Atomic Layer Deposition of Rhenium–Aluminum Oxide Thin Films and ReO_x Incorporation in a Metal–Organic Framework

Methyltrioxorhenium (ReO₃Me) is introduced as the first rhenium atomic layer deposition (ALD) precursor and used to grow rhenium–aluminum oxide thin films in combination with trimethylaluminum (TMA–AlMe₃). The growth rate of the smooth Re–Al oxide films, with general stoichiometry Re_xAl_yO_3x, has been monitored by in situ quartz crystal microbalance (QCM) and ex situ ellipsometry, and found to be 3.2 Å/cycle. X-ray photoelectron spectroscopy (XPS) revealed the mixed valent composition of the film with Re­(III) species being the main component. In addition, ReO₃Me has been successfully used to deposit rhenium oxide in NU-1000, a mesoporous zirconium-based metal–organic framework (MOF). The metalated MOF was found to retain porosity and crystallinity and to be catalytically active for ethene hydrogenation.