A Manganese(III) Complex That Exhibits Spin Crossover Triggered by Geometric Tuning

Abstract

Room to expand: A rare example of thermal spin crossover in a MnIII complex is accompanied by elongation of the bonds to the equatorial N4 donor set upon warming (see scheme; Mn purple, N blue, O red), which is consistent with population of the d orbital. The spin crossover was observed for an N4(O−)2 donor set with axial oxygen donors, whereas only a temperature-independent high-spin state was observed with these donors in a cis arrangement.