Magnetic properties of closo-carborane-based Co(II) single-ion complexes with O, S, Se, and Te bridging atoms

OÑA, OFELIA B.; ALCOBA, DIEGO R.; MASSACCESI, GUSTAVO E.; TORRE, ALICIA; LAIN, LUIS; MELO, JUAN I.; OLIVA-ENRICH, JOSEP M.; PERALTA, JUAN E.

POLYHEDRON

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2020 vol. 176

0277-5387

We present a detailed computational analysis of a newly proposed family of Co(II) single-ion complexeswith large magnetic anisotropy. Starting from previously proposed structures based on oxy- and thio-bridged 1,2-dicarba-closo-dodecaborane and 1,2-dicarba-closo-hexaborane, we explore the substitutionof O and S bridging atoms by Se and Te atoms. Our calculations, based on CASSCF/NEVPT2 methods, showthat these substitutions also lead to some large magnetic anisotropy complexes. Particularly, one of theproposed single-ion Se-bridged Co(II) chelated by 1,2-dicarba-closo-dodecaborane has a calculated ani-sotropy parameter D 1⁄4 "144 cm"1, and a single-ion Se-bridged Co(II) chelated by 1,2-dicarba-closo-hex-aborane gives a calculated D 1⁄4 "133 cm"1. These large D values can be attributed in part to geometricdistortion from Td symmetry at the Co(II) ion caused by the ligand structure, and in part to the electriceffect of the Se atoms. Our results suggest that this strategy could be a feasible alternative to increasethe magnetic anisotropy of single-ion transition metal complexes.