title: Higher-order complexity through R-group effects in self-assembled tripeptide monolayers.
abstract: Self-assembled monolayers of tri-L-leucine and tri-L-valine formed on highly ordered pyrolytic graphite (HOPG) substrates have been examined using scanning tunneling microscopy. These monolayers exhibit markedly different structures, even though the tripeptides differ by only a minor change in the amino acid R-group. This minor change in R-group apparently affects the balance between hydrogen bonding and van der Waals interactions that control the monolayer structures. Implications of this effect for evolution of molecular complexity in prebiotic synthesis on environmental surfaces are discussed.
authors.affiliation: Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Rampulla
authors.forename: Nuri
authors.initials: N
authors.lastname: Oncel
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Malcolm
authors.forename: Steven L
authors.initials: SL
authors.lastname: Bernasek
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D007930:Leucine / Q000138:chemical synthesis* / Q000737:chemistry; D008567:Membranes, Artificial; D016252:Microscopy, Scanning Tunneling; D008958:Models, Molecular; D008968:Molecular Conformation; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry; D010316:Particle Size; D013499:Surface Properties; D014633:Valine / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D008567:Membranes, Artificial; D009842:Oligopeptides; C009139:pyrolytic carbon; D002244:Carbon; D007930:Leucine; D014633:Valine