Isolation of a planar π-aromatic Bi ring in a cobalt-based inverse-sandwich-type complex.

Monocyclic π-aromatic compounds are ubiquitous throughout almost all fields of natural sciences-as synthons in industrial processes, as ligands of metal complexes for catalysis or sensing and as bioactive molecules. Planar organocycles stand out through their specific way of overcoming electron deficiency by a non-localizable set of (4n + 2)π electrons. By contrast, all-metal aromatic monocycles are still rare, as metal atoms prefer to form clusters with multiply bonded atoms instead.

Unveiling the Werner-Type Cluster Chemistry of Heterometallic 4f/Post-Transition Metals: A {DyBi} Complex Exhibiting Quantum Tunneling Steps in the Hysteresis Loops and its 1-D Congener.

A new [DyBiOCl(saph)] () Werner-type cluster has been prepared, which is the first Dy/Bi polynuclear compound with no metal-metal bond and one of the very few Ln-Bi (Ln = lanthanide) heterometallic complexes reported to date. The molecular compound has been deliberately transformed to its 1-D analogue [DyBiO(N)(saph)] () via the replacement of the terminal Cl ions by end-to-end bridging N groups. The overall metallic skeleton of (and ) can be described as consisting of a diamagnetic {Bi} unit with an elongated trigonal bipyramidal topology, surrounded by a magnetic {Dy} equilateral triangle, which does not contain μ-oxo/hydroxo/alkoxo groups.

Dinuclear Rare-Earth β-Diketiminates with Bridging 3,5-Di-butyl-catecholates: Synthesis, Structure, and Single-Molecule Magnet Properties.

The dinuclear β-diketiminato complex [LClDy(μ-Cl)DyL(THF)] () (L = {2,6-PrCH-NC(Me)CHC(Me)N-2,6-PrCH}) was obtained by reaction of DyCl with KL in a molar ratio of 1:1 and used for the preparation of the mixed-ligand complex [LDy(μ-3,5-Cat)] () by salt metathesis reaction with 3,5-CatK (3,5-Cat -3,5-di--butyl-catecholate). Reactions of 3,5-CatNa with [LLnCl(THF)] (Ln = Dy, Y) ligated with the less bulky ligand L = {2,4,6-MeCH-NC(Me)CHC(Me)N-2,4,6-MeCH} afforded the mixed-ligand THF-containing complexes [LLn(μ-3,5-Cat)(THF)] (Ln = Dy (), Y ()). All new complexes were fully characterized, and the solid-state structures were determined by single-crystal X-ray diffraction.

A Nanosized {Ni } Cluster with a 'Flying Saucer' Topology Exhibiting Slow Relaxation of Magnetisation Phenomena at Both 15 K and 1.3 K.

A high-nuclearity {Ni} complex (1) with a unique 'flying saucer' motif has been prepared from the organic chelate, α-methyl-2-pyridine-methanol (mpmH), in conjunction with bridging azido (N ) and peroxido (O ) ligands. Magnetic susceptibility measurements revealed the presence of both ferro- and antiferromagnetic exchange interactions between the metal centres in 1, and the stabilization of spin states with appreciable S values at two different temperature regimes. The end-on bridging azido and alkoxido groups are in all likelihood the ferromagnetic mediators, while the η:η:μ-bridging peroxides most likely promote the antiparallel alignment of the metals' spin vectors, yielding an overall non-zero spin ground state for the centrosymmetric compound 1.