Impact of structure on lattice vibrations in zirconium-based metal-organic frameworks

Raman spectroscopy was employed to systematically investigate how linker length, cluster type, metal identity, and framework topology influence the lattice vibrations of metal–organic frameworks (MOFs), using a series of Zr/Hf-based MOFs as model systems. The results reveal that shorter linkers induce more pronounced shifts in Raman bands, reflecting increased bond stiffness and heightened structural strain. Replacing Zr with Hf consistently led to higher-frequency Raman modes, while distinct differences emerged in the fingerprint region, underscoring the specific impact of the metal center. Additionally, the study highlights how variations in framework connectivity and the presence of defects significantly reshape the vibrational signatures, demonstrating that these structural factors play a crucial role in defining the vibrational landscape. Collectively, these insights advance the understanding of structure–property relationships in MOFs and support the rational design of materials with tailored mechanical and vibrational characteristics.