| Abstract
| - We report the results of an in situ, vibrationally resonant sum frequency generation (SFG) spectroscopystudy of the assembly of perdeuterated dioctadecyl disulfide on gold substrates from ethanol solutionsunder laminar flow conditions. The coverage evolution of the SFG spectra can be well described by thecoexistence of two distinct phases: a low-coverage, disordered phase and the full-coverage crystallinephase. The structure of the adsorbed thiolate fragments in the low-coverage phase is disordered but upright(as opposed to lying completely in the surface plane), characterized by significant gauche defects in thebackbone but a near-normal orientation for the terminal methyl group. The crystalline phase is markedby an erect all-trans configuration of the alkane chain. The kinetics of the evolution of these two phasescan be quantitatively described by a simple model, consistent with phase coexistence above a criticaldensity of the disordered phase.
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