Thermal phase transition and decomposition of N-methyl-1,2-ethanediamine complexes of nickel(II) in the solid state

Abstract

[NiL₃]X₂H₂O(L = Nmethyl-1,2-ethanediamine; X− = Cl⁻ and Br⁻), [NiL₃]X₂ (X⁻ = NO₃⁻ and BF₄⁻) and [NiL₂X₂] (X⁻ = Cl⁻, Br⁻, NCS⁻, CF₃CO⁻₂ and CCl₃CO⁻₂) have been synthesized and their thermal studies have been investigated in the solid state. [NiL₃]Br₂, [NiL₂Br₂] (X⁻ = Cl⁻ and Br⁻ ), [NiLCl₂] and NiL_0.5Cl₂ have been synthesized pyrolytically in the solid state from their corresponding parent diamine complexes. [NiL₂X₂] (X⁻ = Cl⁻ and Br⁻) undergo endothermic reversible phase transition whereas [NiL₃]X₂ (X⁻ = N0⁻₃ and BF⁻₄) and [NiL₂(CF₃CO₂)₂] show endothermic time dependent reversible phase transition. All the complexes except NiL_0.5Cl₂ possess octahedral geometry. NiL_0.5Cl_0.5 possesses an unusually high magnetic moment (5.8 B.M. at 28 °C).