Click chemistry as a route to the synthesis of structurally new and magnetically interesting coordination clusters: a {Ni} complex with a trapezoidal prismatic topology.

The synthesis of a new {Ni8} cluster bearing tetrazolate- and azido-bridging ligands, and supported by chelating α-methyl-2-pyridine-methanol (mpmH) groups, is described herein. The reported compound has a unique trapezoidal prismatic topology, resulting from an unexpected in situ click reaction between the MeCN reaction solvent and the N3- ions under mild, room-temperature conditions. Such a click chemistry approach to the preparation of 0-D compounds is relatively unexplored and represents a fruitful strategy for the synthesis of new coordination clusters and molecule-based magnetic materials.

Field-induced slow magnetic relaxation in the first Dy(iii)-centered 12-metallacrown-4 double-decker.

The reaction of Dy(O2CMe)3·xH2O and Ga(NO3)3·xH2O led to the isolation of (nBu4N)[GaDyIII(OH)4(shi)8] (1). The compound possesses a unique chemical structure enclosing the central magnetic DyIII ion between diamagnetic GaIII-based metallacrown 12-MC-4 ligands. The double-decker complex exhibits field-induced single-molecule magnet (SMM) behaviour with an effective energy barrier (Ueff) of 39 K (27.1 cm-1). Consistent with the observed slow relaxation of magnetization, theoretical calculations suggest a ground state mainly determined by |±11/2> in the easy axis direction.

{Ni4} Cubanes from enantiomerically pure 2-(1-hydroxyethyl)pyridine ligands: supramolecular chirality.

Homometallic {NiII4} cubane-like clusters with a rare chiral core have been prepared via the employment of enantiomerically pure 2-(1-hydroxyethyl)pyridine (Hmpm). Comparison with the achiral cubanes derived from the related 2-pyridinemethanol (Hpym) ligand reveals drastic structural changes as a consequence of the transfer of chirality from the ligands to the whole structure. Their magnetic properties have been related to the structural features of their cubane-type cores.

Slow relaxation of magnetization in a {Fe6Dy} complex deriving from a family of highly symmetric metallacryptands.

The synthesis and characterization of a new family of isostructural {Fe6Ln} complexes, (pipH)3{Fe6Ln(shiH)3(shi)6}·1.5 pip·xH2O (Ln = Gd (1), Dy (2), Tb (3) and Y (4), pip = piperidine, and shi3- = salicylhydroxamic acid) is reported. The resulting compounds possess an exceptionally unique structure of a metallacrown-like motif while the overall complexes feature more the structure of metallacryptates. Magnetic studies are reported and reveal that the {Fe6Dy} analogue belongs to the single-molecule magnet (SMM) family.

Structural and magnetic variations in tetranuclear Ni(II) clusters: the effect of the reaction solvent and ligand substitution on product identity.

Three structurally and magnetically different tetranuclear Ni(II) complexes have been isolated and magnetically characterized, emphasizing the effect of the reaction solvent and organic ligand substitution on the chemical identity of cluster compounds.

Structural aesthetics in molecular nanoscience: a unique Ni26 cluster with a 'rabbit-face' topology and a discrete Ni18 'molecular chain'.

The use of a previously unexplored Schiff-base ligand in Ni(II) carboxylate chemistry has afforded a Ni26 cluster with a record nuclearity that crystallizes with a unique 'rabbit-face'-like topology, and a Ni18 compound that adopts an unusual 'molecular chain' structure.