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A 16 channel reflectance anisotropy (RA) spectrometer capable of simultaneously acquiring reflectance spectra and real and imaginary RA spectra on the 0.1 s time-scale is reported. Its performance was evaluated by monitoring the electrolytic deposition/growth and removal of copper on a gold(110) surface. The slow deposition enabled very low noise spectra to be obtained, which served as the yardstick with which the spectra obtained during the rapid removal could be compared. The spectra obtained over the 15 s removal mirrored those obtained during the 500 s deposition period. The spectra are discussed in terms of the copper growth being in the form of aligned islands.

The reflection anisotropy spectra of pyridine adsorbed onto a Au͑110͒ surface in an electrochemical cell demonstrates that this system forms an ordered structure. The reflection anisotropy spectroscopy ͑RAS͒ of pyridine/Au͑110͒ is attributed to n Ϫ * transitions which are shifted from their position in gas-phase spectra by the effects of the interaction of the N lone pair orbitals with the Au͑110͒ surface. The time dependence of the reflection anisotropy spectrum of the pyridine/Au͑110͒ system shows that after the initial onset of pyridine adsorption it takes ϳ5 min for the system to yield the spectrum of the equilibrium ordered structure. A similar time is required for the RAS signal to return to that of the Au͑110͒ surface following the desorption of pyridine.

The reflection anisotropy spectra of 2,2 -bipyridine and 4,4 -bipyridine adsorbed onto an Au(110) surface in an electrochemical cell demonstrate that both systems form ordered structures. It is shown that reflection anisotropy spectroscopy can be used to distinguish between structural isomers adsorbed on the Au(110) surface.

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