Single-molecule vibrational spectroscopy and microscopy

Vibrational spectra for a single molecule adsorbed on a solid surface have been obtained with a scanning tunneling microscope (STM). Inelastic electron tunneling spectra for an isolated acetylene (C2H2) molecule adsorbed on the copper (100) surface showed an increase in the tunneling conductance at 358 millivolts, resulting from excitation of the C-H stretch mode. An isotopic shift to 266 millivolts was observed for deuterated acetylene (C2D2). Vibrational microscopy from spatial imaging of the inelastic tunneling channels yielded additional data to further distinguish and characterize the two isotopes. Single-molecule vibrational analysis should lead to better understanding and control of surface chemistry at the atomic level.

[1]  B. Persson,et al.  Inelastic electron tunnelling from a metal tip , 1986 .

[2]  Douglas E. Smith,et al.  Molecular images and vibrational spectroscopy of sorbic acid with the scanning tunneling microscope , 1987 .

[3]  J. Lambe,et al.  Molecular Vibration Spectra by Electron Tunneling , 1966 .

[4]  P. Hansma,et al.  A measurement of the sensitivity of inelastic electron tunneling spectroscopy , 1977 .

[5]  Ray F. Egerton,et al.  Electron Energy-Loss Spectroscopy , 1997, Microscopy and Microanalysis.

[6]  Garcia,et al.  Conductivity sensitivity of inelastic scanning tunneling microscopy. , 1985, Physical review. B, Condensed matter.

[7]  Surface electronic structure of Si(111)-(7x7) resolved in real space. , 1986 .

[8]  B. Stipe,et al.  Atomistic studies of O2 dissociation on Pt(111) induced by photons, electrons, and by heating , 1997 .

[9]  J. Stöhr,et al.  Position of the σ-shape and π resonances of C2H2, C2H4 and C2H6 on Cu(100) at 60 K: A NEXAFS study , 1986 .

[10]  W. H. Weinberg.  Inelastic Electron Tunneling Spectroscopy: A Probe of the Vibrational Structure of Surface Species , 1978 .

[11]  M. Pemble,et al.  Low temperature electron energy loss spectra of acetylene chemisorbed on metal single-crystal surfaces; Cu(111), Ni(110) and Pd(110) , 1984 .

[12]  N. R. Avery.  Adsorption and Reactivity of Acetylene on a Cu(110) Surface. , 1985 .

[13]  Gregory.  Inelastic tunneling spectroscopy and single-electron tunneling in an adjustable microscopic tunnel junction. , 1990, Physical review letters.

[14]  B. Persson,et al.  Inelastic electron tunneling from a metal tip: The contribution from resonant processes. , 1987, Physical review letters.