catalysant

Catalysant is a coined term used in discussions of catalysis to describe a chemical species that participates in a catalytic cycle in a dual role: as a catalyst and as an active reagent within the same system. In this concept, the catalysant lowers activation barriers through transient interactions with substrates while remaining capable of being regenerated, either within the catalytic loop or by a secondary step in the reaction network. The idea is to broaden the traditional view of a catalyst, which is usually considered unchanged at the end of a reaction, by emphasizing species that actively participate and then reappear in an active form.

Etymology and scope are informal; catalysant combines catalyst with the notion of acting or participating in the process. In practice, discussions of catalysants appear mainly in theoretical or speculative contexts, where researchers explore how turnover and efficiency might be enhanced by designing species that engage more closely with substrates or intermediates. The term is not widely adopted as a formal category in established chemical taxonomy, and many references treat catalysants as hypothetical or conceptual tools rather than a standard class of compounds.

Mechanistically, a catalysant is described as forming short-lived intermediates or covalent adducts with substrates that facilitate bond-making or bond-breaking steps, followed by regeneration of the active catalysant through internal rearrangements or auxiliary reactions. This framework is used to consider how catalytic efficiency could be improved in organocatalysis, metal-catalysis, or cooperative catalysis, without committing to a single, universally accepted mechanism.

See also: catalyst, co-catalyst, organocatalysis, homogeneous catalysis.