Theoretical structural study of van der Waals complexes between oxazole and atmospheric gases CO2 and N2 for capture applications.

Abstract

<ns3:p> Background The objective of this study is to explore the potential of oxazole (C <ns3:sub>3</ns3:sub> H <ns3:sub>3</ns3:sub> NO), a fascinating heterocyclic compound naturally present, which is a potential ligand in the construction of Metal-Organic Frameworks (MOFs) for the selective capture of CO <ns3:sub>2</ns3:sub> in a nitrogen-rich atmosphere, using both molecular and solid-state simulation techniques. Methods This study investigates the equilibrium structures and binding energies of van der Waals aggregates formed by an oxazole molecule with nonpolar molecules such as CO <ns3:sub>2</ns3:sub> and N <ns3:sub>2</ns3:sub> , considering both two-body systems (oxazole-CO <ns3:sub>2</ns3:sub> and oxazole-N <ns3:sub>2</ns3:sub> ) and three-body systems (oxazole-CO <ns3:sub>2</ns3:sub> -N <ns3:sub>2</ns3:sub> and oxazole-CO <ns3:sub>2</ns3:sub> /N <ns3:sub>2</ns3:sub> -Au <ns3:sub>6</ns3:sub> /Cu <ns3:sub>6</ns3:sub> /Zn <ns3:sub>3</ns3:sub> O <ns3:sub>3</ns3:sub> ). Molecular computations for these systems are conducted using ab initio calculations at the MP2/aug-cc-pVXZ level of theory, where X = (D, T). Additionally, solid-state simulations analyze the adsorption behaviors and energies of oxazole-CO <ns3:sub>2</ns3:sub> and oxazole-N <ns3:sub>2</ns3:sub> on metallic surfaces:Au, Cu and ZnO(111) through Monte Carlo methods. Results We find that the oxazole exhibits more adsorption selectivity for CO <ns3:sub>2</ns3:sub> than for N <ns3:sub>2</ns3:sub> . Adding a second gas to the most stable complexes, oxazole@CO <ns3:sub>2</ns3:sub> and oxazole@N <ns3:sub>2</ns3:sub> , the oxazole capture ability does not vary. On the contrary, it strengthens the adsorption energy of three-body complexes compared to two-body complexes. The addition of metallic clusters (Au <ns3:sub>6</ns3:sub> , Cu <ns3:sub>6</ns3:sub> , Zn <ns3:sub>3</ns3:sub> O <ns3:sub>3</ns3:sub> ) and metallic surfaces (Au, Cu, ZnO) enhances the adsorption capacity, where Cu <ns3:sub>6</ns3:sub> is particularly efficient. Both ZnO and Cu surfaces offer significant adsorption advantages while remaining economically feasible. Conclusions This study demonstrates that oxazole exhibits a strong selectivity for CO <ns3:sub>2</ns3:sub> over N <ns3:sub>2</ns3:sub> , with the addition of metallic clusters and surfaces significantly enhancing its adsorption capacity. These findings highlight the potential of oxazole-based materials for effective gas capture and separation, with positive implications for environmental sustainability. </ns3:p>