A heterobimetallic cyanide-bridged CuIIFeIIICuII trimer. Synthesis, crystal structure and magnetic properties

A new Cu(II)–Fe(III)–Cu(II) heterobimetallic trimer (CuLα)2[Fe(CN)6]·ClO4 (where Lα = N-dl-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene), 1 has been synthesized. This compound can be viewed as a heterobimetallic trinuclear unit Cu(II)–Fe(III)–Cu(II), in which the magnetic centers are linked by cyanate bridges. The coordination polyhedra of metal (M) atoms can be described as a slightly distorted tetragonal pyramid (Cu) and an almost ideal octahedron (Fe) with nitrogen atoms in axial positions. In the structure hydrogen bonds can be found, which create chains along the crystallographic [0 1 0] axis and a two-dimensional net in the crystallographic (1 0 0) plane. The magnetic behavior of complex 1 has been investigated over the temperature range 1.8–300 K. Complex 1 displays ferromagnetic coupling inside the trinuclear core of CuFeCu.

A new 2D cyano-bridged trinuclear assembly, (CuLα)2[Fe(CN)6]·ClO4 (where Lα = N-dl-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene), has been synthesized and characterized by structural and magnetic methods. This compound can be viewed as a heterobimetallic trinuclear unit, in which the Cu(II)–Fe(III)–Cu(II) centers are linked by cyanate bridges. In the crystal lattice this trimer unit forms a chain structure, stabilized by hydrogen bonds to create a two-dimensional net. Complex 1 displays ferromagnetic coupling inside the trinuclear core of [CuFeCu] due to the orthogonality of the magnetic orbitals and the spin-polarization mechanism.Figure optionsDownload as PowerPoint slide