Affiliations: Department of Chemistry, Renmin University of China, Beijing, China | Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China | College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian, China | College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang, China | University of International Relations, Beijing, China | Department of Materials Science and Engineering, University of Delaware, Newark, DE, USA
Note:  Corresponding author: Yizhuang Xu, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China. E-mail: [email protected]
Abstract: Two-dimensional (2D) correlation spectroscopy provides an important approach to the study of subtle spectral variations caused by intermolecular interactions. In our previous work, DAOSD (Double Asynchronous Orthogonal Sample Design) scheme was introduced to analyze subtle spectral variations of characteristic peaks of substance under intermolecular interactions. In this paper, we apply DAOSD scheme to probe weak coordination between lanthanide (III) ions and lactone group of organic ligands from natural pharmaceutical. Weak coordinative interaction between Nd3+ and carbonyl group in Nd(ClO4)3/artemisinin in acetonitrile solutions is characterized by using 2D UV/IR hetero-correlation spectroscopy. Experimental results demonstrate that subtle band-shift and variation on the absorptivity can be observed on both carbonyl band of artemisinin and f–f transition band of Nd3+ ions upon coordination.