Alberto Trevisan, Ana S. D. Ferreira, Philippe Marrec, A. Jorge Parola, Nuno Basílio
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引用次数: 0
Abstract
Cucurbiturils are popular macrocyclic receptors that bind complementary guest molecules with high affinity in aqueous environments. They are recognized for their ability to selectively bind positively charged guest molecules, including ionizable ammonium cations which frequently display much higher affinity than their neutral counterparts. This selectivity for the protonated species is translated into an increase in the basicity of encapsulated guests (i. e. into complexation-induced positive pKa shifts). However, despite being very rare, negative pKa shifts can be observed for specific guests. Following a previous work from our group reporting slightly negative pKa shifts for flavylium and chalcone dyes featuring N-diethylamino substituents (ΔpKa=− 0.2), herein we report a systematic study on the complexation of N-dialkylaminochalcones with CB7. The results show that the pKa shifts of these host-guest complexes can be rationally tuned by the nature of the N-dialkylamino groups and as well by target substitutions on the skeleton of the dye, allowing the design of a CB7 1 : 1 host-guest complex with a ΔpKa=− 0.6.
期刊介绍:
The fledgling State of Israel began to publish its scientific activity in 1951 under the general heading of Bulletin of the Research Council of Israel, which quickly split into sections to accommodate various fields in the growing academic community. In 1963, the Bulletin ceased publication and independent journals were born, with Section A becoming the new Israel Journal of Chemistry.
The Israel Journal of Chemistry is the official journal of the Israel Chemical Society. Effective from Volume 50 (2010) it is published by Wiley-VCH.
The Israel Journal of Chemistry is an international and peer-reviewed publication forum for Special Issues on timely research topics in all fields of chemistry: from biochemistry through organic and inorganic chemistry to polymer, physical and theoretical chemistry, including all interdisciplinary topics. Each topical issue is edited by one or several Guest Editors and primarily contains invited Review articles. Communications and Full Papers may be published occasionally, if they fit with the quality standards of the journal. The publication language is English and the journal is published twelve times a year.