Synthesis, structure and physical properties of a low dimensional compound.

The crystal structure of (μ-oxo)hexakis(cyanoacetato-κO,O')(cyanoacetato-κO)diaquatriiron(III) cyanoacetic acid shows the formation of trinuclear complexes in a hydrogen-bond network that bonds all the molecules in a 3D arrangement. For this complex, within whose clusters the whole magnetic interaction takes place, Fe Mössbauer spectroscopy shows that the Fe cations are in the S=5/2 state in the temperature range 2-295K. The asymmetric broadening of the absorption peaks below 80K is consistent with strong antiferromagnetic interactions between the metal spins. The magnetization measurements also show the antiferromagnetic character of the spin ensemble and an S=1/2 magnetic ground state typical of triangular systems with similar J between Fe-Fe pairs.