The encapsulation of [Cu(en)2]2+ (en=ethylenediamine) by a novel three-dimensional CuII–MoIV bimetallic porous coordination polymer containing zigzag-ladder structure

The neutral three-dimensional cyano-bridged bimetallic coordination polymer, {[Cu(en)2][Cu(en)][Mo(CN)8]}n·4nH2O (en=ethylenediamine), has been synthesized and characterized. X-ray study shows that the asymmetric unit of the three-dimensional Cu(II)–Mo(IV) polymeric assembly consists of two half [Cu(en)2]2+ cations, a [Cu(en)]2+ cation and a [Mo(CN)8]4− ion, together with four water molecules. The latter Cu site is coordinated by two N atoms from an en ligand and by three cyanides in a distorted square-pyramidal environment. The Cu(II) ions of the two [Cu(en)2]2+ cations on the centers of inversion reside in an elongated octahedral geometry, and one of the [Cu(en)2]2+ cations is encapsulated in a ‘box’ formed by two pairs of co-lateral Cu2Mo2(CN)4 12-membered macrocyclic units. The Mo(VI) atom is coordinated by eight cyanides in an irregular square antiprism. Five of these acting as bridging units connect the Mo and the three Cu atoms to form an infinite three-dimensional porous network containing a zigzag-ladder structure.