| Abstract
| - Analyses of time-resolved sequences of molecular-resolution images allow the characterization andquantification of site-specific interactions and dynamics of adsorbed species. We have used scanning tunnelingmicroscopy to probe and to quantify the weak substrate-mediated interactions in benzene overlayers on Au{111}at 4 K. We observed that benzene molecules exhibit three types of motion; two-dimensional (2D) desorption,2D adsorption, and simultaneous cooperative shifts (2.4 ± 0.6 Å) of many molecules in molecular cascades.Correlating the probability of 2D desorption with the number of nearest neighbors of the desorbing moleculesenables the calculation of the magnitude of the adsorbate−adsorbate, substrate-mediated interactions. Weobserved molecular cascades in chains of up to 12 molecules simultaneously moving in the same direction.These molecular cascades arise from translation of the overlayer structure and are highly correlated with 2Ddesorption and 2D adsorption.
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