Tetranuclear Mn^II/Zn^II and Novel Azido‐Bridged Chair‐Shaped Heptanuclear Cd^II Compounds: The Effect of Metal Ion and Coordination Mode of the Azide Group on the Structure of the Products

Abstract

We report two tetranuclear compounds [MnL(N 3 )] 4 ( 1 ), [Zn 4 L 4 (N 3 ) 2 ][Zn(N 3 ) 4 ] · 3H 2 O ( 2 ) and a novel heptanuclear cluster [Cd 7 L 6 (N 3 ) 6 ](NO 3 ) 1.33 (N 3 ) 0.66 · 12H 2 O ( 3 ) where L is a hydrazone Schiff base ligand based on pyridine. The ligand acts as a negatively charged tetradentate N 3 O‐donor ligand and coordinates to the metal centers in the enolic form in 1 – 3 . However, in compound 2 , the ligand coordinated to the Zn II ion in the two different coordination modes. Metal centers in 1 and 2 , bridged by the organic ligand form tetranuclear metal organic complexes and the N 3 – anion acts as terminal ligand. In compound 3 , N 3 – acts as bridging ligand to the cadmium(II) centers, and form a rare heptanuclear cluster with an interesting chair conformation. The latter compound is a novel azido‐bridged chair‐shaped heptanuclear Cd II cluster that guides the formation of a water hexamer in the solid state. It acts as a robust binding block in the recognition of nitrate. The ability of the water hexamer to bind anions has been analyzed using DFT calculations and several computational tools.