Bispidine-Based Copper(II) Coordination Polymers with Remarkable Dynamic Properties, Selective Volatile Organic Compounds Adsorption, and Exchange Capabilities.

This study presents novel bispidine-based Cu(II) coordination polymers (CPs) with remarkable dynamic properties, volatile organic compounds (VOCs) exchange, and selective adsorption capabilities. The coordination requirements of Cu(II) enable, as demonstrated by SC-XRD and Powder X-ray diffraction (P-XRD), the formation of either 1D ribbon-like (1-TCM and 1-HO) or 2D (1-MeCN) extended frameworks depending on the ability of the trapped solvents to interact as hydrogen bond (HB) donor with the metal's counterion. Hirshfeld Surface (HS) analysis and in situ VT SC- and P-XRD experiments reveal different interchain interactions in 1D vs 2D CPs. Solvent exchange experiments on both single crystals (SCs) and microcrystalline samples, set up to evaluate differences in the CPs' dynamic nature, confirm the drastic effect of CP dimensionality. Additionally, an amorphous desolvated phase 1-Amorph was tested for VOC adsorption and demonstrated to display affinity for acetonitrile and nitromethane, with high selectivity for the latter, but also to have the ability to trap aromatic VOCs, capturing up to ca. 2 mmol/g of solvent. The adsorption experiments, conducted at r.t., 1 atm, and no prior activation, underscore the potential of these materials for environmental and industrial applications. This work emphasizes the unique dynamic and selective behavior of bispidine-based CPs and provides a foundation for their scalability and practical implementation in VOCs capture technologies.