Synthesis - Genesis - Preparation

The widespread point of view with respect to PMs preparation is illustrated in the following quote (cited from Ref. 3) All catalysts that one can imagine must be grouped by their general characteristics mainly chemical, which determine the properties of particular stages of synthesis, genesis and formation of catalysts in framework of a chosen method of their preparation. ... 

The present paper focuses on the interactions between iron and titania for samples prepared via the thermal decomposition of iron pentacarbonyl. (The results of ammonia synthesis studies over these samples have been reported elsewhere (4).) Since it has been reported that standard impregnation techniques cannot be used to prepare highly dispersed iron on titania (4), the use of iron carbonyl decomposition provides a potentially important catalyst preparation route. Studies of the decomposition process as a function of temperature are pertinent to the genesis of such Fe/Ti02 catalysts. For example, these studies are necessary to determine the state and dispersion of iron after the various activation or pretreatment steps. Moreover, such studies are required to understand the catalytic and adsorptive properties of these materials after partial decomposition, complete decarbonylation or hydrogen reduction. In short, Mossbauer spectroscopy was used in this study to monitor the state of iron in catalysts prepared by the decomposition of iron carbonyl. Complementary information about the amount of carbon monoxide associated with iron was provided by volumetric measurements. 

A hemicalixarene precursor to the calixarenes has also been suggested for the genesis of the 6 (see ref 1, p. 56), but recent experiments may refute this possibility. A reaction employing the Organic Synthesis conditions for preparing 6 was monitored by GC and TLC which showed that at the end of the first step relatively little linear trimer and tetramer are present but that significant amounts of the linear hexamer have formed, suggesting that the immediate precursor for 6 is a pseudocalixarene (i.e. a linear hexamer) rather than a hemicalixarene (i.e. a pair of linear trimers). 

This essay deals not only with preparation (intuitive) and synthesis (planned) but also with genesis (programmed). Such (genetically and somatically regulated) programs have arisen through Darwinian evolution. A plan for a synthesis is devised by a synthetic chemist as designer and enacted by the synthetic chemist as molecule maker. How is a synthesis planned ... 

This survey describes how the chemistry of lithiated oxygen heterocycles has been fruitfully exploited, particularly over the last 10 years, for the preparation of more (stereodefined) functionalized derivatives and products derived from them. Also, how they have contributed to natural product synthesis and molecules of relevant pharmaceutical interest. The genesis of the reactive lithiated intermediates (especially a- and orf/io-lithiated (hetero)arylepoxides, -oxetanes and -tetrahydrofurans) requires a careful choice of the experimental conditions in terms of solvents and temperature in order them to be successfully intercepted by electrophiles. The study of the aggregation and solvation of certain chiral functionalized lithiated oxygen heterocycles has provided further hints about the factors affecting their configurational stability and... 

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