First ‘Back-to-back’ Shaped Compartmental Ligand; Structural Characterization of a Tetranuclear Zinc(II) Complex in a Highly Flattened Form

Abstract Schiff-base condensation of 3,3′,5,5′-tetraformyl-4,4′-biphenyldiol, which was converted from 4,4′-biphenyldiol by a modified Duff reaction, and N,N-diethylethylenediamine in the presence of Zn(CH3CO2)2 followed by the addition of excess NH4PF6 gave a tetrazinc complex [Zn4(L)(µ-CH3CO2)4](PF6)2 (1), where L2− is a new ligand bearing four Schiff-base and two phenoxo-bridging moieties; structure of 1 was fully characterized by X-ray crystallography.