Electron Acceptor
Because the process of oxidation is so widespread (fire, explosives, chemical synthesis, corrosion), the term oxidizing agent has acquired multiple meanings.
In one definition, an oxidizing agent accepts - or gains - electrons. In this context, the reducing agent is called an electron donor. A classic oxidizing agent is the ferrocenium ion +, which accepts an electron to form Fe(C5H5)2. Of great interest to chemists are the details of the electron transfer event, which can be described as inner sphere or outer sphere.
In more colloquial usage, an oxidizing agent transfers oxygen atoms to the substrate. In this context, the oxidizing agent can be called an oxygenation reagent or oxygen-atom transfer agent. Examples include − (permanganate), 2− (chromate), OsO4 (osmium tetroxide), and especially − (perchlorate). Notice that these species are all oxides, and are in fact polyoxides. In some cases, these oxides can also serve as electron acceptors, as illustrated by the conversion of − to 2−, manganate.
Read more about this topic: Oxidizing Agent