New principles in metallomesogen structure–magnetism correlations

Whereas binuclear salicylaldimine complexes and their mononuclear parents are waxlike solids with long chain N-substituents, they are liquid crystalline (mesogenic) when such substituent chains are placed on both the ligand rings and the N-atoms. The structure of the non-mesogenic binuclears is determined via X-ray crystallography, and via the strength of magnetic coupling for the mesogenic ones. In the non-mesogenic binuclears the central metal environments have a marked distortion towards tetrahedral (>36°; scale 0° for planar, 90° for tetrahedral), while in the mesogenic ones, the stronger magnetic coupling indicates that this is closer to planar (25°).