Crystal paramagnetic behaviour

Phase diagrams and crystal structures 74 3.4. Paramagnetic behaviour 103... 

Planar-octahedral equilibria. Dissolution of planar Ni compounds in coordinating solvents such as water or pyridine frequently leads to the formation of octahedral complexes by the coordination of 2 solvent molecules. This can, on occasions, lead to solutions in which the Ni has an intermediate value of jie indicating the presence of comparable amounts of planar and octahedral molecules varying with temperature and concentration more commonly the conversion is complete and octahedral solvates can be crystallized out. Well-known examples of this behaviour are provided by the complexes [Ni(L-L)2X2] (L-L = substituted ethylenediamine, X = variety of anions) generally known by the name of their discoverer I. Lifschitz. Some of these Lifschitz salts are yellow, diamagnetic and planar, [Ni(L-L)2]X2, others are blue, paramagnetic, and octahedral, [Ni(L-L)2X2] or... 

Diebold, A., Elbouadili, A., and Hagen, K.S. Crystal structures and solution behaviour of paramagnetic divalent transition metal complexes (Fe, Co) of the sterically encumbered tridentate macrocycles l,4,7-R3-l,4,7-triazacyclononane coordination numbers 5 (R = i-Pr) and 6 (R = /-Bu), Inorg. Chem. 39 (2000), 3915-3923. 

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