Photooxidation of the Phenolate Anion is Accelerated at the Water/Air Interface

Molecular photodynamics can be dramatically affected at the water/air interface. Probing such dynamics is challenging, with product formation often probed indirectly through its interaction with interfacial water molecules using time-resolved and phase-sensitive vibrational sum-frequency generation (SFG). Here, the photoproduct formation of the phenolate anion at the water/air interface is probed directly using time-resolved electronic SFG and compared to transient absorption spectra in bulk water. The mechanisms are broadly similar, but 2 to 4 times faster at the surface. An additional decay is observed at the surface which can be assigned to either diffusion of hydrated electrons from the surface into the bulk or due to increased geminate recombination at the surface. These overall results are in stark contrast to phenol, where dynamics were observed to be 104 times faster and for which the hydrated electron was also a photoproduct. Our attempt to probe phenol showed no electron signal at the interface.

[1]  T. Tahara,et al.  Why the Photochemical Reaction of Phenol Becomes Ultrafast at the Air–Water Interface: The Effect of Surface Hydration , 2022, Journal of the American Chemical Society.

[2]  J. Verlet,et al.  Time-resolved electronic sum-frequency generation spectroscopy with fluorescence suppression using optical Kerr gating. , 2021, The Journal of chemical physics.

[3]  A. Allouche,et al.  Controlled ultrafast ππ*-πσ* dynamics in tryptophan-based peptides with tailored micro-environment , 2021, Communications Chemistry.

[4]  M. Fujii,et al.  Revealing the role of excited state proton transfer (ESPT) in excited state hydrogen transfer (ESHT): systematic study in phenol–(NH3)n clusters , 2021, Chemical science.

[5]  S. Nihonyanagi,et al.  The photochemical reaction of phenol becomes ultrafast at the air–water interface , 2021, Nature Chemistry.

[6]  J. S. Francisco,et al.  Photoinduced oxidation reactions at the air-water interface. , 2020, Journal of the American Chemical Society.

[7]  J. S. Francisco,et al.  Molecular reactions at aqueous interfaces , 2020, Nature Reviews Chemistry.

[8]  J. Verlet,et al.  On the Mechanism of Phenolate Photo-Oxidation in Aqueous Solution. , 2019, The journal of physical chemistry. B.

[9]  David A. Woods,et al.  Charge Transfer to Solvent Dynamics at the Ambient Water/Air Interface. , 2016, The journal of physical chemistry letters.

[10]  D. Donaldson,et al.  Atmospheric photochemistry at a fatty acid–coated air-water interface , 2016, Science.

[11]  S. Bradforth,et al.  Exploring Autoionization and Photoinduced Proton-Coupled Electron Transfer Pathways of Phenol in Aqueous Solution. , 2015, The journal of physical chemistry letters.

[12]  S. Yamaguchi,et al.  Development of Electronic Sum Frequency Generation Spectroscopies and Their Application to Liquid Interfaces , 2015 .

[13]  Christian George,et al.  Heterogeneous Photochemistry in the Atmosphere , 2015, Chemical reviews.

[14]  F. Uhlig,et al.  Direct observation of the collapse of the delocalized excess electron in water. , 2014, Nature chemistry.

[15]  S. Bradforth,et al.  Contrasting the excited state reaction pathways of phenol and para-methylthiophenol in the gas and liquid phases. , 2012, Faraday discussions.

[16]  P. Rossky,et al.  Theoretical studies of spectroscopy and dynamics of hydrated electrons. , 2012, Chemical reviews.

[17]  V. Stavros,et al.  Direct Observation of Hydrogen Tunneling Dynamics in Photoexcited Phenol. , 2012, The journal of physical chemistry letters.

[18]  M. Ashfold,et al.  Tunnelling under a conical intersection: application to the product vibrational state distributions in the UV photodissociation of phenols. , 2011, The Journal of chemical physics.

[19]  I. V. van Stokkum,et al.  Broadband spectral probing revealing ultrafast photochemical branching after ultraviolet excitation of the aqueous phenolate anion. , 2011, The journal of physical chemistry. A.

[20]  J. Herbert,et al.  Polarization-bound quasi-continuum states are responsible for the "blue tail" in the optical absorption spectrum of the aqueous electron. , 2010, Journal of the American Chemical Society.

[21]  C. Bain,et al.  Hydrated electrons at the water/air interface. , 2010, Journal of the American Chemical Society.

[22]  P. Rossky,et al.  Excess electron relaxation dynamics at water/air interfaces. , 2007, The Journal of chemical physics.

[23]  M. Cascella,et al.  Microsolvation effects on the excited-state dynamics of protonated tryptophan. , 2006, Journal of the American Chemical Society.

[24]  Jan B. F. N. Engberts,et al.  Organic chemistry: Fast reactions ‘on water’ , 2005, Nature.

[25]  M. Finn,et al.  "On water": unique reactivity of organic compounds in aqueous suspension. , 2005, Angewandte Chemie.

[26]  Chia-Chung Sun,et al.  The static polarizability and first hyperpolarizability of the water trimer anion: ab initio study. , 2004, The Journal of chemical physics.

[27]  Y. Lee,et al.  H atom elimination from the πσ* state in the photodissociation of phenol , 2004 .

[28]  Douglas J. Tobias,et al.  Ions at the Air/Water Interface , 2002 .

[29]  Gil,et al.  Electronic states of the phenoxyl radical , 2001 .

[30]  W. Domcke,et al.  Photoinduced Electron and Proton Transfer in Phenol and Its Clusters with Water and Ammonia , 2001 .

[31]  G. Granucci,et al.  A Theoretical Investigation of Excited-State Acidity of Phenol and Cyanophenols , 2000 .

[32]  Stephen E. Bradforth,et al.  The ejection distribution of solvated electrons generated by the one-photon photodetachment of aqueous I− and two-photon ionization of the solvent , 2000 .

[33]  K. Eisenthal,et al.  Liquid Interfaces Probed by Second-Harmonic and Sum-Frequency Spectroscopy. , 1996, Chemical reviews.

[34]  A. Staib,et al.  REACTION PATHWAYS IN THE PHOTODETACHMENT OF AN ELECTRON FROM AQUEOUS CHLORIDE : A QUANTUM MOLECULAR DYNAMICS STUDY , 1996 .

[35]  Yaochun Shen,et al.  Optical Second Harmonic Generation at Interfaces , 1989 .

[36]  K. Eisenthal,et al.  Picosecond dynamics of a chemical reaction at the air-water interface studied by surface second harmonic generation , 1988 .

[37]  G. Richmond,et al.  Second harmonic generation studies of interfacial structure and dynamics , 1988 .

[38]  F. Jou,et al.  Temperature and isotope effects on the shape of the optical absorption spectrum of solvated electrons in water , 1979 .