Rotationsspektra

Rotationsspektra, also known as rotational spectra, are a type of molecular spectrum that arises from the rotational motion of molecules. These spectra are observed in the microwave and far-infrared regions of the electromagnetic spectrum. The rotational spectrum of a molecule provides information about its structure, including bond lengths, bond angles, and the presence of certain functional groups.

The rotational spectrum of a molecule is characterized by a series of closely spaced lines, each corresponding to a specific rotational transition. The energy difference between these transitions is typically very small, on the order of a few wavenumbers (cm^-1). The rotational spectrum of a molecule can be used to determine its rotational constants, which are related to the moments of inertia of the molecule.

Rotationsspektra are commonly observed using microwave spectroscopy, which involves passing microwave radiation through a sample of gas-phase molecules and detecting the absorption of radiation at specific frequencies. The resulting spectrum is a plot of the absorption intensity as a function of frequency, with each peak corresponding to a specific rotational transition.

Rotationsspektra are particularly useful for studying small molecules, such as diatomic and triatomic molecules, as well as linear and symmetric-top molecules. They are also useful for studying the dynamics of molecular rotation, including rotational relaxation and rotational diffusion.

In summary, rotationsspektra are a type of molecular spectrum that arises from the rotational motion of molecules. They provide valuable information about molecular structure and dynamics and are commonly observed using microwave spectroscopy.