Ate complex
Encyclopedia
An ate complex in chemistry
is a salt
formed by reaction of a Lewis acid
with a base whereby the central atom increases its valence
. (Note that in this definition the meaning of valence is equivalent to coordination number
) Often in chemical nomenclature the phrase ate is suffix
ed to the element in question. For example, the ate complex of a boron
compound is called a borate
. Thus trimethylborane
and methyllithium react to form the ate compound Me4B-Li+. This concept was introduced by Georg Wittig
in 1958 The term is usually reserved for the complexes of metals in groups 2, 11 and 12. Similarly, Lewis bases form onium salts.
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
is a salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
formed by reaction of a Lewis acid
Lewis acid
]The term Lewis acid refers to a definition of acid published by Gilbert N. Lewis in 1923, specifically: An acid substance is one which can employ a lone pair from another molecule in completing the stable group of one of its own atoms. Thus, H+ is a Lewis acid, since it can accept a lone pair,...
with a base whereby the central atom increases its valence
Valence (chemistry)
In chemistry, valence, also known as valency or valence number, is a measure of the number of bonds formed by an atom of a given element. "Valence" can be defined as the number of valence bonds...
. (Note that in this definition the meaning of valence is equivalent to coordination number
Coordination number
In chemistry and crystallography, the coordination number of a central atom in a molecule or crystal is the number of its nearest neighbours. This number is determined somewhat differently for molecules and for crystals....
) Often in chemical nomenclature the phrase ate is suffix
Suffix
In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns or adjectives, and verb endings, which form the conjugation of verbs...
ed to the element in question. For example, the ate complex of a boron
Boron
Boron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...
compound is called a borate
Borate
Borates are chemical compounds which contain oxoanions of boron in oxidation state +3. The simplest borate ion, BO33−, has a trigonal planar structure. Other borates are made up of trigonal BO3 or tetrahedral BO4 structural units, sharing oxygen atoms...
. Thus trimethylborane
Trimethylborane
Trimethylborane is a toxic compound normally occurring as a gas that spontaneously catches fire in air. The formula is B3, which can also be expressed as Me3B, with Me representing methyl. Its melting point is -161.5 °C and boiling point is -20.2 °C.Vapour pressure is given by log P =...
and methyllithium react to form the ate compound Me4B-Li+. This concept was introduced by Georg Wittig
Georg Wittig
Georg Wittig was a German chemist who reported a method for synthesis of alkenes from aldehydes and ketones using compounds called phosphonium ylides in the Wittig reaction. He shared the Nobel Prize in Chemistry with Herbert C...
in 1958 The term is usually reserved for the complexes of metals in groups 2, 11 and 12. Similarly, Lewis bases form onium salts.