学术报告：Spectral Signatures of Chirality, Chirality Recognition, and Chirality Transfer（Yunjie Xu）

Spectral Signatures of Chirality, Chirality Recognition, and Chirality Transfer

Yunjie Xu

Department of Chemistry, University of Alberta, Edmonton, AB, Canada, T6G 2G2

Email: yunjie.xu@ualberta.ca

Chirality, or “handedness”, is an intrinsic property of most biological molecules, and chirality recognition events are at the heart of many biological functions. Noncovalence interactions involving chiral molecules and water molecules play an essential role in life sciences since nearly all important biomolecules are chiral and most biological events take place in an aqueous environment. Our research focuses on applying and developing new spectroscopic tools to determine chirality and to establish chirality recognition models at the molecular level.

Chiroptical spectroscopy, such as electronic circular dichroism (ECD) and vibrational CD (VCD), can provide not only rich structural information such as absolute configuration and conformational distribution of chiral molecules in solution, but also important insights into how they interact with each other and with solvent molecules. I will discuss our recent ECD and VCD studies of a series of transition metal complexes,¹ a triple axial binaphthyl based ligand,² and chiral amine borane complexes.³ The effects of solvent and concentration on the resulting helicity and conformational distribution will be emphasized and the unique VCD spectral signatures for dihydrogen bonds will be highlighted.

In the second part, I will focus on the water hydrogen-bonding network surrounding a chiral molecule and our proposed “clusters-in-a-liquid” approach for simulating chiroptical spectra in water. The link between the small gas phase clusters and the solvation model^4,5 and the importance of including the bulk water environment using the polarizable continuum model⁶ will be discussed. Simulated VCD and Raman optical activity (ROA) spectra of carbohydrates in water using this approach will be presented.

This work was funded by the University of Alberta, the Natural Sciences and Engineering Research Council (NSERC) of Canada, Canada Foundation for Innovation, Alberta Enterprise and Advanced Education, and Compute Canada. YX holds a Tier I Canada Research Chair in Chirality and Chirality Recognition.

[1] Z. Dezhahang, M. R. Poopari, J. Cheramy, Y. Xu, Inorg. Chem. 2015, 54, 4539; C. Merten, R. McDonald, Y. Xu, Inorg. Chem. 2014, 53, 3177.

[2] Z. Dezhahang, M. R. Poopari, F. E. Hernández, C. Diaz, Y. Xu, Phys. Chem. Chem. Phys. 2014, 16, 12959.

[3] C. Merten, C. J. Berger, R. McDonald, Y. Xu, Angew. Chem. Int. Ed. 2014, 53, 9940.

[4] J. Thomas, O. Sukhorukov, W. Jäger, Y. Xu, Angew. Chem. Int. Ed. 2014, 53, 1156.

[5] C. Merten, Y. Xu, Angew. Chem. Int. Ed. 2013, 52, 2073; J. Thomas, O. Sukhorukov, W. Jäger, Y. Xu, Angew. Chem. Int. Ed. 2013, 52, 4402.

[6] M. R. Poopari, P. Zhu, Z. Dezhahang, Y. Xu, J. Chem. Phys. 2012, 137, 194308/1-7.