Solid-state materials reactivity

Boukherroub, R. Chemical reactivity of hydrogen-terminated crystalline silicon surfaces. Current Opinion in Solid State Materials Science 9, 66 (2005). 

Real solid-state materials are often structurally complex and there can be a large number of bands to be considered. In addition, for 2D or 3D materials it is practically impossible to examine ei (k) for all the regions of the BZ. Fnrthermore, inside the BZ the syimnetry is nsnally qnite low and there can be many avoided crossings between bands. Hence, althongh in principle one can always perform an orbital interaction analysis of several COs, a particnlar orbital of the repeat unit can be spread ont between several bands. Under snch conditions, it can be very difficnlt to single ont an orbital or gronp of orbitals responsible for the structure or properties of the solid. However, since after all, solids are very big molecnles, we shonldbe able to develop qnahtative arguments similar to those snccessfiiUy nsed in molecnlar chemistry to explain the structure, properties, or reactivity of sohds. 

The evolution of the chemistry of TMPOs and TMPROs parallels the contemporary interest in properties of inorganic solid state materials. These useful physicochemical properties, derived from molecular recognition, endow such materials with applications to sorption, catalysis, molecular electronics, and optical systems (299-303). Molecular recognition, in this sense of appropriate juxtapositions of functional groups for reactivity and cooperative electronic effects, is often related to the periodicity of the crystalline state. Such considerations render the goals of crystal engineering quite attractive (301). 

For periodic systems, an ad hoc partitioning of their absolute hardnesses into atomic contributions results in the definition of reactivity indices for such extended compounds [205] which proves useful in order to understand the chemical behavior of solid-state materials [206]. For example, the differing reactivities of various polymorphs of lithium aluminate may be rationalized in terms of their acid-base behavior [207], and the quantum-chemical explanation is in accordance with the principle of Le Chatelier. 

By contrast, CVD is a process in which gaseous precursors are reactively transformed into a thin film, coating or other solid-state material on the surface of a catalyst or substrate. It should be stressed that CVD is no longer limited to thin film growth this method is now the preferred route to generating fiber-optic preforms, " ... 

Garcia-Garibay, M. A., Chemical reactivity in organized media statistical entropy and information in crystals and enzymes, Curr. Opin. Solid State Material Sci., 3/4, 399,1998. 

The various studies of shock-modified powders provide clear indications of the principal characteristics of shock modification. The picture is one in which the powders have been extensively plastically deformed and defect levels are extraordinarily large. The extreme nature of the plastic deformation in these brittle materials is clearly evident in the optical microscopy of spherical alumina [85B01]. In these defect states their solid state reactivities would be expected to achieve values as large as possible in their particular morphologies greatly enhanced solid state reactivity is to be expected. 

Fig. 7.10. The solid state reactivity of shock-modified zirconia with lead oxide as studied with differential thermal analysis (DTA) shows both a reduction in onset temperature and apparent increase in reaction rate. The shock-modified material has a behavior much like the much higher specific surface powder shown in B (after Hankey et al. [82H01]).

The aim of the series is to present the latest fundamental material for research chemists, lecturers and students across the breadth of the subject, reaching into the various applications of theoretical techniques and modelling. The series concentrates on teaching the fundamentals of chemical structure, symmetry, bonding, reactivity, reaction mechanism, solid-state chemistry and applications in molecular modelling. It will emphasize the transfer of theoretical ideas and results to practical situations so as to demonstrate the role of theory in the solution of chemical problems in the laboratory and in industry. 

Isoindoles are reactive toward oxidizing agents, and precautions usually advocated in the preparation of these compounds to prevent their oxidation merit careful consideration. The end products of oxidation are most often colored, resinous materials of indeterminate structure. The oxidative reactions appear to be accelerated by light and occur much more rapidly in solution than in the solid state. In a separate but possibly related process, certain isoindoles undergo polymerization in the solid state to give resins which, according to... 

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