Repulsion-Mediated Condensation of F ₁₆ CuPc on the Ag(100) Surface

This study explores the growth dynamics of fluorinated copper phthalocyanine (F16CuPc) on Ag(100) surfaces, focusing on the transition from a two-dimensional (2D) molecular gas phase to a condensed 2D phase at room temperature. Using a combination of real-space and reciprocal-space techniques, we reveal how repulsive intermolecular interactions, primarily driven by dipole–dipole forces, delay the condensation into an ordered structure. Low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM) provide insights into the structural evolution, while density functional theory (DFT) calculations elucidate the underlying mechanisms of molecular interactions. Our findings highlight the critical role of surface-mediated repulsion in stabilizing the 2D gas phase and its influence on the molecular arrangement during condensation. This work advances the understanding of F16CuPc adsorption up to the second layer and provides information about the interactions responsible for controlling the intermolecular arrangement.