Quantifying the Bonding Strength of Gold-Chalcogen Bonds in Block Copolymer Systems

Wentian Xiang, Zhandong Li, Cong-Qiao Xu, Jun Li, Wenke Zhang, and Huaping Xu

Chem. Asian J. 201914, 1481–1486.

Gold–chalcogen interactions are ubiquitous in gold biological and medicinal systems. Understanding the nature of these interactions can provide the basis for regulating their structures and functionalities and a reasonable way to interpret the differences in various properties. However, the relative strength of gold–chalcogen bonds remains controversial, and the conclusions of many related works are inconsistent. Thus, in this work, we successfully quantified the relative strength of Au–X (X = S, Se, and Te from chalcogenide– containing A-B-A type block copolymer) interactions at the single-molecule level through single-molecule force spectroscopy (SMFS) from a kinetic point of view and quantum chemical studies from a thermodynamic point of view. Both sets of results suggested that the strength of the Au–X bonds decreases as Au–Te > Au–Se > Au–S. Our findings unveiled the relative strength and nature of gold– chalcogen interactions, which may help expand their application in electronics, catalysis, medicine and many other fields.