Send to

Choose Destination
Proc Natl Acad Sci U S A. 2009 Jun 30;106(26):10449-54. doi: 10.1073/pnas.0811663106. Epub 2009 Feb 23.

Molecular recognition and self-assembly special feature: Multipoint molecular recognition within a calix[6]arene funnel complex.

Author information

Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, Unité Mixte de Recherche 8601, Centre National de la Recherche Scientifique, Université Paris Descartes (Paris 5), 45 Rue des Saints-Pères, Paris, France.


A multipoint recognition system based on a calix[6]arene is described. The calixarene core is decorated on alternating aromatic subunits by 3 imidazole arms at the small rim and 3 aniline groups at the large rim. This substitution pattern projects the aniline nitrogens toward each other when Zn(II) binds at the Tris-imidazole site or when a proton binds at an aniline. The XRD structure of the monoprotonated complex having an acetonitrile molecule bound to Zn(II) in the cavity revealed a constrained geometry at the metal center reminiscent of an entatic state. Computer modeling suggests that the aniline groups behave as a tritopic monobasic site in which only 1 aniline unit is protonated and interacts with the other 2 through strong hydrogen bonding. The metal complex selectively binds a monoprotonated diamine vs. a monoamine through multipoint recognition: coordination to the metal ion at the small rim, hydrogen bonding to the calix-oxygen core, CH/pi interaction within the cavity's aromatic walls, and H-bonding to the anilines at the large rim.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center