Ate complex
An ate complex in chemistry is a salt formed by the reaction of a Lewis acid with a Lewis base whereby the central atom increases its valence and gains a negative formal charge.. Often in chemical nomenclature the phrase ate is suffixed 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+, lithium tetramethylborate. This concept was introduced by Georg Wittig in 1958. Ate complexes are common for metals, including the transition metals, as well as the metallic or semi-metallic elements of group 2, 12, 13. They are also well-established for third-period or heavier elements of groups 14-18 in their higher oxidation states.
Ate complexes are the dual counterparts to onium compounds.
Lewis acids form ate ions when the central atom reacts with a donor, gaining one more bond and becoming a negative-charged anion.
Lewis bases form onium ions when the central atom reacts with an acceptor, gaining one more bond and becoming a positive-charged cation.
