김윤진 (포항공과대학교)

서종철 (포항공과대학교)

김윤진 (포항공과대학교)

서종철 (포항공과대학교)

Molecules and ions in the gas phase can assemble through electrostatic and noncovalent interactions to form ion clusters, providing simple model systems to understand molecular behavior distinct from that in bulk solution. In this study, we focused on alkali metal halide clusters containing [M–X–M]+ triple ions stabilized by two crown ethers acting as cyclic O-donor ligands. Their structures and binding properties were investigated using ion mobility spectrometry–mass spectrometry (IMS–MS) and collision-induced dissociation (CID). We found that the size complementarity between the crown ether cavity and the metal ion strongly influenced both the stability and conformational preferences of the (CE)2∙MXM+ clusters. To interpret the observed CID patterns, several candidate conformers were proposed, and their relative stabilities are currently being evaluated using density functional theory (DFT) calculations. We also examined the effects of electrospray ionization (ESI) source conditions and the CE-to-MX concentration ratio on cluster formation and conformer distributions. Our findings provide insight into how cyclic O-donor ligands govern the formation and stabilization of gas-phase ion clusters through size-selective metal coordination.