Bulklike Vibrational Coupling of Surface Water Revealed by Sum-Frequency Generation Spectroscopy
Kuo-Yang Chiang, Xiaoqing Yu, Chun‐Chieh Yu, Takakazu Seki, Shumei Sun, Mischa Bonn, Yuki Nagata
Abstract
Vibrational coupling between interfacial water molecules is important for energy dissipation after on-water chemistry, yet intensely debated. Here, we quantify the interfacial vibrational coupling strength through the linewidth of surface-specific vibrational spectra of the water's O─H (O─D) stretch region for neat H_{2}O/D_{2}O and their isotopic mixtures. The local-field-effect-corrected experimental SFG spectra reveal that the vibrational coupling between hydrogen-bonded interfacial water O─H groups is comparable to that in bulk water, despite the effective density reduction at the interface.
Topics & Concepts
Rotational–vibrational couplingLaser linewidthMaterials scienceCoupling (piping)Spectral lineInfrared spectroscopySpectroscopyMolecular vibrationMoleculeMolecular physicsHeavy waterHydrogenAtomic physicsChemical physicsDeuteriumChemistryPhysicsOpticsLaserMetallurgyAstronomyOrganic chemistryQuantum mechanicsSpectroscopy and Quantum Chemical StudiesQuantum, superfluid, helium dynamicsSpectroscopy and Laser Applications