μ-Oxo-bis[(diethyl 6,17-dimethyldibenzo[a,h]-5,9,14,18-tetraaza[14]annulene-7,16-dicarboxylato)iron(III)] sesquihydrate

Abstract

The title compound (systematic name: μ‐oxo‐bis­{[4,15‐bis­(ethoxy­carbon­yl)‐5,14‐dimethyl‐2,7,13,17‐tetra­azatricyclo­[16.4.0.07,12]docosa‐3,5,7,9,11,13,15,18(1),19,21‐deca­ene‐2,17‐diido]iron(III)} sesquihydrate), [Fe2(C26H26N4O4)O]·1.5H2O, crystallizes in the monoclinic space group C2/c and has two iron centres which are coordinated by macrocyclic ligands with an N4 donor set. These iron centres are bridged by a μ‐oxo ligand, resulting in the formation of a dinuclear complex unit. The μ‐oxo ligand inter­acts with a water mol­ecule via strong hydrogen bonds. These solvent mol­ecules aggregate by additional hydrogen bonds, producing a tetra­nuclear aggregate. Towards the outer rim of the cavity formed by the carboxy­ethyl substituents attached to the tetra­aza‐annulene systems there are additional solvent mol­ecules. Due to much weaker hydrogen‐bond inter­actions, the latter are disordered and have site‐occupancy factors less than 1.