Corresponding Author

Yuan GUO(guoyuan@iccas.ac.cn)


The electrochemical interface between liquid acetonitrile and polycrystal gold electrode is investigated by in situ infrared visible sum frequency generation spectroscopy (SFG-VS). The structure of acetonitrile adsorbed at polycrystal gold electrode surface is studied as a function of electrode potential. The SFG spectra of CH3 group indicate acetonitrile orients in response to the electrode potential. The SFG signal of CH3 group turns lower as the electrode potential changes from -700mV to 300mV, and vanishes around the 300mV(pzc), then becomes a negative signal above 500mV, which indicates that the orientation is predominately with the CH3 group toward the metal between -700 and 300mV and with the CN group toward the metal above 300 mV. It is the first time to observe the flip-flop behavior of acetonitrile dipole at the polycrystal gold electrode surface, from which we may infer that the flip-flop behavior of acetonitrile is a common phenomenon.

Graphical Abstract


sum frequency generation vibrational spectroscopy, flip-flop, gold electrode, acetonitrile

Publication Date


Online Available Date


Revised Date


Received Date



[1]Bockris J O M, Reddy A K N. Modern electrochemistry 2A[M]. New York, Boston: Kluwer Academic Publishers, 2002.

[2]Renato C A, Gewirth A A. Characterization of water structure on silver electrode surfaces by SERS with two-dimensional correlation spectroscopy[J]. Anal Chem, 2010, 82(4): 1305€“1310.

[3]Yao Jian-Lin, Yuan Ya-Xian, Fan Xiao-Min, et al. The reorientation of benzonitrile on platinum electrode probed by surface enhanced Raman spectroscopy[J]. J Electroanal Chem, 2008, 624(1/2): 129€“133.

[4]Rudneva A V, Molodkinaa E B, Danilova A I, et al. Adsorption behavior of acetonitrile on platinum and gold electrodes of various structures in solution of 0.5M H2SO4[J]. Electrochimica Acta, 2009, 54: 3692€“3699.

[5]Ataka K,Osawa M. In situ infrared study of water-sulfate coadsorption on gold(111) in sulfuric acid solutions[J]. Langmuir, 1998, 14(4): 951-959.

[6]Toney M F, Howard J N, Richer J, et al. Voltage-dependent ordering of water molecules at an electrode€“electrolyte interface[J]. Nature, 1994, 368: 444-446.

[7]Lucas C A, Thompson P, Cormack M, et al. Temperature-induced ordering of metal/adsorbate structures at electrochemical interfaces[J]. J Am Chem Soc, 2009, 131: 7654€“7661.

[8]Duan Sai, Wu De-Yin, Xu Xin, et al. Structures of water molecules adsorbed on a gold electrode under negative potentials[J]. J Phys Chem C, 2010, 114 (9): 4051€“4056.

[9]Markovits A, Minot C. Theoretical study of the acetonitrile flip-flop with the electric field orientation: adsorption on a Pt(111) electrode surface[J]. Catalysis Letters, 2003, 91(3/4):225-234.

[10]Raschke M B,Shen Y R. Nonlinear optical spectroscopy of solid interfaces[J]. Current Opinion in Solid State and Materials Science, 2004, 8: 343€“352.

[11]Hopkins A J, McFearin C L,Richmond G L. Investigations of the solid-aqueous interface with vibrational sum-frequency spectroscopy[J]. Current Opinion in Solid State and Materials Science, 2005, 9: 19€“27.

[12]Somorjai G A ,Park J Y. Concepts, instruments, and model systems that enabled the rapid evolution of surface science[J]. Sur Sci, 2009, 603: 1293€“1300.

[13]Vidal F,Tadjeddine A. Sum-frequency generation spectroscopy of interfaces[J]. Rep Prog Phys, 2005, 68: 1095€“1127.

[14]Noguchi H, Okada T, Uosaki K. SFG study on potential-dependent structure of water at Pt electrode/electrolyte solution interface[J]. Electrochimica Acta, 2008, 53: 6841€“6844.

[15]Nihonyanagi S, Ye S, Uosaki K,et al. Potential-dependent structure of the interfacial water on the gold electrode[J]. Sur Sci, 2004, 573: 11€“16.

[16]Schultz Z D, Shaw S K,Gewirth A A. Potential dependent organization of water at the electrified metal-liquid interface[J]. J Am Chem Soc, 2005, 127: 15916-15922.

[17]Zheng W Q,Tadjeddine A. Adsorption processes and structure of water molecules on Pt(110) electrodes in perchloric solutions[J]. J Chem Phys, 2003, 119 (24): 13096-13099.

[18]Peremans A,Tadjeddine A. Electrochemical deposition of hydrogen on platinum single crystals studied by infrared-visible sum-frequency generation[J]. J Chem Phys, 1995, 103 (16): 7197-7203.

[19]Tadjeddine A,Peremans A. Vibrational spectroscopy of the electrochemical interface by visible infrared sum frequency generation[J]. J Electroanal Chem, 1996, 409: 115-121.

[20]Noguchi H, Okada T, Uosaki K. Molecular structure at electrode/electrolyte solution interfaces related to electrocatalysis[J]. Faraday Discuss, 2008, 140: 125€“137.

[21]Baldelli S, Mailhot G, Ross P N, et al. Potential-dependent vibrational spectroscopy of solvent molecules at the Pt(111) electrode in a water/acetonitrile mixture studied by sum frequency generation[J]. J Am Chem Soc, 2001, 123: 7697-7702.

[22]Baldelli S, Mailhot G, Ross P, et al. Potential dependent orientation of acetonitrile on platinum (111) electrode surface studied by sum frequency generation[J]. J Phys Chem B, 2001, 105: 654-662.

[23]Roke S, Kleyn A W, Bonn M, Femtosecond sum frequency generation at the metal€“liquid interface[J]. Sur Sci, 2005, 593: 79€“88.

[24]Casillas-Ituarte N N,Allen H C. Interfacial organization of acetonitrile: simulation and experiment[J]. Chem Phy Lett, 2009, 483: 84€“89.

[25]Faguy P W, Fawcett W R, Liu G,et al. A study of the adsorption of acetonitrile on a gold electrode from aqueous solutions using in situ vibrational spectroscopy[J]. J Electroanal Chem, 1992, 339: 339-353.

[26]Waldrup S B, Williams C T. Acetonitrile adsorption on polycrystalline platinum: an in situ investigation using sum frequency spectroscopy[J]. J Phys Chem C, 2008, 112: 219-226.

[27]Ding F, Hu Z H, Zhong Q, et al. Interfacial organization of acetonitrile: simulation and experiment[J]. J Phys Chem C, 2010, 114(41): 17651-17659.

[28]Wang Hong-fei, Gan Wei, Lu Rong, et al.Quantitative spectral and orientational analysis in surface sum frequency generation vibrational spectroscopy (SFG-VS)[J]. Int Rev Phy Chem, 2005, 24: 191-256.

[29]Miranda P B,Shen Y R. Liquid interfaces: A study by sum-frequency vibrational spectroscopy[J]. J Phys Chem B, 1999, 103(17): 3292-3307.

[30]Zhuang X, Miranda P B, Kim D,et al. Mapping molecular orientation and conformation at interfaces by surface nonlinear optics[J]. Phys Rev B, 1999, 59(19): 12632-12640.

[31]Zheng De-Sheng, Wang Yuan, Liu An-An, et al. Microscopic molecular optics theory of surface second harmonic generation and sum-frequency generation spectroscopy based on the discrete dipole lattice model[J]. Int Rev Phy Chem, 2008, 27(4): 629€“664.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.