Selective Pseudo-Rotaxane Type Complex Formation of Zinc(II) (t-butylatedtetraphenyl) porphyrin-Viologen Linked Compounds with tri-O-methyl-尾-Cyclodextrin
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- 作者：Tatsuya Morozumi ; Nao Sato and Hiroshi Nakamura
- 关键词：pseudo ; rotaxane type complexation ; supramolecular structure ; tri ; O ; methyl ; β ; cyclodextrin ; zinc(II) (t ; butylatedtetraphenyl)porphyrin ; viologen linked compounds
- 刊名：Journal of Inclusion Phenomena and Macrocyclic Chemistry
- 出版时间：October, 2006
- 出版年：2006
- 期刊代码：19_09230750
- 类别：soc
- 卷：56
- 期：1-2
- 页码：141-148
- 数据来源：sp
摘要
Inclusion complexation behavior of 2,3,6−tri-O-methyl-β-cyclodextrin (TM-β-CD) with zinc(II) 5,10,15-tri-(4-t-butyl-phenyl)-20-(4-(n-alkyloxy)phenylporphyrin covalently linked with violgen by a polymethylene chain (Zn-t-bu-PC n V2+; n=4, 6, 8, 10 and 12) was investigated by means of 1H NMR, UV/Vis absorption spectroscopies in acetonitrile-water (1:1, v/v). The 1H NMR spectra indicated that Zn-t-bu-PC n V2+ presumably existed as a mixture of a dimer and a monomer in high concentration (>1脳10−3 mol dm−3), and the dimer was degraded by the complex formation with TM-β-CD. The 1H NMR spectra of these compounds as a function of [TM-β-CD] showed the selective formation of 1:1 (=Zn-t-bu-PC n V2+: TM-β-CD) pseudo-rotaxane type complexes. The chemical modification by t-butyl groups on porphyrin showed a good protective effect on inclusion of benzene groups into the TM-β-CD cavity. These rotaxane formation constants (K) were determined by titration studies using UV/Vis absorption spectroscopy. These complex formation constants were somewhat affected by the spacer methylene chain between the porphyrin and viologen. The value of K for Zn-t-bu-PC4V2+路TM-β-CD is 1.0脳103 M−1 which is the smallest whereas those for Zn-t-bu-PC n V2+路TM-β-CD (n=8, 10, 12) were similar (1.0脳104 M−1).