Tetraaqua-1kappa4O-bis(epsilon -caprolactam-1kappa O)-mu-cyano-1:2kappa 2N:C-pentacyano-2kappa 5C-iron(III)yttrium(III), a novel cyano-bridged dinuclear complex.

Using caprolactam as a ligand, the novel title cyano-bridged yttrium(III)-ferricyanide complex, [Y(caprolactam)(2)(H(2)O)(4)Fe(CN)(6)] or [FeY(CN)(6)(C(6)H(11)NO)(2)(H(2)O)(4)], has been synthesized and structurally characterized. The Y atom is seven-coordinate and has approximately pentagonal-bipyramidal stereochemistry, with water molecules occupying apical positions. Of the five ligands in equatorial positions, one is the N-bound bridging cyano group, and flanking this are two O-bound caprolactam moieties, which are markedly inclined towards the bridged ferricyanide moiety such that they partially envelop it. Water molecules occupy the remaining two equatorial positions. The Y-N-C-Fe-C-N sequence of atoms lies on a crystallographic twofold axis and is therefore perfectly linear, which has not been observed previously in cyano-bridged bimetallic complexes.