Structural variations in metal complexes of a tertiary α-hydroxyoxime.

Despite the long term interest in hydroxyoximes as metal ion extractants, there is a lack of information on the possible coordination modes these ligands can assume, particularly in concert with a co-ligand. This is pertinent to the use of these extractants in synergistic systems, where a combination of extractants can achieve commercially useful results. We report here the structures of some metal complexes (M = Mn, Co, Ni, Cu, and Zn) with (1-hydroxycyclohexyl)-phenyl ketone oxime.

Lanthanoid "bottlebrush" clusters: remarkably elongated metal-oxo core structures with controllable lengths.

Large metal-oxo clusters consistently assume spherical or regular polyhedral morphologies rather than high-aspect-ratio structures. Access to elongated core structures has now been achieved by the reaction of lanthanoid salts with a tetrazole-functionalized calixarene in the presence of a simple carboxylate co-ligand. The resulting Ln19 and Ln12 clusters are constructed from apex-fused Ln5O6 trigonal bipyramids and are formed consistently under a range of reaction conditions and reagent ratios.

Recyclable calix[4]arene-lanthanoid luminescent hybrid materials with color-tuning and color-switching properties.

Inorganic-organic hybrid materials combine the properties of both components providing functionality with a wide range of potential applications. Phase segregation of the inorganic and organic components is a common challenge in these systems, which is overcome here by copolymerizing a metal-free calixarene ionophore and methyl methacrylate. A lanthanoid ion is then added using a swelling-deswelling procedure.

Luminescent lanthanoid complexes of a tetrazole-functionalised calix[4]arene.

p-t-Butylcalix[4]arene functionalised at the lower rim with two tetrazole moieties is found to be a useful receptor for lanthanoid cations. The luminescence of the resulting complexes can be controlled by addition of base, with emission achieved in the visible and infrared regions.