Glossary: Introduction to inorganic chemistry

ammine. Compare with amine.

A metal ion complex containing ammonia as a ligand. The ammonia nitrogen is bound directly to a metal ion in ammines; amines differ in that the ammonia nitrogen is directly bound to a carbon atom.

chelate.

A stable complex of a metal with one or more polydentate ligands. For example, calcium complexes with EDTA to form a chelate.

coordination number.

The number of bonds formed by the central atom in a metal-ligand complex.

crystal field splitting energy. ()

Ligands complexed to a metal ion will raise the energy of some of its d orbitals and lower the energy of others. The difference in energy is called the crystal field splitting energy.

crystal field theory. crystal field.

The color, spectra, and magnetic properties of metal-ligand complexes can be explained by modeling the effect of ligands on metal's d orbital energies.

EDTA. ethylenediaminetetracetic acid; versine.

A polydentate ligand that tightly complexes certain metal ions. EDTA is used as a blood preservative by complexing free calcium ion (which promotes blood clotting). EDTA's ability to bind to lead ions makes it useful as an antidote for lead poisoning.

high spin complex. high-spin complex.

A metal-ligand complex with the same number of unpaired electrons as the uncomplexed metal ion. When a weak ligand complexes the metal ion, the crystal field splitting is small and the electrons can still occupy all of the d orbitals without pairing.

inorganic chemistry.

The study of inorganic compounds, specifically their structure, reactions, catalysis, and mechanism of action.

inorganic compound. inorganic. Compare with organic.

A compound that does not contain carbon chemically bound to hydrogen. Carbonates, bicarbonates, carbides, and carbon oxides are considered inorganic compounds, even though they contain carbon.

ligand.

1. In inorganic chemistry, a molecule or ion that binds to a metal cation to form a complex. 2. In biochemistry, a molecule that binds to a receptor, having a biological effect.

low spin complex. low-spin complex. Compare with high spin complex.

A metal-ligand complex with fewer unpaired electrons than the uncomplexed metal ion. When a strong ligand complexes the metal ion, the crystal field splitting is large and some electrons pair rather than occupying the higher energy d orbitals.

monodentate.

A ligand that has only one atom that coordinates directly to the central atom in a complex. For example, ammonia and chloride ion are monodentate ligands of copper in the complexes [Cu(NH₃)₆]²⁺ and [CuCl₆]²⁺.

polydentate. polydentate ligand.

A ligand that has more than one atom that coordinates directly to the central atom in a complex. Polydentate ligands are called chelating agents when two or more coordinating atoms are attached to the same metal ion in a complex. For example, EDTA or ethylenediaminotetracetic acid is a hexadentate ligand of calcium ion.

strong ligand. strong field ligand. Compare with weak ligand.

A ligand that causes a large crystal field splitting which results in a low-spin complex.

superoxide. superoxide ion.

A binary compound containing oxygen in the -½ oxidation state. For example, KO₂ is potassium superoxide, an ionic compound containing the superoxide ion, O₂^-.

water gas. blue gas; synthesis gas.

A fuel gas used in industrial synthesis of organic chemicals, and in welding, glassmaking, and other high-temperature industrial applications. Water gas made by passing steam over a bed of hot coal or coke. It consists mainly of of carbon monoxide (CO) and hydrogen (H₂), contaminated with small amounts of CO₂, N₂, CH₄, and O₂.

weak ligand. weak field ligand. Compare with strong field ligand.

A ligand that causes a small crystal field splitting which results in a high-spin complex.

Copyright © 1997-2010 by Fred Senese
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Last Revised 02/23/18.URL: http://antoine.frostburg.edu/chem/senese/101/inorganic/glossary.shtml