Li, Na, K, Rb, and Cs have been intercalated into the twodimensional (2D) van der Waals material WO 2 Cl 2 , with K, Rb, and Cs intercalation being reported for the first time. The topochemical reaction of these alkali metals causes dramatic crystallographic, optical, and electronic changes to WO 2 Cl 2 . During the reaction with each of the alkali metals, WO 2 Cl 2 changes from a clear and transparent insulating phase to a blue partially intercalated species and finally to a lustrous bronze material. Upon intercalation, the host undergoes significant and systematic changes in interlayer spacing, as well as a 10 orders-of-magnitude change in resistivity from the base material to the intercalated bronze phase. Each of the alkali metals intercalates at a different rate and leads to specific changes in interlayer spacing and color of the bronze phase. This study provides a platform to study the electronic and optical properties of each of these new tungsten bronzes with a particular focus on lithium intercalation.

Aerobic oxidation of (tmeda)Fe(CH2tBu)2 in toluene or THF solution leads to the self-assembly of a magic-sized all-ferrous oxide cluster containing the Fe9O6 subunit and bearing organometallic and diamine ligands.

<div><div><div><p>Substoichiometric aerobic oxidation of the high-spin organometallic compound (tmeda)Fe(CH2tBu)2 (tmeda = N,N,N’,N’- tetramethylethylenediamine) in toluene or THF solution leads to the self-assembly of a magic-sized all-ferrous oxide cluster containing the Fe9O6 subunit and bearing organometallic and diamine ligands. Mössbauer studies of the cluster and the reference complex (tmeda)Fe(OCPh3)2 are consistent with the all-ferrous assignment, and magnetometry reveal considerable antiferromagnetic coupling between Fe atoms in the cluster and frustrated antiferromagnetic interactions between clusters in the solid state.</p></div></div></div>