Acta of the International Symposia on Metal Complexes – ISMEC Acta,
Volume 4 - ISMEC 2014, June 8th – 12th 2014 – Pavia (Italy)
Powerful Trident Scavengers for Some Alkali and Alkaline Earth Metal
Cations
Ines Despotović
Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Zagreb, 10000, Croatia
Ines.Despotovic@irb.hr
It is a common wisdom that macrocyclic ligands have the ability to selectively bind the metal
ions [1] which has proved to be very useful in ion transporting phenomena, chemosensing,
metaloenzyme mimics, catalysis, and nuclear waste treatments [2]. Among a large variety of
macrocycles synthesized to serve as scavengers of metal ions, calixarenes play a notable role.
This presentation reports on the results of the complexation of Li+, Na+ and Be2+ metal
cations with several derivatives of the parent N-(phenyl)-substituted azacalix[3](2,6)pyridine
(Figure 1), both in gas phase and in acetonitrile solution. The gas phase molecular structures
H
R1
H
H
N
C
H
C
N
C
N
N
C
N
C
R2
R2
I
N
C
H
R1
C
C
N4 N1 N5
X
C
C
N3 N2
II
III
C
C
N6
R1
H
R2
1
1a (R1=H, R2=Me)
1b (R1=R2=NMe2)
1c (R1=R2=[N=C(NMe2)2])
Figure 1 N-(phenyl)-substituted azacalix[3](2,6)pyridine scafold 1 and its derivatives 1a, 1b
and 1c serving as scavengers of cations X = Li+, Na+ and Be2+.
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Acta of the International Symposia on Metal Complexes – ISMEC Acta,
Volume 4 - ISMEC 2014, June 8th – 12th 2014 – Pavia (Italy)
and complexation energies were calculated by the B3LYP/6-311+G(3df,2p)//B3LYP/6-31G(d)
method including basis set superposition error (BSSE) calculated by counterpoise (CP)
correction scheme at the same level of theory. The solvent effects were assessed using the
polarized continuum method (PCM).
The results have shown that supramolecular structures 1a, 1b and 1c offer useful
ligands capable of efficient and selective sequestration of Li+, Na+ and Be2+ cations, being the
most suitable for the Be2+ cation. The binding affinity for Be2+ is extremely high, both in the
gas phase and in the acetonitrile [3], which might be very useful in prevention of berylliosis
desease.
References:
[1]
Lehn, J. M., Supramolecular Chemistry; VCH: Weinheim, 1995.
[2]
Izatt, R. M.; Bradshaw, J. S.; Nielson, S. A.; Lamb, J. D.; Christensen, J. J.; Sen, D.,
Chem. Rev. 1985, 85, 271-339.
[3]
Despotović, I.; Maksić, Z. B., Tetrahedron Lett. 2011, 52, 6263-6266.
Topic: Computational modeling
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