Mixed Transformations

Since the number of domino processes which start with a Diels-Alder reaction is rather large, we have subdivided this section of the chapter according to the second step, which might be a second Diels-Alder reaction, a 1,3-dipolar cycloaddition, or a sigmatropic rearrangement. However, there are also several examples where the following reaction is not a pericyclic but rather is an aldol reaction these examples will be discussed under the term Mixed Transformations . 

All examples which do not belong to the above-described sections have been collected under the heading of Diels-Alder/mixed transformations. It is quite astounding which combinations have been put together. The following transformations have been used as a second step after the Diels-Alder reaction [2+2] cycload-... 

Mixed transformation rule Table l.c shows a mixed case where some input arcs are marked with variables x,y and other arcs by constants a, b]. Output arcs are marked with constants (c) and reversible functions f,g. This CPN inversion is a mix (generalization) of the basic transformation. Each variahle is used by one and only one function, hi the opposite case, see the Parametric transformation helow. 

In the interval 0 < T < 35 K, essentially all the Co(III) atoms of LaCoOj are LS. However, localized spins associated with surface cobalt [54, 55] give a weak ferromagnetism at 5 K see Fig. 13a. Strong Co e - 0 2p<, covalent mixing transforms the empty e orbitals of the bulk C0O3 array into a narrow a band of itinerant-electron states separated from a filled % band by an energy gap... 

GI materials, the second component is a powder produced from an ion-leachable aluminosilicate glass (9), whereas in ZP cements, the powder is essentially pulverized zinc oxide, containing, in some cases, small amounts of magnesium oxide (10). Both powders are chemically basic, and thus react with the aqueous solution of the pol3mieric acid. The acid/base reaction that takes place when powder and liquid components are mixed, transforms the paste to a rigid mass within ten to twenty minutes. The mechanistic details of this reaction, as well as the structure/property relations obeyed by the solid product obtained are not well known at this time. Supposedly, the reaction involves the formation of ionic crosslinks between... 

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