Thermal properties of solid nickel(II) coordination compounds

Abstract

The paper deals with the chemical and physical factors influencing the stoichiometry of thermal decomposition of solid coordination compounds. Nickel(II) coordination compounds were used as examples : the problem of the relationship between the structure of the initial compound (and of its intermediates) and the stoichiometry of thermal decomposition is discussed; experimental conditions are shown to affect this decomposition, and the conceptions of the apparent and real stoichiometries of thermal decomposition are discussed. The results obtained may have a more general meaning.

Thermal decomposition of nickel(II) complexes under quasi-equilibrium conditions

“…Literature data show [5] that complexes of the type NiLaX2 (L= volatile monodentate ligand, X= anionic ligand) can exhibit rather different decomposition stoichiometries. Though the experimental conditions do not differ considerably, the results obtained by the various authors are different.…”

“…To investigate the bond strengths, it would be correct to consider the dissociation heats in the gaseous state AT ML.X2(g) 9 MX2(g) + nL(g) (5) AH(5) = AH(1) -AH subl. {ML.X2} + M-/subl.…”

Synthesis and thermal behaviour of 4,4′-bipyridyl and 2,4′bipyridyl complexes of Co(II), Ni(II) and Cu(II) thiocyanates

“…The conditions of thermal decomposition of thiocyanato complexes of Co(II), Ni(II) and Cu(II) with various organic N-donors have been studied by many authors [1][2][3][4][5][6][7][8][9][10]. The synthesis and physico-chemical properties (except the thermal behaviour) of thiocyanato complexes of these metals have been studied intensively, but only with 2,2'-bipyridyl (2-bipy) and other amines [I 1 -15].…”

Heterogeneous reactions of solid nickel(II) complexes. XVIII

“…The stoichiometry (stepwise character) of thermal decomposition of solid nickel(l I) complexes generally depends on various factors [1]: their crystal structure, the experimental conditions in the measurements, as well as the properties of the ligands (electronic and steric) and their mutual interactions. The position and nature of substituents in the ligands may play a great role; they influence the stereochemistry of the starting complexes (and also the products formed by decomposition) and moreover the stoichiometry of thermal decomposition.…”