Significant Phenomena Observed in the Molecule-Ion Adduct System of Sodium Arsenite with aoCyclodextrin

The data of 1H nuclear magnetic resonance and molar conductivity prove that there is a molecule-ion interaction between a-cyclodextrin （a-CD） and sodium arsenite （SA）, and the interaction site is different from that between β-CD and SA. The packing mode of a-CD molecules after adduct with SA is changed from cage to channel type. Several experimental phenomena from thermogravimetric analyses and gas chromatography coupled to time-of-flight mass spectrometry measurements reveal that the presence of SA has led to a large change of thermal decomposition behavior of a-CD, and vice versa. The current work reveals the particularity of the interaction between SA and a-CD, which would provide new insight into the understanding of molecule-ion interactions.