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Macroscale synthesis

Both 2- and 4-(26) yielded the saturated hydrodimers using Baizer s procedure.54 Utley and Caddy confirmed the macroscale synthesis of the hydrodimer of 4-(26).55 4-Styrylpyridine gave the isomeric meso and dl hydrodimers (28) as did the p-tolyl and p-anisyl analogs of styrylpyridine.56... [Pg.180]

It is in the synthesis of organometallic complexes that the metal-atom technique shows its greatest utility. From metal vapors, many complexes may be synthesized on a macroscale that are difficult, if not impossible, to prepare by standard, wet-chemical techniques (64, 65). In this section, we shall illustrate the vast potential that the method has in this area, although, to be sure, it is evident throughout this entire review. [Pg.145]

Volume 18 of Advances in Chemical Engineering returns to the dominant twin themes of modern chemical engineering the microscale of molecules and small particles, and the macroscale of entire engineering systems, of analysis and synthesis. [Pg.274]

There are three chapters in this volume of Advances in Chemical Engineering. The chapter, Analysis and Synthesis of Resilient Heat Exchanger Networks by Colberg and Morari of Caltech, is concerned with the development of new generic tools. It provides an overview on the macroscale design of systems that are resilient and flexible to uncertainties and variations in system variables, such as flow rates and fouling of heat exchanger surfaces. [Pg.336]

Microreactors offer a radical alternative platform for chemical synthesis, normally undertaken in macroscale flasks [68-70]. When reactions in microcapillary-scale reactors are compared with those in flask-scale batch reactors, they have been shown to offer yield, rate or selectivity advantages in a diversity of reactions schemes including carbonylative cross-coupling of arylhalides to secondary amides [32],... [Pg.50]

Microreactors provide a safe means by which reactions, including multistage schemes, can be undertaken where, otherwise, products involving unstable intermediates may be formed. This is exemplified by Fortt who showed that for a serial diazonium salt formation and chlorination reaction performed in a microreactor under hydrodynamic pumping, significant yield enhancements (15-20%) could be observed and attributed them to enhanced heat and mass transfer [77]. This demonstrates the advantage of microreactor-based synthesis where diazonium salts are sensitive to electromagnetic radiation and static electricity, which in turn can lead to rapid decomposition. Microreactors facilitate the ability to achieve continuous-flow synthesis, which is often not possible with conventional macroscale reactors and batch production. [Pg.51]

Recently reported meso- and macroscale self-assembly approaches conducted, respectively, in the presence of surfactant mesophases [134-136] and colloidal sphere arrays [137] are highly promising for the molecular engineering of novel catalytic mixed metal oxides. These novel methods offer the possibility to control surface and bulk chemistry (e.g. the V oxidation state and P/V ratios), wall nature (i.e. amorphous or nanocrystalline), morphology, pore structures and surface areas of mixed metal oxides. Furthermore, these novel catalysts represent well-defined model systems that are expected to lead to new insights into the nature of the active and selective surface sites and the mechanism of n-butane oxidation. In this section, we describe several promising synthesis approaches to VPO catalysts, such as the self-assembly of mesostructured VPO phases, the synthesis of macroporous VPO phases, intercalation and pillaring of layered VPO phases and other methods. [Pg.35]

In macroscale paired electrochemical synthesis it was found that a correct choice of reactor design and good mixing conditions favor the production of cyclopropane adduct over that of the dihydrodimers ... [Pg.929]

In the case of macroscale reactions of Ga atoms with alkyl halides, a useful synthesis of R2GaI was developed ... [Pg.295]

Many of the macroscale and mesoscale P2 approaches rely on a molecular-level understanding of chemical and physical process at the microscale. For example, the synthesis of new catalysts to achieve higher yields with less wastes relies on a fundamental understanding of surface chemistry. There are a large number of methods available for undertaking P2 at the microscale via the molecular-level redesign of chemical products and processes. In line with the emergence... [Pg.120]

Similarly, the design of macroscale vapor synthesis reactions in liquids can benefit from adaptations of the techniques of cryogenic matrix isolation for studies in fluids.(33,34) For example, a significant development in the field of VS has been the discovery by Klabunde and co-workers(35) of "solvated" metal atoms for use in the preparation of uni-and bimetallic supported catalysts. It is worth examining the subject of solvated atoms in a little detail to reveal something about them and to introduce the microscale VS technique in thin, quiescent liquid films. [Pg.173]

Darwinian evolution is kept in motion by a continual succession of newly arising variation and its modification by natural selection. The search for active substances proceeds through multiple-component simultaneous procedures, in which a restricted variant population is prepared on a microscale by a combinatorial strategy, to be subjected to the new form of selection, that is, collective screening. After a successfully applied unnatural selection of a particular variant with the desired properties, synthesis on a macroscale can take place. In Section 1.4.2.2.1 a static variation is going to be prepared and screened for anti-inflammatory... [Pg.30]

The use of microreactor technology for polymer chemistry presents an interesting alternative to conventional processing methods, in both batch and macroscale continuous flow. Microreactors offer a better process control of many exothermic polymerization processes, leading to increased product quality such as narrower polydispersity, and they allow for the synthesis of novel polymeric materials for a range of new applications. [Pg.331]


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See also in sourсe #XX -- [ Pg.173 ]




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