[Fe(OMe)2[O2CC(OH)Ph2]]12]: synthesis and characterization of a new member in the family of molecular ferric wheels with the carboxylatobis(alkoxo) bridging unit.

Abstract

New wheels: The 1:2 reaction of ferric nitrate with benzilic acid (Ph2C(OH)COOH) in methanol at pH≈4.0 results in the formation of a new member of the molecular ferric-wheels family with the carboxylatobis(alkoxo) bridging unit. The molecular structure of [{Fe(OMe)2[Ph2C(OH)COO]}12] (see picture) consists of a centrosymmetric ring of 12 FeIII atoms held together by 24 μ2-methoxide ligands and 12 1,3-bridging carboxylate ligands. The 12 metal ions are nearly coplanar and the ring size is ≈11.4 Å. The Mössbauer spectrum and magnetic susceptibility measurements are presented.