Two heads are better than one: improving magnetic relaxation in the dysprosium metallocene upon dimerization by use of an exceptionally weakly-coordinating anion

Abstract

Partial metathesis between two weakly-coordinating anions in the archetypical dysprosium metallocene results in the first example of [BPh₄]⁻ as a bridging ligand in 4f metals, with a unique η₂,η₂:η₂,η₂-bridge. Magnetic susceptibility and relaxation dynamics studies along with ab initio calculations reveal improved slow relaxation of the magnetization in over its mononuclear congener, resulting in an energy barrier of 490 K/340 cm⁻¹ and waist-restricted hysteresis up to 6.5 K.