Atomic scale imaging of alkanethiolate monolayers at gold surfaces with atomic force microscopy

Monolayer films formed by the chemisorption of alkanethiols (CH 3 (CH 2 ) n SH, n=1-17) at epitaxially grown Au(111) films were examined using atomic force microscopy (AFM). Atomically resolved images were found for films with n≥4, directly revealing for the first time the arrangement of the alkyl chain structure. All of the images exhibit a periodic hexagonal pattern of equivalent spacings (e.g., respective nearest- and next-nearest-neighbor distances of 0.52±0.03 and 0.90±0.04nm for n=17 and 0.51±0.02 and 0.92±0.06 nm for n=5)