{MnIII2LnIII2} (Ln = Gd, La or Y) butterfly complexes: Ferromagnetic exchange observed between bis-μ-alkoxo bridged manganese(III) ions

Exchange-Driven Slow Relaxation of Magnetization in NiII2LnIII2 (LnIII = Y, Gd, Tb and Dy) Butterfly complexes: Experimental and Theoretical Studies

The tetranuclear NiII2LnIII2 complexes, [{L′2{Ni(MeOH)(μ-OAc)}2(μ3-MeO)2Ln2}; LnIII = YIII (1), GdIII (2), TbIII (3), DyIII (4)] were prepared using a Schiff base ligand, H3L [H3L = 3-((2-hydroxy-3-methoxybenzylidene)amino)-2-(2-hydroxy-3-methoxyphenyl)-2,3-dihydroquinazolin-4(1H)-one, whereas {L′}3- is the...

Role of Coordination Number and Geometry in Controlling the Magnetic Anisotropy in FeII , CoII , and NiII Single-Ion Magnets

Since the last decade, the focus in the area of single-molecule magnets (SMMs) has been shifting constructively towards the development of single-ion magnets (SIMs) based on transition metals and lanthanides. Although ground-breaking results have been witnessed for Dy^III -based SIMs, significant results have also been obtained for some mononuclear transition metal SIMs. Among others, studies based on Co^II ion are very prominent as they often exhibit high magnetic anisotropy or zero-field splitting parameters and offer a large barrier height for magnetisation reversal. Although Co^II possibly holds the record for having the largest number of zero-field SIMs known for any transition metal ion, controlling the magnetic anisotropy in these systems are is still a challenge. In addition to the modern spectroscopic techniques, theoretical studies, especially ab initio CASSCF/NEVPT2 approaches, have been used to uncover the electronic structure of various Co^II SIMs. In this article, with some selected examples, the aim is to showcase how varying the coordination number from two to eight, and the geometry around the Co^II centre alters the magnetic anisotropy. This offers some design principles for the experimentalists to target new generation SIMs based on the Co^II ion. Additionally, some important Fe^II /Fe^III and Ni^II complexes exhibiting large magnetic anisotropy and SIM properties are also discussed.

Syntheses, structures and magnetic properties of novel tetrameric Ln2Mn2 and ring-like Ln4Mn4 clusters

Two series of heterometallic Ln–Mn clusters Ln2Mn2 and Ln4Mn4 were successfully synthesized in the presence of alcohol ligands, and the magnetic coupling interaction between metal ions were characterized by theoretical calculations.