A rotational spectrum of diatomic molecules refers to the spectrum of electromagnetic radiation emitted or absorbed by a molecule as it rotates around its axis. This type of spectrum is commonly used in molecular spectroscopy to study the structure, bonding, and dynamics of diatomic molecules.
A rotational spectrum of diatomic molecules is obtained by passing a beam of electromagnetic radiation through a sample of the molecule. As the molecule rotates, it will absorb or emit specific frequencies of radiation, which can be detected and analyzed to create a spectrum.
A rotational spectrum of diatomic molecules can provide information about the rotational energy levels and the moment of inertia of the molecule. From this, the bond length, structure, and other properties of the molecule can be determined.
The rotational spectrum of diatomic molecules is distinct from other types of molecular spectra, such as vibrational and electronic spectra, because it is highly dependent on the molecule's rotational motion. This type of spectrum is also highly sensitive to changes in the molecule's structure and bonding.
The study of rotational spectra of diatomic molecules has many practical applications, including in the fields of astronomy, atmospheric science, and chemical analysis. It is used to identify and study molecules in interstellar space, measure the composition of Earth's atmosphere, and determine the purity of chemical compounds.