2020/06/30 by V. G. Artemov, В. Г. Артемов, Alexander Ryzhov +6 · 9 citations
Chemistry · Physics and Astronomy · #Advanced Chemical Physics Studies #Chemical physics #Chemical polarity #Chemistry #Computational chemistry #Debye #Dielectric #Intermolecular force #Materials science #Molecular Spectroscopy and Structure #Molecule #Optoelectronics #Organic chemistry #Physical chemistry #Physics #Polar #Polarization (electrochemistry) #Proton #Quantum #Quantum mechanics #Quantum tunnelling #Spectroscopy #Spectroscopy and Quantum Chemical Studies #Terahertz radiation #cond-mat.mtrl-sci #physics.chem-ph
paper · pdf · doi:10.1021/acs.jpcb.0c09380
published in The Journal of Physical Chemistry B 124(48), 11022-11029 (American Chemical Society)
openalex publication_date 2020/11/23 · arxiv created 2020/12/14 · arxiv updated 2020/12/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Chemical polarity governs various mechanical, chemical, and thermodynamic properties of dielectrics. Polar liquids have been amply studied, yet the basic mechanisms underpinning their dielectric properties remain not fully understood, as standard models following Debye's phenomenological approach do not account for quantum effects and cannot aptly reproduce the full dc-up-to-THz spectral range. Here, using the illustrative case of monohydric alcohols, we show that deep tunneling and the consequent intermolecular separation of excess protons and "proton-holes" in the polar liquids govern their static and dynamic dielectric properties on the same footing. We performed systematic ultrabroadband (0-10 THz) spectroscopy experiments with monohydric alcohols of different (0.4-1.6 nm) molecular lengths and show that the finite lifetime of molecular species and the proton-hole correlation length are the two principle parameters responsible for the dielectric response of all the studied alcohols across the entire frequency range. Our results demonstrate that a quantum nonrotational intermolecular mechanism drives the polarization in alcohols while the rotational mechanism of molecular polarization plays a secondary role, manifesting itself in the sub-terahertz region only.