THERMAL-DECOMPOSITION REACTIONS OF NICKEL(II) COMPLEXES UNDER QUASI-EQUILIBRIUM CONDITIONS .1. STUDY OF THE RELATIONSHIP BETWEEN THERMAL PARAMETERS AND DEGREE OF DISTORTION OF THE COORDINATION POLYHEDRON OF THE COMPLEXES NIL4(NCS)2 (L = PIPERIDINE, PYRIDINE OR 3-ETHYLPYRIDINE)

The relationship between the thermal parameters (quasi-equilibrium decomposition temperature, activation energy and frequency factor) and the degree of the tetragonal distortion of the NiL4(NCS)2 complexes (L = piperidine, pyridine or 3-ethylpyridine) was studied. It was found that with increasing degree of tetragonal distortion of the coordination polyhedron of these complexes, the activation energy E(a) also increases while the decomposition temperature (determined by quasi-isothermal measurements) decreases. The reasons for these differences are discussed.