Study on supramolecular systems of Mg-meso-tetrakis(2-thienyl)porphyrin with cyclodextrins by spectroscopy method

摘要

In phosphate buffer solution of pH 5.4, the formation of supramolecular systems of Mg-meso-tetrakis(2-thienyl)-porphyrin(Mg-TTP) with beta-CD, carboxymethyl-beta-CD (CM-beta-CD), heptakis(2,6-di-O-methyl)-beta-CD (DM-beta-CD), heptakis(2,3,6-tri-O-methyl)-beta-CD (TM-beta-CD) and sulfurbutylether-beta-CD (SBE-beta-CD) has been studied by means of UV-vis, fluorescence and NMR spectroscopy, respectively. And the Mg-TTP can form 1:1 host-guest inclusion complexes with five cyclodextrins. In this paper, the inclusive capability of different kinds of cyclodextrins is compared. The inclusion ability of modified beta-CD with Mg-TTP is stronger than the native beta-CD. And the inclusion ability of TM-beta-CD with Mg-TTP is the strongest among five CDs, which indicates that the hydrophobic effect plays a crucial role in the inclusion procedure except for the capacity matching. In addition, H-1-NMR data and 2D-ROESY NMR spectra support the inclusion conformation of the TM-beta-CD-Mg-TTP supramolecular system, indicating the interaction mechanism of inclusion processes.