title: Study on the supramolecular systems of 5-(2-hydroxy phenyl)-10,15,20-tris (4-methoxy phenyl) porphyrin with cyclodextrins.
abstract: In neutral phosphate buffer solutions of pH 7.4, the inclusive complexation of 5-(2-hydroxy phenyl)-10,15,20-tris(4-methoxy phenyl) porphyrin (o-HTPP) with alpha-cyclodextrin (alpha-CD), beta-CD, heptakis (2,3,6-tri-O-methyl)-beta-CD (TM-beta-CD), SBE-beta-CD, HP-beta-CD and gamma-CD has been examined by means of UV-vis and fluorescence spectroscopy. The formation of inclusion complexes has been confirmed on the base of changes of spectroscopy properties. The o-HTPP forms 1:2 inclusion complexes with TM-beta-CD and 1:1 inclusion complexes with the other five cyclodextrins. The formation constants (K) of o-HTPP for the formation of the inclusion complexes have been estimated from the absorbance and fluorescence intensity changes in neutral phosphate buffer solutions. The K value (2.89x10(7)), which is the formation constant for the formation of the 1:2 inclusion supramolecular, is nearly 10(4) times than those of the 1:1 inclusion complexes. Compared to the other five cyclodextrins, the strongest inclusion ability of TM-beta-CD can be explained that the hydrogen bond plays significant role in the inclusion process. UV-vis experiments also showed that the cavity of TM-beta-CD causes the transform of the state of o-HTPP. In addition (1)H NMR data and 2D-ROSEY NMR spectra support the inclusion conformation of the o-HTPP-CD supramolecular system, indicating the interaction mechanism of inclusion processes.
authors.affiliation: Department of Chemistry, Shanxi University, Taiyuan, Shanxi 030006, PR China.
authors.forename: Ling-hong
authors.initials: LH
authors.lastname: Kong
authors.forename: Yu-jing
authors.initials: YJ
authors.lastname: Guo
authors.forename: Xiao-xiang
authors.initials: XX
authors.lastname: Li
authors.forename: Jing-hao
authors.initials: JH
authors.lastname: Pan
mesh_terms: D003505:Cyclodextrins / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D011166:Porphyrins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D047391:alpha-Cyclodextrins / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: C519061:5-(2-hydroxy phenyl)-10,15,20-tris (4-methoxy phenyl) porphyrin; D003505:Cyclodextrins; D011166:Porphyrins; D047391:alpha-Cyclodextrins; D047392:beta-Cyclodextrins; C031215:betadex; C032613:alpha-cyclodextrin