Real-Space Identification of Intermolecular Bonding with Atomic Force Microscopy

ROM 2013-12
Author: Xiaohui Qiu,
Institute: (1) National Center for Nanoscience and Technology, Beijing 100190, China (2) Department of Physics, Renmin University of China, Beijing 100872, China
Publication: Science DOI:10.1126/science.1242603
Instrument: LT STM

We report a real-space visualization of the formation of hydrogen bonding in 8-hydroxyquiline (8-hq) molecular assemblies on a Cu(111) substrate using noncontact atomic force microscopy (NC-AFM). The atomically resolved molecular structures enable a precise determination of the characteristics of hydrogen bonding networks, including the bonding sites, orientations, and lengths. The observation of bond contrast was interpreted by ab initio density functional calculations, which indicated the electron density contribution from the hybridized electronic state of the hydrogen bond. Intermolecular coordination between the dehydrogenated 8-hq and Cu adatoms was also revealed by the submolecular resolution AFM characterization. The direct identification of local bonding configurations by NC-AFM would facilitate detailed investigations of intermolecular interactions in complex molecules with multiple active sites.

Jun Zhang 1,+, Pengcheng Chen 1,+, Bingkai Yuan 1, Wei Ji 2,*, Zhihai Cheng 1,*, Xiaohui Qiu 1,*