Glossary

Key terms from KI 3231 — Transition Metals & Complex Chemistry

The minimum energy required for a chemical reaction to occur.

Change in disorder between reactants and the transition state. Negative values suggest an associative process.

Change in volume between reactants and the transition state; measured via pressure dependence of the rate.

Crystal Field Stabilization Energy. The energy gain from d-orbital splitting in a coordination complex.

A substitution pathway triggered by the deprotonation of a ligand by a strong base (OH⁻).

Relates reaction rate to temperature and activation parameters (ΔH‡, ΔS‡).

A complex that undergoes ligand substitution very slowly (t₁/₂ > 1 min).

A complex that undergoes ligand substitution rapidly (t₁/₂ < 1 min).

A theory describing the rates of electron transfer reactions, particularly outer-sphere pathways.

Rate-Determining Step. The slowest step in a reaction mechanism, which determines the overall rate.

The kinetic ability of a ligand to direct substitution to the position trans to itself.

A ligand that coordinates to two or more metal centers simultaneously, forming a bridge.

Electron density shifts from a metal d-orbital into the π* anti-bonding orbital of a ligand like CO.

The number of contiguous atoms in a ligand that are directly coordinated to the metal center.

A metal center inserts into a covalent bond, increasing its oxidation state and coordination number by 2.

The reverse of oxidative addition; two ligands couple and leave the metal, reducing OS and CN by 2.

A substance that ignites spontaneously upon contact with air.

The first synthesized organometallic complex, K[PtCl₃(η²-C₂H₄)].

A stability rule predicting that transition metal complexes with 18 valence electrons have closed-shell configurations.

An unsaturated ligand inserts into an adjacent M-alkyl or M-hydride bond, generating a vacant site.