Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (07): 1579-1586.doi: 10.3866/PKU.WHXB20110727

• THERMODYNAMICS, KINETICS, AND STRUCTURAL CHEMISTRY • Previous Articles     Next Articles

Formation, Structure and Thermal Degradation of the Supramolecular Complex between β-Cyclodextrin and 18-Crown-6

ZHU Lin-Hong1, SONG Le-Xin1,2, CHEN Jie1, YANG Jing1, WANG Mang1   

  1. 1. Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China;
    2. State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, P. R. China
  • Received:2011-03-14 Revised:2011-05-13 Published:2011-06-28
  • Contact: SONG Le-Xin E-mail:solexin@ustc.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21071139).

Abstract:

The formation of a 1:1 supramolecular complex between β-cyclodextrin (β-CD) and 18- crown-6 (18C6) by simply mixing them was confirmed by elemental analysis, 1H nuclear magnetic resonance (1H NMR) and electrospray ionization mass spectrometry. The probable interaction sites between these species were determined by two-dimensional rotating frame nuclear Overhauser effect spectroscopy (ROESY), which showed that 18C6 tended to be located on the narrow end of the cavity of β-CD. Also, the degradation process including the degree of degradation and the degradation products of the complex was carefully compared with those of β-CD and 18C6 through thermogravimetric analysis and gas chromatography coupled to time-of-flight mass spectrometry. The experimental data indicated that the presence of 18C6 resulted in an earlier degradation of β-CD. Furthermore, the relative abundance of larger fragments from the degradation process of the two components was reduced drastically because of an intermolecular interaction. These results strongly indicate that a supramolecular complex can be constructed using the flexible macrocyclic molecule 18C6 as a guest and the rigid macrocyclic molecule β-CD as the host via molecular assembly between them.

Key words: β-Cyclodextrin, 18-crown-6, Nclusion complex, Intermolecular interaction, Supramolecule, Molecular assembly

MSC2000: 

  • O643