A new family of {Co4Ln8} metallacrowns with a butterfly-shaped structure. Issue 7 (27th June 2019) - Zhang, Hong-Gang
Abstract : A series of cobalt–lanthanide metallacrowns (MCs) {CoIII4Ln8 } (Ln = Dy 3+ 1, Ho 3+ 2 and Tm 3+ 3 ) based on pyrazinehydroxamic acid (H2 pyzha) and pyrazinic acid (Hpyzic) ligands have been synthesized. Abstract : A series of cobalt–lanthanide metallacrowns (MCs) {CoIII4Ln8 } (Ln = Dy 3+ 1, Ho 3+ 2 and Tm 3+ 3 ) based on pyrazinehydroxamic acid (H2 pyzha) and pyrazinic acid (Hpyzic) ligands have been synthesized. These isomorphous 3d–4f MCs contain two novel [12-MC-4] with –[Co–N–O–Ln]– connectivity to capture one Ln 3+ ion in the core of each MC. Two [12-MC-4] units are connected with the central Ln 3+ ions forming a butterfly-shaped structure. The existence of this structure leads to a new coordination mode of H2 pyzha which has never previously been reported. The magnetic properties of these MCs have been studied and the {CoIII4Dy8 } (1 ) was found to exhibit the single-molecule magnet (SMM) behavior.