donor (rus. донор) — (from Latin dono “I give”)  an atom or molecule, giving away an electron or electron pair to an acceptor.

Description

In a broad sense, a donor can give away different particles: an electron, proton, or a molecule. If the particle type is not specified it is deemed that the donated particle is an electron.

In physics, a donor is an impurity atom in a semiconductor, whose ionisation (as a result of thermal motion or external impact) leads to the appearance of an electron in the conduction band. For example, atoms of group V elements of the periodic system -P, As, Sb - are typical donors for Ge and Si. A point defect in the crystal lattice can also act as a donor.

In chemistry, the term "donor" primarily refers to a molecule or particle that can give away an electron pair to an acceptor and form a covalent donor-acceptor bond with it. In the generalised Lewis theory of acids and bases a donor is called a Lewis base. Typical donors are the atoms of nonmetals, especially O, N, as well as molecules, groups of atoms and negative ions, containing such atoms, for example, H2O, OH-, NH3, CN-. There exist also organic donors, molecules with low ionisation energy. They are able to give away an electron, but not electron pair, to an acceptor – a molecule with high electron affinity – and thus form a charge-transfer complex. These include, for example, metallocenes and organic -donors, such as tetrakis(dimethylamino)ethylene, bis(dimethylamino)phenyl, tetrathiofulvalenes and other unsaturated compounds with donor heteroatoms.

See also donor-acceptor interaction.

Author

  • Eremin Vadim V.

Source

  1. Physical Encyclopedic Dictionary (in Russian). — Moscow: Bol'shaja Rossijjskaja ehnciklopedija, 1995. — 928 pp.

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