Scheibler

The normal (or Scheibler) desiccator is provided with a porcelain plate having apertures to support crucibles, etc. this is supported on a constriction situated roughly halfway up the wall of the desiccator. For small desiccators, a silica triangle, with the wire ends suitably bent, may be used. The ground edge of the... 

Convenient types of vacuum desiccators are illustrated in Fig. 3.5. Large surfaces of the solid can be exposed the desiccator may be evacuated, and drying is thus much more rapid than in the ordinary Scheibler type. These desiccators are made of heavy glass, plastics, or even metal, and are designed to withstand reduced pressure nevertheless, no desiccator should be evacuated unless it is surrounded by an adequate guard in the form of a stout wire cage. 

Deposit character of, (eg) 509 Deposition completeness of, 507 potentials of metals, 508 Derivative spectrofluorimetry 733 Derivative spectrophotometry 668 Derivatisation in chromatography, gas, 236 liquid, 228 in fluorimetry, 735 Desiccants 99 Desiccators 98 cooling of crucible in, 100 desiccants for, 99 Scheibler type, 99 uses of, 100 vacuum, 100... 

Boncheva M., Scheibler L., Lincoln P., Vogel H., Akerman B., Design of oligonucleotide arrays at interfaces. Langmuir 1999 15 4317-4320. 

Scheibler A process for extracting sucrose from molasses residues, based on the precipitation of strontium saccharate. Operated in Germany in the late 19th century. 

Steffens A process for separating sugar from beet sugar molasses by adding calcium hydroxide to precipitate calcium saccharate. Treatment of the liquor with carbon dioxide precipitates calcium carbonate and regenerates the sucrose. Invented in Vienna in 1883 by C. Steffens. See also Boivan-Louiseau, Scheibler. 

Scheelite, 25 349-350 Scheelite sorting, 16 626 Scheibel column, 10 777-778 Scheibler filter, 11 364 Schiff base(s), 21 203, 204, 25 100-101 chelating agents, 5 712t reaction with amino acids, 2 567 reaction with aniline, 2 786 thermochromic materials, 6 622-623 Schiff base chemistry, 24 42 Schiff base (reductive amination) method, for covalent ligand immobilization, 6 396t... 

The method which is most certain, and the sole applicable to analytically pure preparations, consists in drying in a vacuum desiccator containing sulphuric acid. The old type of Scheibler is probably the most suitable. 

The reason why the acyloin synthesis is especially characteristic of aromatic aldehydes, depends on the circumstance that in the aromatic series the tertiary carbon atom in the ring does not allow of the aldol condensation, a reaction for which conditions are otherwise much more favourable. The simplest example of the acyloin condensation, moreover, was already encountered in the case of formaldehyde (p. 218) glycollic aldehyde is the simplest acyloin. Acyloin compounds are also produced, in the aliphatic series, by the action of sodium or potassium on esters, and hence are also formed as by-products in the acetoacetic ester synthesis (Bouveault, Scheibler). 

The Mechanism of the Ethyl Acetoacetate Synthesis—Before the tautomerism of ethyl acetoacetate is discussed we must consider the mechanism of its formation, which for decades has been the subject of lively discussion and was conclusively explained only in recent years (Scheibler). It has been found that even the C=0-group of the simple carboxylic esters, although in other respects inferior in activity to the true carbonyl group, can be enolised by alkali metals. Thus ethyl acetate is converted by potassium into the potassium salt of the tautomeric enol with evolution of hydrogen ... 

Boncheva M, Scheibler L, Lincoln P, Vogel H, Akerman B (1999) Langmuir 15 4317... 

All amino acids would be expected to behave in the same way as leucine, etc., but valine was found by Fischer and Scheibler in 1908 to behave differently —... 

As this monograph is going through the press a more recent publication by Fischer and Scheibler (Ber., 1908, 41, 2891) points to the probability of the Walden inversion occurring twice. 

C. ScHEiBLER. Zur Kenntniss der organischen Beslandtheile des Rubensaftes. Zeit. f. Chem., 1866, 278-280. 

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