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Anisotropy of the fluorescence from the monomer, five oligomers, and a polymer of epicatechin
Author(s) -
Cho Donghwan,
Mattice Wayne L.,
Porter Lawrence J.
Publication year - 1990
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360290109
Subject(s) - random hexamer , monomer , chemistry , dimer , dispersity , polymerization , fluorescence , degree of polymerization , oligomer , ethylene glycol , polymer , crystallography , anisotropy , molecule , polymer chemistry , organic chemistry , quantum mechanics , physics
The steady‐state fluorescence anisotropy r has been measured at 25°C for dilute solutions of epicatechin units connected by interflavan bonds with 4β → 8 stereochemistry. The molecules studied are monodisperse oligomers from the monomer through the hexamer, and a polydisperse sample with a number‐average degree of polymerization x n of 10. The hexamer and smaller oligomers have been removed from the polydisperse sample. All samples have a very small value of r in 1,4‐dioxane and in methanol. Higher values of r are seen in ethylene glycol and in glycerol. In the latter two solvents, the monomer has significantly higher r than any species with x n > 1. This observation is interpreted as evidence for the presence of excitation migration from one monomer to another in the dimer and species of higher x n .