(a) Describe what is meant by an electron-deficient molecule.

Key Concepts

Electron Deficiency

Electron deficiency refers to a situation where a molecule has fewer electrons than required to achieve a stable electron configuration, typically resembling that of a noble gas. This often occurs in molecules with incomplete octets, leading to a tendency to accept electrons from other species, making them reactive and often acting as Lewis acids.

Lewis Acids and Bases

In the Lewis theory, acids are defined as electron pair acceptors, while bases are electron pair donors. Electron-deficient molecules often function as Lewis acids because they can accept electron pairs to complete their octet, facilitating various chemical reactions, including coordination and complex formation.

Stability and Reactivity

The stability of a molecule is closely tied to its electron configuration. Electron-deficient molecules are generally less stable and more reactive due to their incomplete valence shells. This reactivity can lead to the formation of new bonds as these molecules seek to achieve a more stable electronic state through interactions with electron-rich species.