Crystal field theory

Crystal field theory (CFT) describes the breaking of degeneracies of electron orbital states, usually d or f orbitals, due to a static electric field produced by a surrounding charge distribution. This theory has been used to describe various spectroscopies of transition metal coordination complexes, in particular optical spectra (colors). CFT successfully accounts for some magnetic properties, colors, hydration enthalpies, and spinel structures of transition metal complexes, but it does not attempt to describe bonding. CFT was developed by physicists Hans Bethe and John Hasbrouck van Vleck in the 1930s. CFT was subsequently combined with molecular orbital theory to form the more realistic and complex ligand field theory (LFT), which delivers insight into the process of chemical bonding in transition metal complexes.

Octahedral molecular geometry

In chemistry, octahedral molecular geometry describes the shape of compounds with six atoms or groups of atoms or ligands symmetrically arranged around a central atom, defining the vertices of an octahedron. The octahedron has eight faces, hence the

Ligand field theory

Ligand field theory (LFT) describes the bonding, orbital arrangement, and other characteristics of coordination complexes. It represents an application of molecular orbital theory to transition metal complexes. A transition metal ion has nine valence

Nickel(II) fluoride

Nickel(II) fluoride is the chemical compound with the formula NiF2. Its is an ionic compound of nickel and fluorine and forms yellowish to green tetragonal crystals. Unlike many fluorides, NiF2 is stable in air

Eastville Workhouse

The Eastville Workhouse was a workhouse situated at 100 Fishponds Road, in Bristol, U.K. It was converted into a home for the elderly in the 1920s, and demolished to make way for housing in 1972

Dulas, Herefordshire

Dulas is a civil parish in the County of Herefordshire in England, 18 km south west of Hereford. There is no village named Dulas, as the parish consists mainly of scattered farms and dwellings. The major buildings within the parish are Dulas Court, a

Kennedy J. P. Orton

Kennedy J. P. Orton was a British chemist. Initially he studied medicine at St. Thomas' Hospital, but there he became interested in chemistry and moved to St. John's College, Cambridge. He then obtained a Ph.D. summa cum laude in Heidelberg under Karl von

Muriel Chapman

Muriel Catherine Canning Chapman was a British chemist. She was one of the first female chemists at the University of Oxford, having matriculated there in 1920, the first year that women were permitted to do so. She was awarded a B. Sc. in 1923. She had

Langoe Wapentake

Langoe Wapentake was one of the ancient divisions of the parts of Kesteven in the County of Lincolnshire. It was separated into two divisions, named First and Second. The First division consisted of the Parishes of Billinghay, Kirkby Green and Timberland

Albert Brydges Farn

Albert Brydges Farn was a British amateur entomologist, chiefly remembered nowadays for a letter he wrote on 1878 to Charles Darwin describing industrial melanism in the annulet moth and suggesting natural selection as the process involved in pale forms

Gunnar Karlsson

Gunnar Karlsson was an Icelandic historian. Gunnar shaped methodological teaching at the University of Iceland when he started working there in the seventies and wrote a number of textbooks in history for all school levels as well as other publications