ISBN: 978-83-60043-10-3 - eurobic9

Eurobic9, 2-6 September, 2008, Wrocław, Poland
P89. Coordination Modes and Structural Aspects of Mixed-ligand
Copper(II) Complexes Containing Some Polyamines and Amino Acids
A. Kamecka a , K. Bogusz a , J. Jezierska . b , A. Woźna. a , B. Kurzak a
a Department of Chemistry, University of Podlasie, 3 Maj 54, 08-110, Siedlce, Poland
b Faculty of Chemistry, University of Wrocław, F. Joliot Curie 14, 50-383, Wrocław, Poland
Amino acids and peptides, which are the basic structural units of proteins, are potential chelating reagents for
copper(II) ion [1, 2]. There is continuing interest in coordination compounds of copper(II) with various
combinations of heterocyclic nitrogen, thiolate and thioether donors because of the coordination of copper to two
histidine nitrogen atoms and cysteine and methionine sulfur atoms in the electron transfer blue copper proteins
[3, 4]. Furthermore, in a number of biochemical processes copper(II) is involved in mixed-ligand complex
formation and ligand catalysed complex formation reactions [5]. Due to the fact that polyamines are found at a
significant concentration in young cells and, particularly, in cancer tumor tissues [6], it seems to be interesting to
investigate the ternary copper(II)-polyamine-histidine/methionine systems (the polyamines such as
ethylenediamine (en), diethylenetriamine (dien) or N, N, N’, N’’, N’’-pentamethyldiethylenetriamine
(Me5dien)). The stoichiometries, stability constants and bonding modes of the species formed at aqueous
solution in the copper(II) ternary systems have been established. Our spectroscopic results indicate the tetragonal
geometry for the mixed-ligand complexes of en, the geometry slightly deviated from square pyramidal for the
species of dien and strongly deviated from square pyramidal towards trigonal bipyramidal for the complexes of
Me5dien.
References:
[1] P. Deschamps, P.P. Kulkarni, M. Gautam-Basak, B. Sarkar, Coord. Chem. Rev., 249 (2005) 895.
[2] B.G. Malstrom, J. Leckner, Current Opinion in Chemical Biology, 2 (1998) 286.
[3] E.I. Solomon, M.J. Baldwin, M.D. Lowery, Chem. Rev. 92 (1992) 521.
[4] E.I. Solomon, R.K. Szilagyi, S.D. Georgie, L. Basumallick, Chem. Rev. 104 (2004) 419.
[5] H. Sigel, Metal Ions in Biological Systems, Vol.3, Marcel Dekker Inc., New York, 1974.
[6] C.W. Tabor, H. Tabor, Ann. Rev. Biochem. 53 (1984) 749.
_____________________________________________________________________
208