Synthesis, crystal structure and metamagnetic properties of a two-dimensional honeycomb network based on ferricyanide and (3,10-dimethyl-1,3,5,8,10,12-hexaazacyclotetradecane)nickel(II) building blocks†

Abstract

The 2-D bimetallic complex [NiL]₃[Fe(CN)₆]₂·9H₂O (L represents 3,10-dimethyl-1,3,5,8,10,12-hexaazacyclotetradecane) has been prepared and its structure and magnetic properties studied. The structure consists of cyano-bridged neutral Ni₃Fe₂ units. Each hexacyanoferrate(III) ion connects three nickel(II) ions using three cis CN^– groups and the remaining CN^– groups are terminal. The bridging cyanide ligands co-ordinate to the nickel ion in a trans fashion forming trans-NiL(NC)₂ moieties. The nine water molecules are situated between the 2-D layer and hydrogen bonded to the terminal CN^– ligands. Magnetic studies show that the complex displays a metamagnetic behaviour originating from intralayer ferromagnetic coupling and interlayer antiferromagnetic interaction. A long-range magnetic ordering over the lattice at T_c = 5 K is also observed.