A heterometallic nanosized tube {Fe[(CN)6]2[Co(LN3O2)]3}n and two of its lamellar polymorphous isomers

Abstract

Single crystals of three polymorphous compounds were synthesized started from two building blocks, [Fe(CN)₆]³⁻ and [Co(L_N3O2)]²⁺ (L is a Schiff-base macrocyclic ligand derived from the condensation of 2,6-diacetylpyridine with 3,6-dioxaoctane-1,8-diamine) using a crystallization condition control. All three compounds consist of electroneutral skeletons made up of Fe₆Co₆ twelve-metal ring units, which is the smallest enclosed circle in their structures: 1 is comprised of 1D nanometer-diameter tubes possessing nanometer-sized tunnels (0.58 nm × 0.74 nm); 2 and 3 are based on piled-up 2D lamellar layers in the (6, 3) and (4, 4) networks, respectively. Magnetic studies indicate ferromagnetic interactions between cyanide-bridged cobalt(II) and iron(III) in each compound.