Design of differently P-substituted 4iPO fluorescent tetraphosphonate cavitands

Abstract

Experimental approaches to tetraphosphonate cavitands bearing fluorenyl-phosphonate bridges are reported. Different routes are described depending on the substitution on the cavitand structure. Tetra-, tri- and di-bridged phosphonate cavitands have been prepared as precursors of fluorescent hosts, for which the stereochemistry is highly dependent on the substitution at the wide rim of the resorcin[4]arene scaffold. The conformational change in 3io tetraphosphonate cavitands has been characterised by X-ray diffraction. These new molecular receptors have been used for the recognition of acetylcholine.

Keywords::

• host–guest chemistry
• molecular recognition
• phosphonate cavitand
• acetylcholine
• fluorescence

Acknowledgements

The authors warmly thank B. Basler, E. Gaume and Dr A.-G. Valade for their assistance in this project. Dr E. Jeanneau is greatly acknowledged for his help in X-ray diffraction analysis.