Supramolecular clusters and chains of 2,6-dimethylpyridine on Cu(110): Observation of dynamic configuration change with real-space surface science techniques and DFT calculations

SURFACE SCIENCE

卷:652

Article

Lee, Junseok^1,2,5  Sorescu, Dan C.^1,6  Lee, Jae-Gook^3,5  Dougherty, Dan^4,5 

[1] Natl Energy Technol Lab, Pittsburgh, PA 15236 USA

[2] AECOM, POB 618,South Pk, Los Angeles, CA USA

[3] LAM Res Corp, Etch Prod Grp, 4400 Cushing Pkwy, Fremont, CA 94539 USA

[4] N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA

[5] Univ Pittsburgh, Ctr Surface Sci, Dept Chem, Pittsburgh, PA 15261 USA

[6] Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 USA

关键词: Adatom;    Hydrogen bonding;    Nanostructure;    Self-assembly;    STM;    DFT;   

DOI  :  10.1016/j.susc.2016.01.020

来源: Elsevier

【 摘 要 】

The adsorption of 2,6-dimethylpyridine (2,6-DMP) on Cu(110) has been studied using low temperature scanning tunneling microscopy (LT-STM), time-of-flight electron stimulated desorption ion angular distribution (TOF-ESDIAD), and density functional theory (DFT) calculations. At low temperatures (T < similar to 150 K), the 2,6-DMP adsorbs in a flat configuration on Cu(110) producing clusters and extended domains via weak hydrogen bonding (C-H center dot center dot center dot N) with the molecular symmetry axis aligned along the < 001 > surface direction. At near-saturation coverage, a c(6 x 2) long-range ordered structure was observed. Upon annealing to T = 200 K, the 2,6-DMP molecules adopt an upright configuration with their pyridine ring plane oriented parallel to the <1 (1) over bar0> azimuth. These upright 2,6-DMP molecules produce extended molecular chains where the repulsive interactions between the molecular chains give rise to coverage-dependent interchain distances. At near-saturation coverage, a (12 60 surface structure is observed for the upright configuration. The DFT calculations suggest that the Cu adatom plays an important role in the adsorption configuration change of the 2,6-DMP molecule. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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