metal-organic compounds
The title compound, tetraethylammonium dodeca--cyano-hexacyanotetrakis(ethylenediamine)tetracadmium(II)triferrate(III), (C8H20N)[Cd4Fe3(CN)18(C2H8N2)4], was prepared from a reaction mixture containing CdCl2, K3[Fe(CN)6], ethylenediamine (en) and [Et4N]Br in a 1:1:3:1 molar ratio. The crystal structure consists of a negatively charged three-dimensional framework of {[Cd(en)]4[Fe(CN)6]3}nn- anions, with [Et4N]+ cations located in the cavities of the framework. The Cd atom is octahedrally coordinated by one disordered chelating en molecule [mean Cd-N = 2.35 (3) Å] and four N-bonded bridging cyano groups [Cd-N distances are in the range 2.283 (2)-2.441 (2) Å]. There are two crystallographically independent [Fe(CN)6]3- anions in the structure and in each the Fe atom lies on a twofold axis. In the first [mean Fe-C = 1.941 (5) Å], all the cyano groups are bridging ligands, while in the second [mean Fe-C = 1.945 (2) Å], there are two terminal cyano ligands in trans positions. The Cd-N-C angles range from 128.6 (2) to 172.8 (2)°.