elektrontransfer

Elektrontransfer, or electron transfer, is the movement of an electron from a donor to an acceptor. It is a central process in redox chemistry, electrochemistry, photosynthesis, respiration, and many materials applications. Transfer can occur within a molecule (intramolecular) or between species (intermolecular). Two main mechanisms are outer-sphere transfer, where electron tunneling occurs without a direct chemical bond, and inner-sphere transfer, in which a ligand bridges the donor and acceptor to mediate the transfer.

The rate of electron transfer depends on thermodynamic driving force, reorganization of the surroundings, and electronic coupling between the participating centers. Marcus theory provides a framework, relating the rate to the free energy change (ΔG°), the reorganization energy (λ), and the electronic interaction. Depending on the system, transfer can be diffusion-controlled or governed by an activation barrier.

In biology, electron transfer chains shuttle electrons through a series of redox centers in processes such as photosynthesis and cellular respiration. In chemistry and materials science, electron transfer drives batteries, catalysis, sensors, and molecular electronics. It also governs corrosion and electrochemical synthesis.

Experimental approaches include cyclic voltammetry and other electrochemical methods to measure redox potentials and transfer rates, along with spectroscopic techniques and computational models to estimate coupling and reorganization energies.

See also redox reactions, electron transport chain, Marcus theory, and electrochemistry.