Thermal Reactions of the Nickel(II) Complexes Containing 1-Phenyl-1,2-ethanediamine in the Solid Phase

Abstract

Nickel(II) complexes [Ni(phenen)2](ClO4)2 and [Ni(H2O)2(phenen)2]X2 (phenen=1-phenyl-1,2-ethanediamine, X=Cl, Br, or NO3) were prepared, and their thermal behavior was investigated in the solid phase. The nitrate showed a thermochromism consisting of two steps, violet→yellow→violet, which corresponds to a structural change from an octahedral diaqua complex to a square planar anhydride, and then to the octahedral dinitrato complex, respectively. Both the chloride and bromide were converted into the octahedral dianiono complexes by thermal deaquation-anation, retaining their octahedral configuration. However, no change was observed in the perchlorate, which is invariably square planar