News Resource: School of Chemistry and Chemical Engineering

Editor: News Agency of BIT

Translator: Shao Yikang, News Agency of BIT

Beijing Institute of Technology, November 11th, 2021: Recently, Special Researcher, Yao Zishuo from School of Chemistry and Chemical Engineering of BIT, obtained great progress in the study of flexible molecular-based crystalline functional material. The relevant research achievements were entitled “Giant single-crystal-to-single-crystal transformations associated with chiral interconversion induced by elimination of chelating ligands”, appearing in the internationally recognized journal Nature Communications. BIT is the only author’s affiliation. Professor Tao Jun and Special Researcher Yao Zishuo from the School of Chemistry and Chemical Engineering were the joint corresponding author. And the lead author was doctoral candidate Li Yun. Professor Xie Jing offered help in terms of computation.

Molecule is the basic unit to compose molecular materials, and the structural basis that determines the materials’ physical properties as well. By stimulating crystal externally, the inner molecular structure’s changing can regulate materials’ physical properties like force, magnetism, electricity and light, which provide effective solution for designing and developing molecular mechanism dynamic material, storage medium and adjustable photoelectric material.

Fig.1:Two-step reversible single crystal to single crystal structure transformation.

Fig.2 Two-step reversible SCSC transformation associated with symmetry variation

The research team is based on the previous research on the control of material force and magnetic physical properties through molecular orientation changes , including Nat. Chem. , 2014, 6, 1079-1083； Nat. Commum. 2019, 10, 4805-4812； Angew. Chem., Int. Ed. 2017, 56, 717-721. combined with the recent reportson the induction of crystal lattice changes by guest molecules, the team put forward the research idea of driving single crystals to single crystals by peeling off weak chelating ligands, and later acquired the first giant and reversible single-crystal-to-single-crystal transmission based on simple chelating ligands detachment and crystalline structure condensed induction. Through the two-step separation/adsorption of the ethylene glycol chelating ligand，the volume of the material can be reversibly stretched by up to 50%，and the mass can be reversibly exchanged by 36%.The volume and mass changes have reached the maximum value of single crystal to single crystal transformation reported in the current literature。At the same time, during the separation process of the chelating ligand, the adjacent coordination sites of the metal center are released in space, and the molecular chirality is reversed. The corresponding single crystal material undergoes a two-step reversible symmetry change of central symmetry-helical chiral structure-polar structure. The symmetry variation was specifically examined by single-crystal-ray diffraction temperature-variable second-order nonlinear optic，and CD spectroscopy. The author analyzed the molecular motion mechanism of structural variation deeply based on comparisons of the single-crystal’s symmetry variation. This kind of single-crystal material possessing a gel-like property not only provides a creative way to compound flexible molecular-based monocrystalline material, but also reveals a possible solid-state reaction method for preparing chiral compounds via the elimination of chelating ligands.

Paper link: https://www.nature.com/articles/s41467-021-27282-9

Bi-stable functional material research group profile attached:

Tao Jun is a distinguished professor from School of Chemistry and Chemical Engineering of BIT, principally engaging in the research of molecular magnetism and journal of functional materials. And, he has published several high-level academic papers in Chem.Soc.Rev. ,J.Am.Chem.Soc. ,Angew.Chem., Int.Ed., Nat.Commun and other authoritative journals.

Yao Zishuo is the specialresearcher from School of Chemistry and Chemical Engineering of BIT, doctor and post-doctoral at Kyushu University. He is mainly engaged in the research of flexible molecular-based crystalline functional material such as force, magnetism and electricity. And, as the lead author or corresponding author, he has published more than 20 academic papers in Nat.Chem., Nat.Commun, J.Am.Chem.Soc., Angew.Chem., Int.Ed., CCS.Chem. and other authoritative journals.

Homepage of the research group: http://www.tao-lab.cn/