Magnetic Properties of Co(II) Complexes with Polyhedral Carborane Ligands

Abstract

In this work we present a computational analysis of a new family of magnetic Co(II) single-ion complexes with large magnetic anisotropy based on icosahedral and octahedral carborane ligands. In particular, we extend our previous computational work [Alcoba et al. Inorg. Chem. 57, 7763 (2018)] on mononuclear Co(II) complexes with 1,2-(HS)2-1,2-C2B10H10 and 9,12-(HS)2-1,2-C2B10H10 icosahedral o-carborane ligands to a larger set of complexes where the Co(II) ion is doubly chelated by those ligands and by other two positional isomers belonging to the 1,2-dicarba-closo-dodecaborane family. We also describe Co(II) complexes with octahedral ligands derived from 1,2- dicarba-closo-hexaborane and study the effects of replacing a thiol group by a hydroxy one in both polyhedral geometries, as well as the influence of the position of the carbon atoms. Analyzing the results for a total of 20 complexes, our results show that carborane-based Co(II) single-ion compounds present a distorted tetrahedral geometry, high spin ground states, and high values for the magnetic anisotropy parameters. We point out which of these would be suitable candidates to be synthesized and used as molecular magnets.