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Anion Complexation by Glycocluster Thioureamethyl Cavitands: Novel ESI‐MS‐Based Methods for the Determination of K a Values
Author(s) -
Oshovsky Gennady V.,
Verboom Willem,
Fokkens Roel H.,
Reinhoudt David N.
Publication year - 2004
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200305612
Subject(s) - chemistry , acetonitrile , thiourea , electrospray ionization , cellobiose , titration , ion , organic chemistry , hydrolysis , cellulase
A series of saccharide‐thiourea functionalized cavitands was prepared in good yields (72–86 %) by reaction of a tetrakis(aminomethyl) cavitand with the thiocyanate derivatives of acetylated glucose, galactose, and cellobiose. The anion complexation behavior of the acetylated and deacetylated glycocluster thioureamethyl cavitands was studied with electrospray ionization mass spectrometry (ESI‐MS) in acetonitrile and in a 1:1 acetonitrile/water mixture, respectively. All compounds show a preference for Cl − . A linear relationship was found between the square root of the intensity and the concentration of the formed host–guest complex. Based on this relationship, novel methods have been developed to determine K a values, by means of direct titration and competition experiments.