Premium
Carboxymethylated cyclodextrins and their complexes with Pr(III) and Yb(III) as water‐soluble chiral NMR solvating agents for cationic compounds
Author(s) -
Provencher Katelyn A.,
Weber Madeline A.,
Randall Lauren A.,
Cunningham Patrick R.,
Dignam Catherine F.,
Wenzel Thomas J.
Publication year - 2010
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20748
Subject(s) - chemistry , cationic polymerization , indoline , enantiomer , cyclodextrin , lanthanide , substrate (aquarium) , nmr spectra database , proton nmr , combinatorial chemistry , organic chemistry , ion , spectral line , oceanography , physics , astronomy , geology
Cyclodextrins that are indiscriminately carboxymethylated at the 2‐, 3‐, and 6‐positions are used as chiral NMR solvating agents for cationic substrates with phenyl, naphthyl, pyridyl, indoline, and indole rings. Enantiodifferentiation with the α‐, β‐, and γ‐cyclodextrin derivatives is compared. The carboxymethylated derivatives are almost always more effective as chiral NMR solvating agents for cationic substrates than native cyclodextrins. The most effective carboxymethylated cyclodextrin varies for different substrates, and at times even different resonances of the substrate. Addition of paramagnetic praseodymium(III) or ytterbium(III) to mixtures of the carboxymethylated cyclodextrin and substrate often causes enhancements in enantiomeric discrimination and facilitates measurements of enantiomeric purity. The lanthanide ion bonds to the carboxymethyl groups and causes perturbations in the chemical shifts in the NMR spectra of substrate molecules in the cyclodextrin cavity. Chirality, 2010. © 2009 Wiley‐Liss, Inc.