Semithio-bambusurils are a unique family of anion-binding host macrocycles that form self-assembled monolayers (SAMs) on Au(111). SAMs of semithio-bambus[n]uril homologs with different cage sizes (1: N = 4; 2: N = 6) have been investigated using electrochemistry, X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and molecular dynamics (MD) simulations. Electrochemical measurements showed that electron transfer occurs via tunneling through the SAMs, and the low resistivity indicated an open layer architecture. XPS confirmed that thiocarbonyl sulfur atoms are chemisorbed to the Au(111) surface, and STM revealed the formation of ordered domains in a rectangular lattice for 1 and a highly ordered triangular/hexagonal lattice for 2. MD simulations substantiated the STM data by quantifying the balance between molecule-surface bonding, molecular conformations, and supramolecular packing that drive the formation of SAMs that maximize their surface coverage within the limits of conformational strain.
|Number of pages||10|
|Journal||Molecular Systems Design and Engineering|
|State||Published - Feb 2020|
Bibliographical noteFunding Information:
Gerard Kip is acknowledged for XPS measurements. P. P. K. is grateful to the Karnataka state government for providing a scholarship under the D Devraj Urs Videshi Vyasanga Vetana scheme. D. T. acknowledges support by Science Foundation Ireland (SFI) under awards number 15/CDA/3491 and 12/RC/ 2275 (SSPC), and acknowledges computing resources at the SFI/Higher Education Authority Irish Center for High-End Computing (ICHEC). The Open University of Israel (OUI) is gratefully acknowledged for financial support (OR).
© 2020 The Royal Society of Chemistry.