Molekulilineare

Molekulilineare is a term that is sometimes used to describe molecules with linear geometry, essentially translating to “linear molecule” or “linear molecular” in English. It is not a standard term in English-language chemistry, where the preferred expressions are linear molecule or linear molecular geometry. The exact usage of molekulilineare can vary by language and context, but it generally refers to molecules whose atoms lie along a straight line in their extended form.

A linear molecule is characterized by bond angles that sum to about 180 degrees along the chain of bonds. For a molecule with N atoms, linear geometry has two rotational degrees of freedom and 3N minus 5 vibrational modes. Common examples of linear molecules include diatomic species such as O2 and N2, and polyatomic but linear species such as CO2, C2H2 (acetylene), and HCN. Other linear examples include CO and OCS (carbonyl sulfide). Linear molecules can be contrasted with bent or angular (nonlinear) molecules, which have different bond-angle distributions and rotational-vibrational properties.

In spectroscopy and physical chemistry, linear molecules exhibit characteristic rotational and vibrational spectra that reflect their simple, slender geometry. Their modeling often uses the rigid-rotor approximation and distinct vibrational mode counts, which differ from nonlinear molecules. The term molekulilineare is primarily a language-dependent label; in English usage, describing these substances as linear molecules avoids ambiguity.

See also: linear molecule, molecular geometry, rotational spectroscopy, vibrational spectroscopy.