Pressure-Induced Self-Assembly in 3-Phenylpropanal: Distinct Clustering via π-Stacking and Distorted Hydrogen Bonds

This paper investigates the effect of high pressure on the dynamics, intermolecular interactions, and association mechanisms of 3-phenylpropanal (3P1 Pal). Dielectric investigations have revealed an unusual behavior of the Debye process at high compression, indicating a distinct clustering mechanism. Complementary Fourier Transform Infrared and Raman spectroscopy studies, supported by molecular dynamics simulations, have shown that, at high pressure, molecular clustering is dominated by π-stacking and strong, distorted hydrogen bonds, with larger and more compact aggregates, compared to those formed at low temperatures. Overall, high compression effectively tunes both dynamics and association patterns in 3P1 Pal, revealing key aspects of self-assembly in viscous molecular liquids.