A linear cobalt(II) complex with maximal orbital angular momentum from a non-Aufbau ground state

Orbital angular momentum is a prerequisite for magnetic anisotropy, although in transition metal complexes it is typically quenched by the ligand field. By reducing the basicity of the carbon donor atoms in a pair of alkyl ligands, we synthesized a cobalt(II) dialkyl complex, Co(C(SiMe2ONaph)3)2 (where Me is methyl and Naph is a naphthyl group), wherein the ligand field is sufficiently weak that interelectron repulsion and spin-orbit coupling play a dominant role in determining the electronic ground state. Assignment of a non-Aufbau (dx2–y2, dxy)3(dxz, dyz)3(dz2)1 electron configuration is supported by dc magnetic susceptibility data, experimental charge density maps, and ab initio calculations. Variable-field far-infrared spectroscopy and ac magnetic susceptibility measurements further reveal slow magnetic relaxation via a 450–wave number magnetic excited state.

Source: ScienceNOW - December 20, 2018 Category: Science Authors: Bunting, P. C., Atanasov, M., Damgaard-Moller, E., Perfetti, M., Crassee, I., Orlita, M., Overgaard, J., van Slageren, J., Neese, F., Long, J. R. Tags: Chemistry, Materials Science, Online Only r-articles Source Type: news