Structural anisotropy of cyanido-bridged {Co II9W V6} single-molecule magnets induced by bidentate ligands: towards the rational enhancement of an energy barrier

Abstract

Pentadecanuclear {Co^II₉[W^V(CN)₈]₆} clusters were combined with bidentate 2,2′-bipyridine N,N′-dioxide (2,2′-bpdo) ligands resulting in two distinct molecules, {Co₉W₆(2,2′-bpdo)₇} (cluster A) and {Co₉W₆(2,2′-bpdo)₆} (cluster B), capped by seven and six 2,2′-bpdo ligands, respectively. They crystallize within a single {Co₉W₆(2,2′-bpdo)₇}·{Co₉W₆(2,2′-bpdo)₆}·solvent (1) supramolecular network, and reveal single-molecule magnet behaviour with an enhanced energy barrier, a ΔE/k_B of 30.0(8) K, which was tentatively ascribed to seven-capped axially deformed cluster A.