High Uptake of ReO₄⁻ and CO₂ Conversion by a Radiation‐Resistant Thorium–Nickle [Th₄₈Ni₆] Nanocage‐Based Metal–Organic Framework

Abstract

Assembled from [Th₄₈ Ni₆ ] nanocages, the first transition-metal (TM)-thorium metal-organic framework (MOF, 1) has been synthesized and structurally characterized. 1 exhibits high solvent and acid/base stability, and resistance to 400 kGy β irradiation. Notably, 1 captures ReO₄ ^- (an analogue of radioactive ⁹⁹ TcO₄ ^- , a key species in nuclear wastes) with a maximum capacity of 807 mg g^-1 , falling among the largest values known to date. Furthermore, 1 can enrich methylene blue (MB) and can also serve as an effective and recyclable catalyst for CO₂ fixation with epoxides; there is no significant loss of catalytic activity after 10 cycles. Theoretical studies with nucleus-independent chemical shifts and natural bond orbital analysis reveal that the [Th₆ O₈ ] clusters in 1 have a unique stable electronic structure with (d-p)π aromaticity, partially rationalising 1's stability.