Shake and Bake

SnB uses the parameter-shift optimization of the minimal function by default whereas SHELXD uses the tangent formula. The complete direct-methods phasing process using the Shake-and-Bake algorithm is illustrated in flow-chart form in Fig. 9.2, and the main parameters are summarized in Table 9.4. 

Table 94 Recommended values of the major Shake-and-Bake parameters for substructure applications expressed in terms of N, the expected number of heavy atoms or anomalous scatterers...

Figure 9.4 Plots of the minimal-function value over 55 Shake-and-Bake cycles for (a) a solution and (b) a non-solution. Trial 5 illustrates the characteristic features of a solution - a small initial decrease in / mim value followed by a plateau, a sharp decrease over a few cycles, and a second plateau at a lower value. The first plateau may be shortened significantly if convergence to a solution occurs quickly.

Hauptman, H. A. (1997). Shake-and-bake an algorithm for automatic solution ab initio of crystal structures. Method Enzymol. 277,3-13. 

So here is the first surprise of the new developments of the eighties in superconductivity. Complex materials, compounds of as many as seven elements, were (and are) made by people who weren t supposed to be good at making them, physicists in particular. To some chemists this came as a shock. And to say that it was easy, that this solid state synthesis, the "shake-and-bake" methodology, is trivial, only allows the question to form in our minds, "If so, why did chemists not discover them earlier "... 

In practice, a combination of all three methods is used. Pressing the mixture into pellets is particularly useful, as it can also reduce the volatility of the reactants. A typical reaction scheme for the formation of LaFeOj is shown in Figure 4.4. The process of regrinding and heating is often referred to as the shake and bake method. It is a feature of most reactions carried out in the solid state. 

This chapter also contains descriptions of direct methods, including the Shake and Bake technique. 

The example of Li2MogSeg illustrates one synthetic method towards low dimensional mineral compounds, commonly referred to as the shake and bake method. It usually implies the mixing of the starting materials followed by a high temperature treatment. Then, in order to obtain a liquid crystal, one needs to bring these charged low-dimensional mineral anions into solution. Thus, how can one control, within a given ternary or quaternary system, the dimensionality of the synthesized polymeric compounds This problem has been addressed in the literature and an answer, based upon the 8-N electron rule, can be found... 

It is remarkable that the synthesis of the pure oxide NaNb30e is not straightforward and cannot be performed by the so-called shake and bake" reactions, as has been found for syntheses of oxoniobates containing the NbeO cluster. Below 1050 °C a mixture of NaNb03, NbO and Nb02 does not react. Above 1050 °C the... 

Infusion-related adverse effects of amphotericin B include chills and fevers (the shake and bake syndrome), muscle. spasms, nausea, headache, and hypotension. Antipyretics, antihistamines, and glucocorticoids have all been shown to be helpful. The administration of a 1 mg test dose of amphotericin B is sometimes useful in predicting the severity of infusion-related toxicity. The answer is (D). 

Of the catalysts listed in Table 6.1, the Mo(CO)6/4-chlorophenol system has been most widely utilized for the preparation of linear PPEs, most notably by Bunz [15]. This shake and bake method boasts inexpensive starting materials, a high ambient stability, and the use of undried, un-degassed solvents - which, overall, makes it an attractive catalyst system for polymerization. One particular advantage is that, in contrast to the much more sensitive Schrock catalysts, rigorous air- and moisture-free conditions are not required for a high conversion. Heteroatoms also... 

Livage J. Chimie douce from shake-and-bake processing to wet chemistry. New J Chem 2001 25 1-1. 

The synthetic route is important in inorganic chemistry, too, where the wealth of possible materials is hardly less than in organic chemistry. Inorganic synthesis has in the past often consisted of melting reactants together and cooling them under various conditions to obtain the hoped-for material (so-called shake-and-bake chemistry). This is being replaced by lower temperature, more controlled reaction schemes. Such controlled synthesis is important in the production of molecular sieves and certain ceramic materials that have an unexpected property They superconduct. 

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