A dodecanuclear metallamacrocycle having a multidentate bridging ligand in two different binding modes

Abstract

The reaction of Mn(OAc)₂·4H₂O with 2,6-dimethoxybenzoylsalicylhydrazide (H₃dmbshz) leads to a dodecanuclear manganese metallamacrocycle [Mn₁₂(dmbshz)₁₂(EtOH)₆], 1. The successive manganese centers are connected by the hydrazide N–N groups of the ligands in an alternating pentadentate binding mode, hexadentate binding mode. The alternation results in two alternating chelation modes around the metal centers, a tridentate–tridentate chelation mode and a bidentate–tridentate chelation mode. The metal ions in 1 are in a ⋯(A_AΔ_BC_AΛ_B)(A_AΔ_BC_AΛ_B)⋯ chiral sequence, the alternation of the chiralities expanding the cyclic ring system to a 36-membered dodecanuclear manganese metallamacrocyclic ring system with S₆ point group symmetry.