IJUP08 - Universidade do Porto

DFT STUDY ON THE ABILITY OF CALIX[2]FURANO[2]PYRROLE
TO FORM HOST-GUEST COMPLEXES WITH DIFFERENT IONS
C.A. Teixeira dos Santos, and A.L. Magalhães
Department of Chemistry, Faculty of Science, University of Porto, Portugal.
The applications of calixarene derivatives as new receptors have attracted considerable
interest in the area of host-guest chemistry[1]. The presence of sulfur or nitrogen atoms in
the ring linkages or upper rim seems to greatly enhance the complexation abilities toward
transition metal ions, when compared to the classical calixarene systems. Applications of
these molecules as new receptors, building blocks and /or molecular platforms have
attracted considerable interest in a wide range of areas such as host-guest chemistry,
separation chemistry, environment protection, selective ion transport and sensors [1].
Recently, DFT methods have been applied successfully in the study of the structural
features and conformational equilibrium of sulfur bridged derivative compounds[2].
This work presents a comparative study of the complexation ability of
calix[2]furano[2]pyrrole toward different positive ions. The B3LYP/SDD[3] level was
used to estimate the binding energy of the host-guest 1:1 complexes between the cone
conformer of calix[2]furano[2]pyrrole (1) and the alkaline ions Li+, Na+, K+, Rb+, Cs+,
the alkaline-earth ions Be2+, Mg2+, Ca2+, Sr2+, Ba2+, and also the transition metal ions
Ag+, Cu2+, Zn2+, Hg2+ and Au3+ as well.
The theoretical predictions are compared with available experimental data[3]. Structural
and electronic characteristics are presented, in order to support some experimental results
and to discuss the different ability of the ligand to form complexes with the ions under
study.
NH
O
(1)
References:
[1]Lhoták P., Eur. J. Org. Chem., 2004, 1675-1692.
[2]Suwattanamala A., Magalhães A.L., Gomes, J.A.N.F., Theor. Chem. Acc., 2007,117, 431-440
[3]Lim S.M., Chung HJ, Paeng K, Lee C., Choi H.N., Lee W., Anal. Chim. Acta., 2002, 453, 81-
88.
O
NH
140