Molecular properties and reactions are controlled by electrons in the molecules. Electrons had been thought to be particles. Quantum mechanics showed that electrons have properties not only as particles but also as waves. A chemical theory is required to think about the wave properties of electrons in molecules. These properties are well represented by orbitals, which contain the amplitude and phase characteristics of waves. This volume is a result of our attempt to establish a theory of chemistry in terms of orbitals — A Chemical Orbital Theory.
The amplitude of orbitals represents a spatial extension of orbitals. An orbital strongly interacts with others at the position and in the direction of great extension. Orbital amplitude controls the reactivities and selectivities of chemical reactions. In the first paper on frontier orbital theory by Fukui the amplitude appeared in the form of its square, i.e., the density of frontier electrons in 1952 (Scheme 1). Orbital mixing rules were developed by Libit and Hoffmann and by Inagaki and Fukui in 1974 and Hirano and Imamura in 1975 to predict magnitudes of orbital amplitudes (Scheme 2) for understanding and designing stereoselective reactions.
Emerging Technologies of Text Mining: Techniques and Applications All around modern society, an enormous amount of strategic information is spread in many different presentation forms, like e-mail, formal and informal documents, historical reports, personal notes, Web pages, and so on. The access and transformation of this information in knowledge as a basis for decision making in the corporate world have become...
Using SANs and NAS
Data is the lifeblood of modern business, and modern data centers have extremely demanding requirements for size, speed, and reliability. Storage Area Networks (SANs) and Network Attached Storage (NAS) allow organizations to manage and back up huge file systems quickly, thereby keeping their lifeblood flowing. W. Curtis Preston's...
MOS 2010 Study Guide for Microsoft® Excel® Expert
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