Nanoscale chemical imaging of a dynamic molecular phase boundary with ultrahigh vacuum tip-enhanced raman spectroscopy

Nan Jiang, Naihao Chiang, Lindsey R. Madison, Eric A. Pozzi, Michael R Wasielewski, Tamar Seideman, Mark A Ratner, Mark C Hersam, George C Schatz, Richard P. Van Duyne

Research output: Contribution to journalArticle

49 Citations (Scopus)


Nanoscale chemical imaging of a dynamic molecular phase boundary has broad implications for a range of problems in catalysis, surface science, and molecular electronics. While scanning probe microscopy (SPM) is commonly used to study molecular phase boundaries, its information content can be severely compromised by surface diffusion, irregular packing, or three-dimensional adsorbate geometry. Here, we demonstrate the simultaneous chemical and structural analysis of N-N′-bis(2,6-diisopropylphenyl)-1,7-(4′-t-butylphenoxy)perylene-3,4:9,10-bis(dicarboximide) (PPDI) molecules by UHV tip-enhanced Raman spectroscopy. Both condensed and diffusing domains of PPDI coexist on Ag(100) at room temperature. Through comparison with time-dependent density functional theory simulations, we unravel the orientation of PPDI molecules at the dynamic molecular domain boundary with unprecedented ∼4 nm spatial resolution.

Original languageEnglish
Pages (from-to)3898-3904
Number of pages7
JournalNano Letters
Issue number6
Publication statusPublished - Jun 8 2016



  • dynamic molecular phase boundary
  • time-dependent density functional theory (TDDFT)
  • Tip-enhanced Raman spectroscopy (TERS)
  • ultrahigh vacuum scanning tunneling microscopy (UHV-STM)

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanical Engineering

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