The complex CuII-N-benzoylglycine provides a convenient system to study weak exchange interactions between unpaired spins transmitted through a biologically relevant long chemical bridge. The molecule exists as a dimer with each CuII ion coordinated to five ligands, forming a distorted square-based pyramid. The only chemical connection between magnetically non-equivalent copper ions is a very long path comprising 17 diamagnetic atoms and a weak putative hydrogen bond. This interaction was studied using Electron Paramagnetic Resonance in single-crystal samples at 9.5 and 34.5 GHz and its magnitude was calculated as 4(1) mK. This value is discussed in terms of values obtained for similar paths in other model compounds and in proteins.
electron paramagnetic resonance; exchange interactions; model systems
