molecular orbital theory


Also found in: Acronyms, Wikipedia.

molecular orbital theory,

detailed explanation of how electrons are distributed in stable moleculesmolecule
[New Lat.,=little mass], smallest particle of a compound that has all the chemical properties of that compound. A single atom is usually not referred to as a molecule, and ionic compounds such as common salt are not made up of molecules.
..... Click the link for more information.
. In the simpler valence theory of the chemical bondchemical bond,
mechanism whereby atoms combine to form molecules. There is a chemical bond between two atoms or groups of atoms when the forces acting between them are strong enough to lead to the formation of an aggregate with sufficient stability to be regarded as an
..... Click the link for more information.
, each atomatom
[Gr.,=uncuttable (indivisible)], basic unit of matter; more properly, the smallest unit of a chemical element having the properties of that element. Structure of the Atom
..... Click the link for more information.
 in a molecule is assumed to retain its own electrons. Even when electrons are shared, as in the covalent bond, it is possible to identify which electron came from which atom. The molecular orbital theory, however, treats each electron as associated with the molecule as a whole. Just as a free atom has certain allowed electron orbits and energies, each molecule has its own allowed molecular orbitals. The orbitals give the probability of finding the electron at any point in space. Each orbital can hold a maximum of two valence electrons and the structure of the molecule is built up by filling the lowest energy orbitals first. The calculations involved are extremely complex, and only the simplest molecules can be treated exactly.
References in periodicals archive ?
Cooper of the University of Liverpool, Joseph Gerratt of the University of Bristol and Mario Raimondi of the University of Milan indicate that the "delocalized" electrons of molecular orbital theory are actually localized in deformed orbits about the individual carbon atoms.
Molecular Orbitals and Organic Chemical Reactions is both a simplified account of molecular orbital theory and a review of its applications in organic chemistry; it provides a basic introduction to the subject and a wealth of illustrative examples.
He describes chemical structures, symmetry, polymorphism and phase transitions, chemical bonding and lattice energy, the effective size of atoms, ionic compounds, molecular structure, molecular orbital theory and chemical bonding in solids, the element structures of the nonmetals, diamond-like structures, polyanionic and polycationic compounds, Zintl phases, packing of spheres in relation to metal structures, the sphere-packing principle for compounds, linked polyhedra, packing of spheres with occupied interstices, symmetry as the organizing principle for crystal structures, the physical properties of solids, and, gently, pitfalls and linguistic aberrations.
The sixth edition adds material on molecular orbital theory, biochemistry, and environmental chemistry.
of Paris-Sud) keeps the fact that organometallic chemistry is by definition interdisciplinary, especially in terms of its relationship to theoretical chemistry as he starts with the most elementary ideas of molecular orbital theory and leads the reader toward an understanding of the electronic structure, the molecular geometry, and, in some cases, the reactivity of transition metal complexes.

Full browser ?