We report the molecular dynamics studies on the interfacial behavior of cesium (Cs⁺) extraction by bis(2-propyloxy)calix [4]crown-6 (BPC6) and dicyclohexano-18-crown-6 (DCH18C6). For the benchmarking study, the phase separation for [BMIM][Tf₂N]-water was validated. Thereafter, to understand the mechanism of complexation and the behavior of the crown ether ligand, crown ether (CE) molecules and Cs⁺NO₃⁻ ions were inserted randomly in the ionic liquid (IL)–water biphasic system. It was observed that the 2:1 Cs⁺-BPC6 complex formed during the simulationwasmore stable at the interface andwas found to diffuse slowly to the IL side of the interface. On the contrary the 1:1 Cs⁺-DCH18C6 complex was found to be fully solvated in the bulk IL phase. The [BMIM]+cationwas found to partition to the aqueous phase and exchangewith Cs+ion in presence or absence of CE. The solubility, density plots and the snapshots of the [BMIM]⁺ cation at the IL–water interface indicates the dual cationic exchange. A comparison of the interfacial behavior of Cs⁺-BPC6 complex and Cs⁺-DCH18C6 complex in IL–water preformed interface system, depicted that the Cs+-BPC6 complex was stable at the interface till the end of the simulation. One the other hand, the uncomplexed DCH18C6 resided at the interface,while the Cs⁺ ion diffused to the bulk aqueous phase. The calculated interaction energy of Cs⁺-BPC6 was found to higher as compared to Cs⁺-DCH18C6. These results display the importance of the dual cationic exchange properties of IL and the extraction efficiency of CE for extraction of metal ions.