Metathesis

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metathesis

[mə′tath·ə·səs]
(chemistry)
A reaction involving the exchange of elements or groups as in the general equation AX + BY → AY + BX.

Metathesis

 

one of the types of combinative sound changes, consisting of the transposition of sounds or syllables within a word.

Metathesis is found:

  1. In historical phonetic changes; for example, Russian lo- replaced Common Slavic ol- at the beginning of a word, as in Old Russian lodiia, “boat.”
  2. In the borrowing of words from other languages; for example, Ket garnitsa from Russian granitsa, “border.”
  3. In morphophonological alternations; for example, Georgian Su&qmetl, “fifteen” (not SquSmetl ), from qu&l, “five.”

Metathesis is especially common in substandard (colloquial or dialectal) speech; for example, Russian substandard perelinka for the standard pelerinka, “pelerine,” “cape,” by analogy with the prefix pere-. Metathesis may take place when sounds occur in close proximity (for example, Russian mramor from Latin marmor, “marble”) or when they occur at a distance (for example, Russian futliar from German Futteral, “case”). A special kind of metathesis is quantitative metathesis, whereby the quantitative characteristics (length) of sounds are exchanged, while their qualitative characteristics are retained (as in the Greek transformation of teos to teos).

Metathesis is used in literature for humorous effects (for example, S. Marshak’s poem “How Absentminded He Is”).

V. M. ZHIVOV

References in periodicals archive ?
Ring opening metathesis polymerization (ROMP) is a transition metal catalyzed polymerization technique belonging to a family of metathesis reactions that allow for carbon-carbon bond formation by double bond scrambling.
A major reason for the success of the metathesis reaction is the well-defined catalysts that have been developed for this reaction, such as ruthenium alkylidenes 1a and 1b.
We expect this highly flexible palette of catalysts to be useful for a wide variety of catalytic reactions that are catalyzed by a high oxidation state alkylidene species, and to be able to design catalytic metathesis reactions with a control that has rarely if ever been observed before," Schrock said.
Eight chapters are: introduction; basic chemical notions; polymerization of pristine oils and their fatty acids; monomers and polymers from chemically modified plant oils and their fatty acids; metathesis reactions applied to plant oils and polymers derived from the ensuing products; Thiol-ene and Thiol-yne reactions for the transformation of oleochemicals into monomers and polymers; Diels-Alder reactions and polycondensations applied to vegetable oils and their derivatives.