Enhancing single-molecule conductance of platinum (Ⅱ) complexes through synergistic aromaticity-assisted structural asymmetry  

作　　者：Ping Duan Junyang Liu Jin-Yun Wang Kai Qu Shuning Cai Fei Wang Lichuan Chen Xiaoyan Huang Ruihao Li Jia Shi Qian-Chong Zhang Wenjing Hong Zhong-Ning Chen 

机构地区：[1]State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,China [2]State Key Laboratory of Physical Chemistry of Solid Surfaces,Collaborative Innovation Center of Chemistry for Energy Materials(iChEM),NEL,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China

出　　处：《Science China Chemistry》2020年第4期467-474,共8页中国科学（化学英文版）

基　　金：the National Natural Science Foundation of China(21601182,U1405252,21531008,21673195,21703188,31871877,21933012);the National Key Research and Development Program of China(2014CB845603,2017YFA0204902);the CAS/SAFEA International Partnership Program for Creative Research Teams,the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000);China Postdoctoral Science Foundation(2017M622060).

摘　　要：Seeking the strategies of designing highly conductive molecular structures is one of the core researches in molecular electronics.As asymmetric structure has manifested feasible properties in comprehensive fields, we introduce the structures of asymmetric platinum(Ⅱ) complexes into the charge transport study at single-molecule scale for the first time. The single-molecule conductance measurement results reveal that, in platinum(Ⅱ)-aryloligoynyl structures, the conductance of asymmetrically coordinated complexes is obviously higher than that of the symmetric isomers with the same molecular length, while the conductance is almost identical in symmetric and asymmetric platinum(Ⅱ)-oligoynyl complexes. Theoretical study uncovers that, upon connecting to the oligoynyl structure, the aromatic group effectively extends the π-system of the whole conductive backbone and gathers the HOMO population mainly on the longer oligoynyl ligand, which reduces the energy barrier in electron transport and enhances the conductance through HOMO energy lifting. This result provides feasible strategy for achieving high conductive molecular devices.Seeking the strategies of designing highly conductive molecular structures is one of the core researches in molecular electronics.As asymmetric structure has manifested feasible properties in comprehensive fields, we introduce the structures of asymmetric platinum(Ⅱ) complexes into the charge transport study at single-molecule scale for the first time. The single-molecule conductance measurement results reveal that, in platinum(Ⅱ)-aryloligoynyl structures, the conductance of asymmetrically coordinated complexes is obviously higher than that of the symmetric isomers with the same molecular length, while the conductance is almost identical in symmetric and asymmetric platinum(Ⅱ)-oligoynyl complexes. Theoretical study uncovers that, upon connecting to the oligoynyl structure, the aromatic group effectively extends the π-system of the whole conductive backbone and gathers the HOMO population mainly on the longer oligoynyl ligand, which reduces the energy barrier in electron transport and enhances the conductance through HOMO energy lifting. This result provides feasible strategy for achieving high conductive molecular devices.

关 键 词：SINGLE-MOLECULE CONDUCTANCE ORGANOMETALLIC asymmetry CONDUCTANCE enhancement 

分 类 号：O641.4[理学—物理化学]