Experimental and Theoretical Evidence of the Bidentate Binding Mode of Dichloroacetamido Groups at the Upper Rim of Calix[4]arene Hydrogen-Bonding Anion Receptors

Calix[4]arenes in the 1,3-alternate conformation ( 1 - 3 ) and bearing activated amide groups at the upper rim have been synthesized and their anion binding properties studied and compared with conformationally mobile ( 4 ) or cone ( Ib ) receptors having the same binding groups. Association constants determined in CDCl 3 show a stronger complexation for Y-shaped carboxylate anions and a higher efficiency for receptors ( Ib and 3 ) bearing dichloroacetamido moieties as hydrogen bonding donor groups. Molecular modeling studies performed on the cone derivative ( Ib ) and its 1,3-alternate isomer ( 10 ) and ab initio calculations on 4-methoxyaniline derivatives ( 11 - 13 ) used as simplified models, reveal that the α,α-dichloroacetamido moieties bind anions in a bidentate fashion using both the N-H and the CHCl 2 as hydrogen bonding donor groups. This explains the higher efficiency in carboxylate binding found for Ib and 3 that incorporate the dichloroacetamido binding unit in their structures.

[1]  F. Sansone,et al.  Thiourea-linked upper rim calix[4]arene neoglycoconjugates: synthesis, conformations and binding properties. , 2003, Organic & biomolecular chemistry.

[2]  C. Massera,et al.  A novel self-assembled supramolecular architecture involving cation, anion and a calix[4]arene heteroditopic receptor , 2002 .

[3]  I. Stibor,et al.  Urea derivatives of calix[4]arene 1,3-alternate: an anion receptor with profound negative allosteric effect , 2001 .

[4]  Philip A. Gale,et al.  Anion Recognition and Sensing: The State of the Art and Future Perspectives. , 2001, Angewandte Chemie.

[5]  P. Cozzini,et al.  Synthesis and Properties ofUpper Rim C-Linked Peptidocalix[4]arenes , 2001 .

[6]  D. Reinhoudt,et al.  Facilitated transport of hydrophilic salts by mixtures of anion and cation carriers and by ditopic carriers , 1999 .

[7]  S. Kang,et al.  Urea derivative of calix[4]diquinone: HSO4− ion selective receptor , 1999 .

[8]  K. Nam,et al.  Synthesis and Anion Binding Properties of Urea Derivatized p-tert-Butylcalix[6]arenes. , 1999 .

[9]  S. J. Loeb,et al.  Bis(amido)calix[4]arenes in the pinched cone conformation as tuneable hydrogen-bonding anion receptors , 1997 .

[10]  D. Reinhoudt,et al.  Solubilization of NaX Salts in Chloroform by Bifunctional Receptors , 1996 .

[11]  D. Reinhoudt,et al.  Upper-rim urea-derivatized calix[4]arenes as neutral receptors for monocarboxylate anions , 1996 .

[12]  D. Reinhoudt,et al.  Urea-derivatized p-tert-butylcalix[4]arenes: neutral ligands for selective anion complexation , 1994 .

[13]  D. Reinhoudt,et al.  Chlorosulfonylated calix[4]arenes : precursors for neutral anion receptors with a selectivity for hydrogen sulfate , 1993 .

[14]  A. Hamilton,et al.  Molecular recognition: hydrogen-bonding receptors that function in highly competitive solvents , 1993 .

[15]  D. Reinhoudt,et al.  Tetra-O-alkylated calix[4]arenes in the 1,3-alternate conformation , 1992 .

[16]  P. Nieto,et al.  Carbon-13 NMR chemical shifts. A single rule to determine the conformation of calix[4]arenes , 1991 .

[17]  D. Reinhoudt,et al.  The 1,2-alternate conformation of calix[4]arenes: a rare comformation? Dynamic $1$H NMR studies of flexible tetraalkylated calix[4]arenes , 1991 .

[18]  K. Friedrici.  Arsenmittel und Flugzeugbekämpfung , 1927 .