Rectangular Nanostructuring of Au(111) Surfaces by Self-Assembly of Size-Selected Thiacrown Ether Macrocycles

Surface modification by self-assembled monolayers (SAMs) has continuously attracted considerable attention because of several potential applications in domains such as nanopatterning, biosensors and chemical sensors, and microelectronics.1,2 Organo-sulfur deriva-tives such as n-alkanethiols R-SH and dialkyl disulfides R-S-S-R ′ are the most extensively studied SAMs adsorbed on various metal surfaces such as gold, silver, or copper.3,4 In comparison, very few studies have been reported on SAMs based on thioethers R-S-R′. However, in an early report Troughton et al. studied the spontaneous self-assembly of symmetrical and unsymmetrical dialkyl sulfides onto gold substrates.5 More recently, Noh et al. investigated the adsorption of dioctadecyl sulfide SAMs on Au-(111) by scanning tunneling microscopy (STM) and high-resolution electron energy loss spectroscopy.6 It has been observed in particular that the C-S-C motif of dioctadecyl sulfide remains intact afte