operations are carried out under an inert atmosphere using standard Schlenk line techniques.1 Either deionized or distilled water which has been... 

All reactions and operations must be carried out under dinitrogen or under vacuum, using standard Schlenk line techniques. Diethyl ether, THF, and hexane are freshly distilled from sodium benzophenone ketyl under nitrogen. Toluene is freshly distilled from sodium under nitrogen. The compounds [Mo(t) -C5Hs)(CO)3]2, r-Bu2PH, and Me2AsH are prepared as described in the literature cited. 

Using standard Schlenk-line techniques, 200 mg of Rh2(02CCH3)4,-(MeOH)2 (0.395 mmol), 5 mL of a 1 M solution of (Et30) [BF4] in CH2CI2 (S.Ommol, Aldrich), and 10 mL of CH3CN (freshly distilled from calcium hydride) are refluxed in a 100-mL, three-necked, round-bottomed flask at... 

Most of the tricoordinate heterocycles are air-sensitive. Their handling requires at least inert atmosphere techniques, but in certain cases and particularly for bismuth compounds, Schlenk line techniques and glove boxes are required. Increasing CN decreases or eliminates air-sensitivity. 

Preparation of fl -dilithioferrocene-TMEDA [209] The whole procedure is carried out under an inert, dry atmosphere with freshly dried solvents stored under inert gas using standard Schlenk line techniques. n-Butyllithium (160 mL, 2.3 M) in -hexane), was added to 30 g (0.16 mol) of ferrocene (recrystallized from hexane), followed by 30 mL (0.20 mol) of N.N,N N -tetramethylethylenediamine (TMEDA, distilled from BaO under argon). The reaction was allowed to proceed overnight, ca. 16 h. The product was filtered off, washed with 3 x 100 mL of hexane, and dried imder vacuum. This gave 44.9 g (92% yield) of an orange pyrophoric powder, sensitive to moisture. The compound was recrystallized from THE at -40 °C. 

The syntheses of [Ln(OR)x] are air-sensitive because of their susceptibility to hydrolysis. Therefore, most work is performed under strict anhydrous conditions using glovebox and Schlenk line techniques. While the -1-2 and -f 4 states have... 

All manipulations were performed under a dry nitrogen atmosphere using a glove box and Schlenk line techniques, unless otherwise stated. The standard Schlenk line (A), Schlenk flask (B), transfer liquids technique (C), and filtration imder inert gas (D) are shown in Fig. 19.1. 

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