Solid State Chemical Synthesis

In this chapter synthesis of zinc ferrites, intermetallic compounds, and metal-oxides. 

The National Research Council Report Opportunities in Chemistry published in 1985 (called the Pimentel Report ) described a survey of the state of science and technology in chemistry and made recommendations concerning future opportunities. One of the recommendations proposed the following  

Certainly the ability to carry out chemical reactions at pressures of tens of GPa in times of a microsecond or less provides an opportunity to explore chemistry under extreme conditions as described by the report. Nevertheless, the conditions under which chemical reactions proceed under high pressure shock compression are complex and not well understood, and careful, systematic investigations are required to develop the ability to control and predict the reactions. The particular emphasis of work reported in this chapter is to study the solid state aspects of such processes. 

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Fig. 8.1. Shock-induced solid state chemical synthesis of a zinc ferrite has been studied over a wide range of temperature and pressure. The figure shows the location of conditions for which the reaction has been studied.

Intermetallics also represent an ideal system for study of shock-induced solid state chemical synthesis processes. The materials are technologically important such that a large body of literature on their properties is available. Aluminides are a well known class of intermetallics, and nickel aluminides are of particular interest. Reactants of nickel and aluminum give a mixture with powders of significantly different shock impedances, which should lead to large differential particle velocities at constant pressure. Such localized motion should act to mix the reactants. The mixture also involves a low shock viscosity, deformable material, aluminum, with a harder, high shock viscosity material, nickel, which will not flow as well as the aluminum. 

Shock-Induced Solid State Chemical Synthesis... 

The large-scale reproducible manufacture of minute, electronically-stable, single-crystal transistor junctions is a triumph of the elegant techniques of solid-state chemical synthesis. The sequence of steps is illustrated in diagrams (i)-(v). 

The manipulation of DNA has been revolutionized by a combination of enzymatic synthesis and solid-state chemical synthesis ( glue technology ). Two enzyme types are involved in DNA synthesis. 

Supramolecular assistance to covalent synthesis has become an important tool as an alternative synthetic route to prepare stereocontrolled compounds either in solution or in the solid state. Chemical synthesis performed in the solid state provides an interesting green alternative for the preparation of novel and traditional products. ... 

Solid-state chemical synthesis of nanoparticulate zirconia. Acto Materialia, 49, 4215-20. 

The general subject of solid-state chemical reaction in shock-wave compression, or shock-wave synthesis, has recently become an important part of the... 

Figure 5.3.9 (A) Simplified geometric model [46, 89] for the preparation of industrial Cu/ZnO catalysts comprising subsequent meso- and nanostructuring of the material from [56], In a first micro structure directing step (mesostructuring), the Cu,Zn coprecipitate crystallizes in the form of thin needles of the zincian malachite precursor, (Cu,Zn)2(0H)C03. In a second step, the individual needles are decomposed and demix into CuO and ZnO. The effectiveness of this nanostructuring step depends critically on a high Zn content in the precursor, which in zincian malachite is limited to Cu Zn ca. 70 30 due to solid-state chemical constraints [75]. Finally, interdispersed CuO/ZnO is reduced to yield active Cu/ZnO. (B) Chemical memory Dependence of catalytic activity in methanol synthesis on the conditions of the coprecipitation and aging steps, from [85].

Homoatomic sulfur cation are a fascinating class of compounds that maximize non-classical bonding in their solid state structures. Synthesis as well as quantum chemical calculations of these species are difficult but yet possible tasks and their structures and bonding interactions are now well understood. Structure and bonding of the in the solid state characterized sulfur... 

Solid-State Mechanochemical Synthesis Facile template-free solid-state mechano-chemical synthesis of highly branched PANI-NFs with coralloid tree-like superstrueture, via the oxidative polymerization of aniline hydrochloride with FeCl3 6H2O, has been demonstrated [194]. The synthetic yield ( 8%) was comparable to that of the solution interfacial polymerization method. Solid-phase mechanochemical synthesis of branched PANI-NFs was also achieved by using anhydrous FeCl3 as the oxidant [195]. 

These sets of parameters appear to be rather arbitrary and may have been established by empirical methods. It is the purpose of this chapter to describe some of the underlying solid state chemical principles which will allow us to systematize the complex phenomena of activation. A description of the resulting micromorphology will be followed by an analysis of the activated surfaces. The properties of the resulting gas-solid interface, as described by elemental and structural compositions and their changes with time, determine the usefulness of the activated catalyst. Finally, an empirical model of the active catalyst surface is presented which provides the basis for the discussion of the process of ammonia synthesis in terms of a comparison between the technical catalyst and model surfaces based on single crystals of iron. 

Table 3. Major linkers used in two-phase (solid state) oligosaccharide synthesis showing chemical structure of the linker, glycosylating agent, and removal methods used. 

This chapter presents detailed and thorough studies of chemical synthesis in three quite different chemical systems zinc ferrite, intermetallic, and metal oxide. In addition to different reaction types (oxide-oxide, metal-metal, and metal oxide), the systems have quite different heats of reaction. The oxide-oxide system has no heat of reaction, while the intermetallic has a significant, but modest, heat of reaction. The metal oxide system has a very large heat of reaction. The various observations appear to be consistent with the proposed conceptual models involving configuration, activation, mixing, and heating required to describe the mechanisms of shock-induced solid state chemistry. 

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