Ferroelastic-like transition and solvents affect the magnetism of a copper–organic radical one-dimensional coordination polymer

Abstract

The one-dimensional coordination polymers {[Cu^II(hfac)₂]₃(m-BNN)}_n·nCH₂Cl₂ (1·CH₂Cl₂, P) and {[Cu^II(hfac)₂]₃(m-BNN)}_n (1′, P2/n), hfac = hexafluoroacetylacetonate and m-BNN = meta-phenylene bis(nitronyl-nitroxide), were obtained from CH₂Cl₂ and CHCl₃, respectively. 1·CH₂Cl₂ is transformed to 1 at 335 K. Their magnetic susceptibilities differ in both magnitude and temperature dependence behavior. 1 and 1′ undergo a ferroelastic-like phase transition at 110 K and an unidentified one at 37 K. There is a subtle long relaxation of this ferroelastic-like ordered state.