Tuning the planarity of [2 × 2] grids

Abstract

New [2 × 2] metallogrids derived from a ditopic ligand with terminal salicylaldimine binding sites giving six-membered chelate rings have been structurally characterised in order to determine the effect of ring size variation on the planarity of the core M₄ unit. Both the Zn₄ unit of the grid formed from the neutral ligand and the Fe₄ unit of the grid formed from the doubly deprotonated ligand are very close to planar, despite considerable differences in the coordination spheres of the two metal ions and the difference in their oxidation states (Zn(II), Fe(III)).