Nature of Excess Hydrated Proton at the Water-Air Interface

Overview

Journal J Am Chem Soc

Publisher American Chemical Society

Specialty Chemistry

Date 2019 Dec 24

PMID 31867949

Citations 13

Authors

Sudipta Das

Sho Imoto

Shumei Sun

Yuki Nagata

Ellen H G Backus

Mischa Bonn

Affiliations

Soon will be listed here.

Abstract

Understanding the interfacial molecular structure of acidic aqueous solutions is important in the context of, e.g., atmospheric chemistry, biophysics, and electrochemistry. The hydration of the interfacial proton is necessarily different from that in the bulk, given the lower effective density of water at the interface, but has not yet been elucidated. Here, using surface-specific vibrational spectroscopy, we probe the response of interfacial protons at the water-air interface and reveal the interfacial proton continuum. Combined with spectral calculations based on ab initio molecular dynamics simulations, the proton at the water-air interface is shown to be well-hydrated, despite the limited availability of hydration water, with both Eigen and Zundel structures coexisting at the interface. Notwithstanding the interfacial hydrated proton exhibiting bulk-like structures, a substantial interfacial stabilization by -1.3 ± 0.2 kcal/mol is observed experimentally, in good agreement with our free energy calculations. The surface propensity of the proton can be attributed to the interaction between the hydrated proton and its counterion.

Citing Articles

Design of asymmetric electrolytes for aqueous zinc batteries.

Chen S, Zhi C Commun Chem. 2025; 8(1):20.

PMID: 39856186 PMC: 11759685. DOI: 10.1038/s42004-024-01405-x.

How Thick is the Air-Water Interface?─A Direct Experimental Measurement of the Decay Length of the Interfacial Structural Anisotropy.

Fellows A, Duque A, Balos V, Lehmann L, Netz R, Wolf M Langmuir. 2024; 40(35):18760-18772.

PMID: 39171356 PMC: 11375779. DOI: 10.1021/acs.langmuir.4c02571.

Double-Layer Distribution of Hydronium and Hydroxide Ions in the Air-Water Interface.

Zhang P, Feng M, Xu X ACS Phys Chem Au. 2024; 4(4):336-346.

PMID: 39069983 PMC: 11274287. DOI: 10.1021/acsphyschemau.3c00076.

Molecular Dynamics Simulation of Complex Reactivity with the Rapid Approach for Proton Transport and Other Reactions (RAPTOR) Software Package.

Kaiser S, Yue Z, Peng Y, Nguyen T, Chen S, Teng D J Phys Chem B. 2024; 128(20):4959-4974.

PMID: 38742764 PMC: 11129700. DOI: 10.1021/acs.jpcb.4c01987.

The role of charge in microdroplet redox chemistry.

Heindel J, LaCour R, Head-Gordon T Nat Commun. 2024; 15(1):3670.

PMID: 38693110 PMC: 11519639. DOI: 10.1038/s41467-024-47879-0.

References

Napoli J, Marsalek O, Markland T . Decoding the spectroscopic features and time scales of aqueous proton defects. J Chem Phys. 2018; 148(22):222833. DOI: 10.1063/1.5023704. View

Dreier L, Wolde-Kidan A, Bonthuis D, Netz R, Backus E, Bonn M . Unraveling the Origin of the Apparent Charge of Zwitterionic Lipid Layers. J Phys Chem Lett. 2019; 10(20):6355-6359. DOI: 10.1021/acs.jpclett.9b02587. View

Petersen P, Saykally R . Evidence for an enhanced hydronium concentration at the liquid water surface. J Phys Chem B. 2006; 109(16):7976-80. DOI: 10.1021/jp044479j. View

Thamer M, De Marco L, Ramasesha K, Mandal A, Tokmakoff A . Ultrafast 2D IR spectroscopy of the excess proton in liquid water. Science. 2015; 350(6256):78-82. DOI: 10.1126/science.aab3908. View

Lee H, Tuckerman M . Ab initio molecular dynamics studies of the liquid-vapor interface of an HCl solution. J Phys Chem A. 2009; 113(10):2144-51. DOI: 10.1021/jp809236c. View

Sun S, Tang F, Imoto S, Moberg D, Ohto T, Paesani F . Orientational Distribution of Free O-H Groups of Interfacial Water is Exponential. Phys Rev Lett. 2019; 121(24):246101. DOI: 10.1103/PhysRevLett.121.246101. View

Yu Q, Carpenter W, Lewis N, Tokmakoff A, Bowman J . High-Level VSCF/VCI Calculations Decode the Vibrational Spectrum of the Aqueous Proton. J Phys Chem B. 2019; 123(33):7214-7224. DOI: 10.1021/acs.jpcb.9b05723. View

Wen Y, Zha S, Liu X, Yang S, Guo P, Shi G . Unveiling Microscopic Structures of Charged Water Interfaces by Surface-Specific Vibrational Spectroscopy. Phys Rev Lett. 2016; 116(1):016101. DOI: 10.1103/PhysRevLett.116.016101. View

Baer M, Fulton J, Balasubramanian M, Schenter G, Mundy C . Persistent ion pairing in aqueous hydrochloric acid. J Phys Chem B. 2014; 118(26):7211-20. DOI: 10.1021/jp501091h. View

10.

Daly Jr C, Streacker L, Sun Y, Pattenaude S, Hassanali A, Petersen P . Decomposition of the Experimental Raman and Infrared Spectra of Acidic Water into Proton, Special Pair, and Counterion Contributions. J Phys Chem Lett. 2017; 8(21):5246-5252. DOI: 10.1021/acs.jpclett.7b02435. View

11.

Wei X, Shen Y . Motional effect in surface sum-frequency vibrational spectroscopy. Phys Rev Lett. 2001; 86(21):4799-802. DOI: 10.1103/PhysRevLett.86.4799. View

12.

Iuchi S, Chen H, Paesani F, Voth G . Hydrated excess proton at water-hydrophobic interfaces. J Phys Chem B. 2008; 113(13):4017-30. DOI: 10.1021/jp805304j. View

13.

Nagata Y, Hsieh C, Hasegawa T, Voll J, Backus E, Bonn M . Water Bending Mode at the Water-Vapor Interface Probed by Sum-Frequency Generation Spectroscopy: A Combined Molecular Dynamics Simulation and Experimental Study. J Phys Chem Lett. 2015; 4(11):1872-7. DOI: 10.1021/jz400683v. View

14.

Baer M, Kuo I, Tobias D, Mundy C . Toward a unified picture of the water self-ions at the air-water interface: a density functional theory perspective. J Phys Chem B. 2014; 118(28):8364-72. DOI: 10.1021/jp501854h. View

15.

Angelova M, Bitbol A, Seigneuret M, Staneva G, Kodama A, Sakuma Y . pH sensing by lipids in membranes: The fundamentals of pH-driven migration, polarization and deformations of lipid bilayer assemblies. Biochim Biophys Acta Biomembr. 2018; 1860(10):2042-2063. DOI: 10.1016/j.bbamem.2018.02.026. View

16.

Sengupta S, Moberg D, Paesani F, Tyrode E . Neat Water-Vapor Interface: Proton Continuum and the Nonresonant Background. J Phys Chem Lett. 2018; 9(23):6744-6749. DOI: 10.1021/acs.jpclett.8b03069. View

17.

Dahms F, Fingerhut B, Nibbering E, Pines E, Elsaesser T . Large-amplitude transfer motion of hydrated excess protons mapped by ultrafast 2D IR spectroscopy. Science. 2017; 357(6350):491-495. DOI: 10.1126/science.aan5144. View

18.

Tang F, Ohto T, Hasegawa T, Xie W, Xu L, Bonn M . Definition of Free O-H Groups of Water at the Air-Water Interface. J Chem Theory Comput. 2017; 14(1):357-364. DOI: 10.1021/acs.jctc.7b00566. View

19.

Tyrode E, Sengupta S, Sthoer A . Identifying Eigen-like hydrated protons at negatively charged interfaces. Nat Commun. 2020; 11(1):493. PMC: 6981112. DOI: 10.1038/s41467-020-14370-5. View

20.

Schaefer J, Backus E, Nagata Y, Bonn M . Both Inter- and Intramolecular Coupling of O-H Groups Determine the Vibrational Response of the Water/Air Interface. J Phys Chem Lett. 2016; 7(22):4591-4595. DOI: 10.1021/acs.jpclett.6b02513. View