Nanoscale Chemical Imaging of a Dynamic Molecular Phase Boundary with Ultrahigh Vacuum Tip-Enhanced Raman Spectroscopy

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• 作者：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
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：June 8, 2016
• 年：2016
• 卷：16
• 期：6
• 页码：3898-3904
• 全文大小：463K
• 年卷期：0
• ISSN：1530-6992

文摘

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.