Intercalation phases of TiS 2, 2HNbS 2, and 1TTaS 2 with ethylenediamine and trimethylenediamine: A crystal chemical and thermogravimetric study

The title compounds were prepared and chemicaly analyzed. Their crystal structures were determined from rotating crystal photographs. 1T-, 2H-, and two different 3R-polymorphs were observed. The thermogravimetric analysis, revealing two to four distinct steps for the phases derived from TiS ₂ and 2HNbS ₂, and only one to two smeared-out steps for those derived from 1TTaS ₂, proves the coexistence of strongly and weakly bound intercalate molecules. The first ones cannot be thermally deintercalated without chemical decomposition. The results are discussed within the framework of an ionic bonding model.