The stoichiometry of mixed guest clathrates of [Ni(NCS)2(4-methylpyridine)4] (host) with methanol/4-methylpyridine and acetone/4-methylpyridine as well as the enthalpies of clathration and the thermokinetic course of the processes were investigated. Two different mechanisms of molecular inclusion are proposed: (I) simple competition for the same type of absorption sites with two methanol molecules substituting one of 4-methylpyridine in the solid inclusion compound; and (II) competitive absorption for two types of absorption sites of acetone and 4-methylpyridine. Partial molar enthalpies of clathration of the individual guests are derived and discussed. The thermokinetic course of the processes is also given. The analytical thermogravimetric procedure is described and the solid products of thermal decomposition of the clathrates and of the host complex were identified by using X-ray powder diffractometry.
Clathrateinclusion compoundinclusion of acetoneinclusion of methanol - enthalpy of