Influence of the Ligand Field on Slow Magnetization Relaxation versus Spin Crossover in Mononuclear Cobalt Complexes

Authors: Fatemah Habib, Oana R. Luca, Veacheslav Vieru, Muhandis Shiddiq, Ilia Korobkov, Serge I. Gorelsky, Michael K. Takase, Liviu F. Chibotaru, Stephen Hill, Robert H. Crabtree, Muralee Murugesu - Angewandte Chemie International Edition 2013 cited by 211

The electronic and magnetic properties of the complexes [Co(terpy)Cl2 ] (1), [Co(terpy)(NCS)2 ] (2), and [Co(terpy)2 ](NCS)2 (3) were investigated. The coordination environment around Co(II) in 1 and 2 leads to a high-spin complex at low temperature and single-molecule magnet properties with multiple relaxation pathways. Changing the ligand field and geometry with an additional terpy ligand leads to spin-crossover behavior in 3 with a gradual transition from high spin to low spin.