Structures and Magnetostructural Correlation of Two Desolvated Polymorphs of Ferrimagnetic <i>meso</i>-Tetrakis(4-chlorophenyl)porphinatomanganese(III) Tetracyanoethenide, [MnTClPP]⁺[TCNE]^•−

The structures of two polymorphs of [MnTClPP][TCNE] have been determined by Rietveld refinement of the X-ray powder diffraction method. Samples were prepared by thermolysis of the toluene and CH2Cl2 solvates, [MnTClPP][TCNE]·2Sol (Sol = PhMe, CH2Cl2). The desolvated structures are similar to their solvates, consisting of alternating stacks of the molecular donor and acceptor. Among the four structures, the largest changes are observed for the dihedral angle between the mean Mn(N4)TPP and [TCNE]•− planes, and the Mn−(N−C)TCNE angle. A magnetostructural correlation between the intrachain coupling and both the dihedral angle between the mean Mn(N4)TPP and [TCNE]•− planes and Mn−(N−C)TCNE angles is observed. This is in accord with the intrachain coupling arising from the overlap of MnIII dz2-like singly occupied molecular orbital (SOMO) and the z component of the [TCNE]•− π* (πz*) SOMO, which increases with decreasing dihedral angle between the mean Mn(N4)TPP and [TCNE]•− planes and Mn−(N−C)TCNE angle.