Structure reinterpretation and determination of the clathrate nature of the compounds of the general formula MX(2)center dot 6Py

Unit cell parameters and space group (Ccca) were determined by X-ray diffraction analysis for II compounds of the general formula [MPy(4)X(2)]. 2y, (M = Cd, Co, Cu, Ni, Zn; X = Br, I, NO3, HCOO). It was found that these compounds, together with the Jive known compounds, form a large group of clathrates, in which [MPy(4)Y(2)] (host) complex molecules are packed with pyridine (guest) molecules held in the voids of the crystal framework by van der Waals forces. The results of the study and literature data are analyzed, and it is concluded that there are at least several dozens more clathrates of the molecular formula MX(2) . 6Py chat are known but not defined structurally.