Construction of poly-naphthalocyanine linked by [4]-radialene-like structures on silver surfaces  

作　　者：Rongting Wu De-Liang Bao Linghao Yan Junhai Ren Yanfang Zhang Qi Zheng Ye-Liang Wang Qing Huan Shixuan Du Hong-Jun Gao 

机构地区：[1]Present address:Department of Applied Physics,Yale University,New Haven,06511,USA [2]Institute of Physics&University of Chinese Academy of Sciences,Chinese Academy of Sciences,Beijing,100190,China [3]CAS Center for Excellence in Topological Quantum Computation,Chinese Academy of Sciences,Beijing,100190,China [4]Songshan Lake Materials Laboratory,Dongguan,523808,China

出　　处：《Nano Research》2021年第12期4563-4568,共6页纳米研究（英文版）

基　　金：This work was financially supported by the National Key Research and Development Program of China(No.2016YFA0202300);the National Natural Science Foundation of China(Nos.61888102 and 61725107);Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB30000000);the International Partnership Program of Chinese Academy of Sciences(No.112111KYSB20160061);China Postdoctoral Science Foundation(No.2018M641511).

摘　　要：Cyclic-conjugated linkages between planar-macrocydic molecules contribute to the robustness of the two-dimensional (2D) polymerization and extension of π-interactions. The fabrication of such linkages in 2D polymers remains challenging. Combining scanning tunneling microscope (STM) measurements and density functional theory (DFT) calculations, we demonstrate a linear polymerization of metal-free naphthalocyanine (NPc) molecules with [4]-radialene-like linkages on silver surfaces. Experimentally, by depositing NPc molecules on the Ag(110) surface and subsequent annealing up to 750 K, one-dimensional polymers are constructed along the [\(1\overline 1 0\)] direction. High-resolution STM images show a stem-leaf-like feature. STM simulations based on a linear polymer of NPc molecules linked by four-membered carbon rings, [4]-radialene-like structure, agree well with the experimental observations. DFT calculations reveal that the polymerization process includes detaching two-terminal H atoms of NPc molecules along [\(1\overline 1 0\)] direction, then bonding with a neighboring dehydrogenated NPc molecule by forming a four-membered ring. The dehydrogenation process can be promoted by on-surface impurities such as additional H atoms. Similar polymerizations have been achieved on Ag(111) surfaces in an amorphous way. Moreover, the energy gap of the NPc molecule decreases after linear polymerization, suggesting a red-shift for its optical absorption/scattering spectrum. Our study offers a new route to polymerize conjugated molecules with extended planar π-interactions.

关 键 词：POLYMERIZATION NAPHTHALOCYANINE π-interaction extension scanning tunneling microscope density functional theory calculation 

分 类 号：O62[理学—有机化学]