title: Chain-length-dependent vibrational resonances in alkanethiol self-assembled monolayers observed on plasmonic nanoparticle substrates.
abstract: Alkanethiol self-assembled monolayers (SAMs) on gold exhibit a series of sharp resonances in their surface-enhanced Raman spectrum that depend dramatically on carbon chain length. This unusual behavior suggests a coupling of the gold-sulfur bond stretch with the longitudinal acoustic, "accordion", vibrations of the molecular alkane chain. A simple model of a one-dimensional chain attached to a surface quantitatively reproduces these previously unreported experimental observations in this important nanomaterial system.
authors.affiliation: Department of Chemistry and the Laboratory for Nanophotonics, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
authors.forename: Carly S
authors.initials: CS
authors.lastname: Levin
authors.forename: Benjamin G
authors.initials: BG
authors.lastname: Janesko
authors.forename: Rizia
authors.initials: R
authors.lastname: Bardhan
authors.forename: Gustavo E
authors.initials: GE
authors.lastname: Scuseria
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Hartgerink
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Halas
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000379:methods; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties; D014732:Vibration
chemical_list: D000473:Alkanes; D013438:Sulfhydryl Compounds; D002244:Carbon; D006046:Gold