In:
Canadian Journal of Chemistry, Canadian Science Publishing, Vol. 79, No. 7 ( 2001-07-01), p. 1101-1104
Abstract:
Fluorescence enhancement of a probe molecule in solution by the container molecule cucurbituril (CB) is reported for the first time. The fluorescence of the probe 2-anilinonaphthalene-6-sulfonate (2,6-ANS) in aqueous Na 2 SO 4 solution is found to increase by a maximum factor of 5.0 upon addition of cucurbituril. This fluorescence enhancement is the result of the formation of a hostguest inclusion complex, in which the guest 2,6-ANS is incorporated inside the cavity of the host, cucurbituril. Measurement of the enhancement as a function of cucurbituril concentration yielded a value of the equilibrium constant (K) of 52 ± 10 M 1 . It is proposed that the mode of inclusion involves the phenyl group of the 2,6-ANS, because of the relatively small size of the cucurbituril cavity. It is further proposed that the observed enhancement is a result of loss of rotational mobility of the phenyl ring relative to the naphthyl fluorophore of 2,6-ANS upon inclusion of the phenyl ring. Since the name cucurbituril is derived from the Latin word for "pumpkin," this fluorescent host-guest complex is referred to as a "molecular Jack O'Lantern," with the 2,6-ANS serving as the candle.Key words: hostguest chemistry, fluorescence, cucurbituril, inclusion compounds.
Type of Medium:
Online Resource
ISSN:
0008-4042
,
1480-3291
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
2001
detail.hit.zdb_id:
1482256-8
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