Chemical bonding, application

Linus Pauling, The Nature of the Chemical Bond. Application of Results Obtained... 

Pauling, L. (1931) The nature of the chemical bond. Application of results obtained from the quantum mechanics and from a theory of paramagnetic susceptibility to the structure of molecules, J. Am. Chem. Soc. 58,1367-1400. 

I. Pauling, L. The Nature of the Chemical Bond. Application of Results Obtained from the Quantum Mechanics and from a Theory of Paramagnetic Susceptibility to the Structure of Molecules J. Am. Chem. Soc. 1931, 53, 1367-1400. 

Sherman, D. M. (1985b) SCF-Xa-SW MO study of Fe-O and Fe-OH chemical bonds Applications to the Mossbauer spectra and magnetochemistry of hydroxyl-bearing Fe3+ oxides and silicates. Phys. Chem. Minerals, 12, 311-14. 

The nature of the chemical bond. Application of results obtained from the quantum mechanics and from a theory of paramagnetic susceptibility to the structure of molecules. J. Am. Chem. Soc. 53 (1931) 1367—1400. SP 5 The nature of the chemical bond. II. The one-electron bond and the three-electron bond. J. Am. Chem. Soc. 53 (1931) 3225—3237. SP 6 Interatomic distances in covalent molecules and resonance between two or more Lewis electronic structures. Proc. Natl. Acad. Sci. 18 (1932) 293—297. The additivity of the energies of normal covalent bonds. Proc. Natl. Acad. Sci. 18 (1932) 414-416. (Linus Pauling and Don M. Yost). 

In the second half of the nineteenth century, physical chemistTy developed as a well-defined subject, consisting of thermodynamics, kinetics, and transport processes, and mainly dealing with bulk properties and continuum models. When quantum mechanics was discovered in 1925, paving the way for modem molecular physics, this subject was less well received by the chemists. Partly this was due to the morass of equations and calculations one sinks into, just to get insight into such a simple concept as the chemical bond. Application of quantum methods in chemistry was pioneered by people like Henry Eyring, Linus Pauling, Robert Mulliken, Per-Olov Lowdin, Bjorn Roos, and many others. Most of these scientists called themselves quantum chemists. ... 

Chromium is able to use all of its >d and As electrons to form chemical bonds. It can also display formal oxidation states ranging from Cr(—II) to Cr(VI). The most common and thus most important oxidation states are Cr(II), Cr(III), and Cr(VI). Although most commercial applications have centered around Cr(VI) compounds, environmental concerns and regulations ia the early 1990s suggest that Cr(III) may become increasingly important, especially where the use of Cr(VI) demands reduction and incorporation as Cr(III) ia the product. 

EXAFS is a nondestructive, element-specific spectroscopic technique with application to all elements from lithium to uranium. It is employed as a direct probe of the atomic environment of an X-ray absorbing element and provides chemical bonding information. Although EXAFS is primarily used to determine the local structure of bulk solids (e.g., crystalline and amorphous materials), solid surfaces, and interfaces, its use is not limited to the solid state. As a structural tool, EXAFS complements the familiar X-ray diffraction technique, which is applicable only to crystalline solids. EXAFS provides an atomic-scale perspective about the X-ray absorbing element in terms of the numbers, types, and interatomic distances of neighboring atoms. 

The discovery of the ci-helix structure was only one of many achievements that led to Pauling s Nobel Prize in chemistry in 1954. The official citadon for the prize wa.s for his research into the nature of die chemical bond and its application to die elucidadon of the structure of complex substances. ... 

On the other hand, fluorine s high electronegativity and its ability to form mostly ionic chemical bonds, provide materials with several useful properties. First, compared to oxides, fluoride compounds have a wide forbidden zone and as a result, have low electroconductivity. In addition, fluorides are characterized by a high transparency in a wide optical range that allows for their application in the manufacturing of electro-optical devices that operate in the UV region [42,43]. 

At the same time, the relatively low energy and ionic character of the chemical bonds between metal and fluorine cause some difficulties in the application of fluoride compounds. First, fluorides typically have a tendency towards thermolysis and hygroscopicity. In addition, fluoride compounds usually display relatively low temperatures of electrostatic and magnetic ordering. 

Our explanation of chemical bonding is of value only if it has wide applicability. Let us examine its usefulness in considering the compounds of the second-row elements, beginning with fluorine. 

The initial set of experiments and the first few textbook chapters lay down a foundation for the course. The elements of scientific activity are immediately displayed, including the role of uncertainty. The atomic theory, the nature of matter in its various phases, and the mole concept are developed. Then an extended section of the course is devoted to the extraction of important chemical principles from relevant laboratory experience. The principles considered include energy, rate and equilibrium characteristics of chemical reactions, chemical periodicity, and chemical bonding in gases, liquids, and solids. The course concludes with several chapters of descriptive chemistry in which the applicability and worth of the chemical principles developed earlier are seen again and again. 

Daudel, R., Brion, H., and Odiot, S., J. Chem. Phys. 23, 2080, Localizability of electrons in atoms and molecules—application to the study of the notion of shell and of the nature of chemical bonds." Decomposition of the space of an electronic system into small parts where there is a very large probability of finding one and only one electron of a given spin. Discussion of the positional correlation between only one sort of spin, not that of two sorts of spin. 

The information contained in ESCA (Electron Spectroscopy for Chemical Analysis) spectra [331] makes the method particularly suitable for determinations of surface compositions, chemical bonding of surface atoms and changes which occur at solid surfaces during reaction [312], Applications of this technique to the study of reactions of and between solids are awaited with interest. 

Application of ligand field spectroscopy to problems of chemical bonding in solids. D. Reinen, Angew. Chem., Int. Ed. Engl., 1971,10, 901-909 (30). 

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