Knowledge Bank

Clathrates are ordered with respect to the host lattice, but are usually compositionally disordered with respect to the guest molecules filling the voids. The interaction between the guest and the host is weak. Complexes of the form $M2+(\gamma -picoline)4(ECN-)2$ with M = Mn, Fe, Co, Ni form clathrates with a large number of aromatic compounds, and provide an interesting crystalline medium for study of the spectroscope of the guest molecules. Raman and electronic spectra of clathrates with benzene and p-disubstituted benzenes as guest will be presented. The phonon and exciton. states will be discussed in terms of guest compositional disorder and guest-host interaction.