Rhenium(IV)–copper(II) heterobimetallic complexes: Synthesis, crystal structure and magnetic properties

Abstract

Two Re(IV)–Cu(II) heterometallic complexes {(CuL α)[ReCl 4(ox)]} n (where L α = N-meso-5,12-Me 2-7,14-Et 2-[14]-4,11-dieneN 4), 1, and (CuL β)[ReCl 4(ox)] (L β = N-rac-5,12-Me 2-7,14-Et 2-[14]-4,11-dieneN 4 N-rac-5,12-Me 2-7,14-Et 2-[14]-4,11-dieneN 4), 2, were synthesized. The [CuL 2+] macrocyclic cation is coordinated from above and below by [ReCl 4(ox)] 2− units through the chloro-ligands and creates a chloro-bridged heterometallic Re IV–Cu II one-dimensional zig-zag chain. Compound 2 can be viewed as a heterobimetallic dinuclear unit, in which the Re(IV)-Cu(II) centers are linked by an oxalato bridge. The magnetic behavior of 1 and 2 has been investigated over the temperature range 1.8–300 K. Compound 1 behaves like a ferrimagnetic {Re(IV)–Cu(II)} bimetallic, one-dimensional chain with intrachain antiferromagnetic coupling. Compound 2 shows a weak antiferromagnetic interaction within the [Re(IV)–Cu(II)] unit along with a strong single-ion anisotropy, D(Re) = −63 cm −1.