Vacuum line greaseless

Fig. 5.3. Wayda-Dye greaseless vacuum line. This apparatus makes extensive use of metal bellows tubing and O-ring seals. Thus the reaction vessels, filters, and other items can be tilted and manipu lated like Schlenk ware, and high vacuum conditions can be achieved for the removal of atmospheric gases and for baking out residual moisture. Trap to-trap distillation of volatile solvents such as NH) or SO is readily accomplished with this apparatus. This version is not designed for the measurement of volatiles or trap-to-trap separation. (Reproduced from A.L. Way da and J. L. Dye, J. Chent. Educ. 62, 356 (1985) by permission of the copyright owner the Division of Chemical Education of the American Chemical Society.)...

Moderate-Temperature Reaction. Gas-kinetics apparatus as shown in Fig. 2, including vacuum line with greaseless stopcocks, sample reservoir bulb, reaction vessel, heated mercury manometer regulated oil bath thermometer 500-mL beaker 1-qt Dewar stopwatch or other timer. 

FT-NMR spectrometer, with 10- or 15-mm-diameter probe capability if possible gas NMR tube with concentric Teflon valve (e.g., J. Young NMR-10) 1-L reaction flask with greaseless stopcock 0- to 1-bar pressure gauge vacuum line Ultra-Torr fittings microsyringes hot plate and oil bath with 0 to 200°C thermometer liquid N2 and ice baths benzoyl chloride and bromide, D2O (95 percent) fume hood. 

This review describes modular greaseless vacuum line systems which we have constructed in our laboratory for the synthesis and manipulation of air and moisture sensitive organometallic compounds. The discussion of these systems reviews important features of vacuum... 

These reactions require vacuum line techniques. Vacuum lines incorporating greaseless stopcocks are preferred over those greased with Kel-F or Apiezon N silicone grease reacts rapidly and must be avoided. 

The synthesis is carried out in a 500-ml., single-necked, round-bottomed flask which is connected to a standard vacuum line by means of a stopcock adapter. The stopcock adapter is important, since it allows for the easy attachment and removal of the reaction vessel from the vacuum line without exposing the contents of the reactor to air. The vacuum line must be equipped with a mercury manometer in order to measure the pressure of PH3 during the preparation of the Li[Al(PH2)4] solution. A conventional vacuum line with greased stopcocks is satisfactory. However, germyl-phosphine does attack conventional stopcock lubricants so a greaseless system is preferred if available. 

The reactions are carried out by standard vacuum-line techniques7 in an all-glass apparatus. Stopcocks may be greased, but the reaction itself is best carried out in a glass ampul with a greaseless stopcock. 

Fig. 2. Apparatus for the preparation of l(CiHs)2Ci-B 2FeH2. (A) Ball-and-socket connection to vacuum line (B) high-vacuum greaseless stopcock (C) side-arm tipper fitted with high-vacuum greaseless stopcock (D) coarse sintered-glass filter ( ) two-necked 100-mL round-bottom flask (F) single-neck J 00-mL round-bottom flask (G) magnetic stirring bar.

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