The facile and green preparation of novel materials that capture sulfur dioxide (SO2) with significant uptake at room temperature remains challenging, but it is crucial for public health and the environment. Herein, we explored for the first time the SO2 adsorption within microporous metal–organic cages using the palladium­(II)-based [ Pd6L8] ( NO 3 ) 36 tetragonal prism 1, assembled in water under mild conditions. Notably and despite the low BET surface area of 1 (111 m2 g–1), sulfur dioxide was found to be irreversibly and strongly adsorbed within the activated cage at 298 K (up to 6.07 mmol g–1). The measured values for the molar enthalpy of adsorption (ΔH ads) coupled to the FTIR analyses imply a chemisorption process that involves the direct interaction of SO2 with Pd­(II) sites and the subsequent oxidation of this toxic chemical by the action of the nitrate anions in 1. To the best of our knowledge, this is the first reported metal–organic cage that proves useful for SO2 adsorption. Metallosupramolecular adsorbents such as 1 could enable new detection applications and suggest that the integration of soft metal ions and self-assembly of molecular cages are a potential means for the easy tuning of SO2 adsorption capabilities and behavior.

Natural products are central to the organic synthesis field and attract immense interest due to their biological activity and wide industrial use. However, many suffer from poor aqueous solubility, instability under certain conditions, or bear complex composition, limiting their investigation and derivatization. Metal–organic cages (MOCs) are promising molecular receptors to solubilize in water, preserve, or transform natural products. This contribution features examples of MOCs that encapsulate naturally occurring compounds and synthetic congeners in aqueous media, protecting them from photodegradation or hydrolysis. We highlight cases of cages used as molecular vessels to promote chemical conversion and derivatization of natural substances. This review aims to provide an overview of the possibilities of using MOCs to bring about new properties and reactivity on natural products, offering methodological insights into cage operation for enhancing their activity and the engineering of further aqueous applications involving natural compounds, synthetic derivatives, and biomolecules.