Molecule-ion interaction and its effect on electrostatic interaction in the system of copper chloride and β-cyclodextrin.
The present work was devoted to an experimental investigation of the molecule-ion interaction between copper chloride (CuCl(2)) and β-cyclodextrin (CD) and its effect on the electrostatic interaction between Cu(2+) and Cl(-) ions. Our results gave an explicit description of the mutual effect between the interactions. First, the molecular arrangement and surface feature of β-CD experienced a fundamental structural change after interaction with Cu(2+) and Cl(-) ions, which was ascribed to a good separation of Cu(2+) from Cl(-) ions in β-CD matrix. Second, arguments based on electronic structural analysis provided a direct indication of the change in charge density distributions of Cu(2+) and Cl(-) ions in the presence of β-CD. Third, the actual occurrence of a second signal in the course of water release at a higher temperature suggested that the Cu(2+) ions were trapped in the form of hydrates in the crystal interstice of β-CD molecules. Fourth, comparison of the mass spectra indicated that the thermal decomposition of β-CD in the presence of CuCl(2) produced a series of interesting molecular ions: C(3)H(2)OH(+), C(4)H(3)OH(+), C(5)H(4)OH(+), and C(7)H(6)OH(+). We consider that this study is helpful in providing a new approach to the evaluation of the extent of the mutual effect between an inorganic salt and an organic molecule.
Department of Chemistry, University of Science and Technology of China, Hefei 230026, PR China. solexin@ustc.edu.cn
Le Xin
le X
Song
Jing
J
Yang
Lei
L
Bai
Fang Yun
FY
Du
Jie
J
Chen
Mang
M
Wang