Structural Motif Selection in Fluorinated Metal-Organic Chalcogenides Driven by Ligand Electrostatics

TL;DR

This study reveals how ligand electrostatics influence structural motif selection in fluorinated metal-organic chalcogenides, providing a design principle for tuning crystal structures via ligand packing.

Contribution

It demonstrates that ligand-ligand electrostatic interactions are the key factor in determining structural motifs in MOCs, advancing mechanistic understanding.

Findings

Ligand electrostatics decisively influence motif selection.

Ligand orientation affects electrostatic stabilization.

A design principle for controlling MOC structures is established.

Abstract

Hybrid organic-inorganic materials enable systematic structural tuning through chemical modification of organic ligands. Predictive control, however, requires mechanistic understanding of how ligand chemistry and inorganic frameworks jointly determine structural motif selection. Metal-organic chalcogenides (MOCs), where metal-chalcogenide units are covalently bonded to organic ligands, offer an ideal platform in which ligand substitution directly alters crystal structure. Here, we investigate silver selenide-based MOCs with fluorinated phenyl ligands to elucidate governing interactions. Density functional theory with fragment-based energy analysis identifies ligand-ligand interactions as the primary energetic driver of motif selection. Symmetry-adapted perturbation theory further decomposes ligand-ligand interactions and shows that electrostatic interactions are decisive in selecting the preferred motif by selectively stabilizing specific packing arrangements. The results further show that ligand orientation controls the effectiveness of long-range electrostatic interactions, establishing a physically grounded design principle for directing structural motifs in MOCs through targeted control of ligand packing and electrostatics.