Inclusion compounds as sources of activated mixed oxides

About the thermal decomposition of tetracyanocomplexes

“…In the crystals, the stabilizing influence decreases from the inner to the outer layers, which could be observed also in our experiments in the testing of the weathering of our products. If one of the metal ions is in another oxidation state, (Ag(I) or Co(I/I), then if used in the preparation together with the [Ni(CN)4] 2-they tend to form an ionic, hydrated compound [ 18,25] and often the nickel and silver change positions. In both complexes some morphological changes have been observed [ 13,14,18] after heating to partial degradation, similarly to the intermediates of the clathrate.…”

“…After forming the layered structure, the appearance of the intermediates is progressively changing to a more rectangularly fluted appearance in the outer and inner areas. [6]) have been dealt with in previous papers [13,14,18,19]. We may find less often such destruction in Cu(NH3)aNi(CN)4.H20 or, in the case of Ni(en)2Ni(CN)4.2.4H20 a total collapse into an amorphous mass follows.…”

“…Some gas-chromatographic experiments [ 13,16,17] have revealed these properties of tetracyano-complex clathrates. In the case of pyridine or dioxane, some tendency to the substitution of the ligand B by the liberating G was observed -without the possibility to liberate them in a non-destructive way by heating the host.…”

“…Little thermal effects may influence the formation of at least a part of weathered products. They differ in morphology and properties from the products obtained by a regulated heating in shorter time intervals [13]. In the former case the spontaneous reaction course exhibits an irreversible character from the beginning, in the latter the topochemical reactions, show reversible character up to their 'temperature of conversion -tconv' [ 13], where the destruction of the host unit begins.…”

“…After storing for one year in the laboratory in a reaction bottle, the electron micrographs of the samples showed the presence of a portion of leaflets different from the original crystalline products. By a regulated heating of the same compounds (changing the heating rate from 3 to 6~ min-1), products were obtained with a compact form, with different proportions of 'scarred' areas on the surface [13,14]. The same or similar course could be observed also for the compounds Ni(NH3)2Ni(CN)a.2C6H6 and Cd(en)3Ni(CN)a-2C6H6 [ 15]: the first step of the topochemical destruction reactions was accompanied by the diffusion of the included species.…”