What is the coordination number?

Defined by Alfred Werner In 1893, the Coordination Number The term used in chemistry to indicate the number of bonds that has a central metal ion in a coordination compound. Coordination numbers range from two to 16, with four and six most common. Although they are usually used for transitional metal atoms in the compound, they can also refer to non -metallic substances. These atoms are usually transient metals, which are elements that react with halogens. Examples of temporary metals are iron, copper, gold and chrome.

Transition metals are listed in groups of three to 12 in the periodic table of elements. Their reactions with other substances are usually obvious because solutions and compounds are subject to color change. For example, iron (FECL) is usually green black, but when it dissolves in solution, it yellowed. On the contrary, halogens include fluorine, chlorine and iodine. They always have seven valence electrons or electrons capable of sharing bindings with other atoms.

connected to a metal ion is a ligand. Atom or molecule,Ligand can be neutral or negatively charged, anion. Ligands are usually halogens.

It is a ligand connection to the main metal ions that result in a coordination number. For example, AG Ag or silver is the ion of central metal. Two ammonia molecules, NH _{3 are attached to the silver atom atom, one on both sides of the atom. The plus brand in the chemical name shows that the compound is positively charged.}

Coordination compounds are often used as catalyts or substances that begin or change the speed of chemical reaction. The real compound can be positively charged, negatively charged or neutral. Compounds with coordination numbers can be referred to by a real number or geometric name that reflects both coordinationNumber and basic shape of the compound.

For example, a compound with a coordination number of two will be linear, so these compounds are called collinear. Colinear compounds are unusual in metals, but relatively common for non -metal. The three coordination numbers are called trigonal flat. They are rare, but they are found when ligands are particularly large. Tetrahedral compounds have four coordination numbers, while five are either trigonal bipyramidal or square pyramidal.