ON THE RELATIONSHIP BETWEEN THE STRUCTURES OF CU-II COMPLEXES AND THEIR CHEMICAL-TRANSFORMATIONS .15. THERMAL-DECOMPOSITION OF COMPOUNDS [CU(LL)(H2O)2](SO4) AND ACCOMPANYING STRUCTURAL-CHANGES

In the mutually isomorphous compounds [Cu(LL)(H2O)2](SO4), (LL = ethylenediamine (I), 2,2'-dipyridine (II) and 1, 10-phenanthroline (III)) are the water molecules cis-bonded to the central atom. The activation energies and preexponential factors gained for dehydration reactions of studied complexes do not differ very much from those, gained for dehydration of compounds with trans-bonded water molecules. The higher values of activation energy and preexponential factor were gained for compound I, the lower values for compound III. During dehydration, the originally non-coordinated oxygen atoms from sulfato groups are coordinated to the central atom from sulphato groups are coordinated to the central atom with expressive changes of the coordination polyhedra deformation and with expressive changes in crystal structures of I, and without noteworthy changes at II and III. From the dehydrated compounds the [Cu(phen)(SO4)] is the most thermally stable one, the [Cu(en)(SO4)] is decomposed at the lowest temperature. The decomposition proceeds under formation of different products, the splitting of LL is accompanied by the release of SO3. The formation Of CuSO4 was not observed.