f-Block hydride complexes - synthesis, structure and reactivity

Complexes formed between the heaviest and lightest elements in the periodic table yield the f-block hydrides, a unique class of compounds with wide-ranging utility and interest, from catalysis to light-responsive materials and nuclear waste storage. Recent developments in syntheses and analytics, such as exploiting low-oxidation state metal ions and improvements in X-ray diffraction tools, have transformed our ability to understand, access and manipulate these important species. This perspective brings together insights from binary metal hydrides, with molecular solution phase studies on heteroleptic complexes and gas phase investigations. It aims to provide an overview of how the f-element influences hydride formation, structure and reactivity including the sometimes-surprising power of co-ligands to tune their behaviour towards a variety of applications.

Synthesis and Reactivity of Bis(silylene)-Coordinated Calcium and Divalent Lanthanide Complexes

Divalent lanthanide complexes of Eu (1) and Yb (2) coordinated by a chelating pyridine-based bis(silylene) ligand were isolated and fully characterized. Compared to the EuII complex 1, the YbII complex 2 presents a lower thermal stability, resulting in the activation of one SiII -N bond and formation of an YbIII complex (3), which features a unique silylene-pyridyl-amido ligand. The different thermal stability of 1 and 2 points towards reduction-induced cleavage of one SiII -N bond of the bis(silylene) ligand. Successful isolation of the corresponding redox-inert bis(silylene) CaII complex (5) was achieved at low temperature and thermal decomposition into a CaII complex (4) bearing the same silylene-pyridyl-amido ligand was identified. In this case, the thermolysis reaction proceeds through another, non-redox induced, mechanism. An alternative higher yielding route to 4 was developed through an in situ generated silylene-pyridyl-amine proligand.

Rare-earth metal hydrides supported by silicon-bridged boratabenzene fluorenyl ligands: synthesis, structure and reactivity

The first boratabenzene derivatives of rare-earth metal hydrides were synthesized, and their reactivity was studied.