221208-78-2Relevant academic research and scientific papers
Molecular Imprinting Inside Dendrimers
Zimmerman, Steven C.,Zharov, Ilya,Wendland, Michael S.,Rakow, Neal A.,Suslick, Kenneth S.
, p. 13504 - 13518 (2007/10/03)
Synthetic hosts capable of binding porphyrins have been produced by a mixed-covalent-noncovalent imprinting process wherein a single binding site is created within cross-linked dendrimers. Two synthetic hosts were prepared, using as templates 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin and 5,10,15,20-tetrakis(3,5-dihydroxyphenyl)porphyrin. These two templates were esterified with, respectively, fourth- and third-generation Frechet-type dendrons containing homoallyl end-groups. The resulting tetra-and octadendron macromolecules underwent the ring-closing metathesis reaction using Grubbs' Type I catalyst, RuCl2(P(C6H5) 3)2(CHCH2C6H5), to give extensive interdendron cross-linking. Hydrolytic removal of the porphyrin cores afforded imprinted hosts whose ability to bind porphyrins with various peripheral substituents was investigated by UV-visible spectrophotometric titrations and size exclusion chromatography. The results indicate a high yield of imprinted sites that show high selectivity for binding of porphyrins capable of making at least four hydrogen bonds, but only a moderate degree of shape selectivity.
