Poly[bis(acetone)bis[μ‐4‐[(5‐chloro‐2‐oxidophenyl)diazenyl]‐3‐oxido‐ N ‐phenylnaphthalene‐2‐carboxamidato]sodium(I)ferrate(III)]

The title compound, [FeNa(C 23 H 14 ClN 3 O 3 ) 2 (C 3 H 6 O) 2 ] n , has a skeleton of an azo–Fe III anion complex with a sodium cation, used widely as a charge‐control agent (CCA) of the negative type in electrophotography. In the Fe III anion‐complex, the Fe III atom is coordinated by four carbonyl O atoms and two N atoms of the diazo groups from two azo ligands lying cis to each other. There are two N—H...O intramolecular hydrogen bonds between the NH group and the carbonyl O atom. In the crystal structure, there exists a sodium‐cation dimer bridged by the carbonyl O atoms at the periphery of the anion complex. An interesting aspect of this structure is that each sodium cation unites three different Fe‐anion complexes through the carbonyl O atom, generating a quasi‐two‐dimensional network parallel to the (001) plane. At the same time, the sodium cation accommodates two acetone molecules, linked through the carbonyl O atom.