Single-molecule level control of host-guest interactions in metallocycle-C60 complexes

Tang, Jian-Hong and Li, Yueqi and Wu, Qingqing and Wang, Zixiao and Hou, Songjun and Tang, Kun and Sun, Yue and Wang, Hui and Wang, Heng and Lu, Cheng and Wang, Xiang and Li, Xiaopeng and Wang, Dong and Yao, Jiannian and Lambert, Colin and Tao, Nongjian and Zhong, Yu-Wu and Stang, Peter J. (2019) Single-molecule level control of host-guest interactions in metallocycle-C60 complexes. Nature Communications, 10 (4599). ISSN 2041-1723

Text (s41467-019-12534-6)
s41467_019_12534_6.pdf - Published Version
Available under License Creative Commons Attribution.
Download (1MB)

Abstract

Host−guest interactions are of central importance in many biological and chemical processes. However, the investigation of the formation and decomplexation of host−guest systems at the single-molecule level has been a challenging task. Here we show that the single-molecule conductance of organoplatinum(II) metallocycle hosts can be enhanced by an order of magnitude by the incorporation of a C60 guest molecule. Mechanically stretching the metallocycle-C60 junction with a scanning tunneling microscopy break junction technique causes the release of the C60 guest from the metallocycle, and consequently the conductance switches back to the free-host level. Metallocycle hosts with different shapes and cavity sizes show different degrees of flexibility to accommodate the C60 guest in response to mechanical stretching. DFT calculations provide further insights into the electronic structures and charge transport properties of the molecular junctions based on metallocycles and the metallocycle-C60 complexes.