labile

(adjective)

A property of transient chemical species that enables rapid synthesis and degradation of substrates in biological systems.

Related Terms

Examples of labile in the following topics:

  • Reactions of Coordination Compounds

    • Complexes where the ligands are released and rebound rapidly are classified as labile.
    • Such labile complexes can be quite stable thermodynamically.
    • The lability of a metal complex also depends on the high-spin vs. low-spin configurations when such is possible.
    • Thus, high-spin Fe(II) and Co(III) form labile complexes, whereas low-spin analogues are inert.

  • Nucleophilic Substitution

    • Typically, strength of a leaving group's conjugate acid correlates with its lability.
    • The only criterion is that they are labile enough to be "pushed" away by the nucleophile.

  • Biomolecules

    • Metalloenzymes contain a metal ion bound to the protein with one labile coordination site.

  • Reactions of Alcohols

    • A similar reaction can be performed using PBr3 or SOCl2 (for bromination and chlorination, respectively) as agents to make the hydroxyl more labile.

  • Hydration of Alkynes and Tautomerism

    • Tautomers are defined as rapidly interconverted constitutional isomers, usually distinguished by a different bonding location for a labile hydrogen atom (colored red here) and a differently located double bond.

  • Reduction

    • The second example illustrates the lability of functional substituents alpha to the carbonyl group.

  • Electron Configuration of Cations and Anions

    • Electrons are rather labile, however, and an atom will often gain or lose them depending on its electronegativity.