Elektronendonors

Elektronendonors (electron donors) are substances that donate electrons in redox reactions. In such reactions the donor is oxidized while the acceptor is reduced. The tendency of a species to donate electrons is described by its standard redox potential (E°); generally, donors with more negative E° values are stronger reducing agents.

Examples include inorganic metals such as zinc, iron, and magnesium, which readily donate electrons to metal ions or protons, hydride donors such as sodium borohydride, and organic reductants such as sulfides, sulfites, amines, and hydrosilanes under appropriate conditions. In electrochemistry and batteries, the electrode or chemical species that supplies electrons to the circuit acts as the donor.

In biology, electron donors supply reducing equivalents for energy conversion. Common biological donors include NADH and FADH2, which transfer electrons to the mitochondrial electron transport chain or photosynthetic systems. The identity and availability of donors influence reaction kinetics and overall redox balance.

Donor strength depends on solvent, pH, temperature, and the relative redox potentials of donor and acceptor. Practical use involves selecting a donor that reduces the target species without generating unwanted byproducts; in synthesis, this informs choice of reagents and reaction conditions. Understanding electron donors helps explain processes from catalysis to metabolism and energy storage.