Anion complexation by calix[3]thieno[1]pyrrole: the medium effect.
The interaction of calix[3]thieno[1]pyrrole, 1, and halide and dihydrogen phosphate anions in a variety of solvents (acetonitrile, propylene carbonate, N,N-dimethylformamide, and dimethyl sulfoxide) has been investigated through 1H NMR, conductance measurements, and titration calorimetry. 1H NMR measurements reveal the sites of interaction of the ligand with the anions in CD3CN while the composition of the complex was determined through conductance measurements. A quantitative assessment of anion-ligand interactions is provided. Thus the thermodynamics of complexation of 1 with halide and dihydrogen phosphate anions in dipolar aprotic media at 298.15 K is reported. These data are interpreted in terms of the thermodynamics of transfer of reactants and product from a reference solvent (acetonitrile) to other solvents. The crucial role played by the solvent on the ability of the ligand to interact with anions and on the composition of the complex is demonstrated.
Danil de Namor
Angela F
AF
Laboratory of Thermochemistry, Chemistry Division, School of Biomedical and Molecular Sciences, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom.
Abbas
Ismail
I
Hammud
Hassan H
HH
D000097:Acetonitriles / Q000737:chemistry; D000838:Anions / Q000737:chemistry*; D047250:Calixarenes / Q000737:chemistry*; D003217:Conductometry; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D004126:Dimethylformamide; D005559:Formamides / Q000737:chemistry; D006846:Hydrocarbons, Halogenated / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010710:Phosphates / Q000737:chemistry; D011407:Propane / Q000031:analogs & derivatives / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013816:Thermodynamics; D013876:Thiophenes / Q000737:chemistry*
D000097:Acetonitriles; D000838:Anions; D005559:Formamides; D006846:Hydrocarbons, Halogenated; D008024:Ligands; D010710:Phosphates; D011758:Pyrroles; D012997:Solvents; D013876:Thiophenes; C513690:calix(3)thieno(1)pyrrole; D047250:Calixarenes; D004126:Dimethylformamide; C045990:propylene carbonate; D011407:Propane; D004121:Dimethyl Sulfoxide; C032159:acetonitrile