Flexible Vertex Engineers the Controlled Assembly of Distorted Supramolecular Tetrahedral and Octahedral Cages
Shu-Jin Bao,
Ze-Ming Xu,
Tian-Chen Yu,
Ying-Lin Song,
Heng Wang,
Zheng Niu,
Xiaopeng Li,
Brendan F. Abrahams,
Pierre Braunstein,
Jian-Ping Lang
Affiliations
Shu-Jin Bao
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China; State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
Ze-Ming Xu
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
Tian-Chen Yu
School of Physical Science and Technology, Soochow University, Suzhou 215006, China
Ying-Lin Song
School of Physical Science and Technology, Soochow University, Suzhou 215006, China
Heng Wang
College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518071, China
Zheng Niu
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
Xiaopeng Li
College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518071, China
Brendan F. Abrahams
School of Chemistry, University of Melbourne, Victoria 3010, Australia
Pierre Braunstein
Université de Strasbourg-CNRS, Institut de Chimie (UMR 7177 CNRS), 4 Rue Blaise Pascal CS 90032, 67081 Strasbourg, France
Jian-Ping Lang
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China; State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
Designing and building unique cage assemblies attract increasing interest from supramolecular chemists but remain synthetically challenging. Herein, we propose the use of a flexible vertex with adjustable angles to selectively form highly distorted tetrahedral and octahedral cages, for the first time, in which the flexible vertex forms from the synergistic effect of coordination and covalent interactions. The inherent interligand angle of the vertex can be modulated by guest anions present, which allows for the fine-tuning of different cage geometries. Furthermore, the reversible structural transformation between tetrahedral and octahedral cages was achieved by anion exchange monitored by mass spectrometric technique, the smaller anions favoring tetrahedral cages, while the larger anions supporting octahedral cages. Additionally, the KBr-based cage thin films exhibited prominent enhancement of their third-order NLO responses in two or three orders of magnitude compared to those obtained for their corresponding solutions. This work not only provides a new methodology to build irregular polyhedral structures in a controlled and tunable way but also provides access to new kinds of promising functional optical materials.
