sodiated

Sodiated is an adjective used in chemistry to describe a species that carries a sodium cation (Na+). In many contexts it refers to a molecular ion formed by association with sodium, most commonly seen as a sodiated adduct such as [M+Na]+ in mass spectrometry, but it can also describe organosodium compounds or sodium adducts of reactive intermediates.

In mass spectrometry, sodiated ions are frequently observed when samples contain sodium salts or trace sodium. Electrospray ionization and related techniques often generate [M+Na]+ ions, especially for molecules that ionize poorly as protons. The adduct adds 22.9898 Da to the neutral molecule, and the resulting spectra show distinctive isotopic and fragmentation patterns. The relative abundance of [M+Na]+ versus other adducts, like [M+H]+, can affect ionization efficiency and inform structural interpretation.

In synthetic chemistry, sodiated species describe systems where sodium forms part of an ionic pair with the molecule, such as sodium enolates, carbanions stabilized by Na+, or other organosodium reagents. These sodiated intermediates often exhibit distinct reactivity compared with their protonated or metal-free counterparts and are used to drive nucleophilic additions, condensations, or deprotonations under basic conditions.

Related terms include sodium adducts, lithiated or potassiated analogs, and the broader concept of metalation. The term “sodiated” emphasizes the presence and role of the sodium cation in the species’ structure, reactivity, or detection method.