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

Eurobic9, 2-6 September, 2008, Wrocław, Poland
P211. Polymorphic Forms of Zn(II) Compound with Biological Active
Diethyl (Pyridin-3-Ylmethyl)Phosphonate
(3-Pmpe) Ligand: Zn(3-Pmpe)Cl2
B. Żurowska a , K. Ślepokura a , T. Lis a , J. Ochocki b
a Faculty of Chemistry, University of Wroclaw, 50-383 Wroclaw, Poland
b Department of Bioinorganic Chemistry, Faculty of Pharmacy, Medical University, 90-151 Lodz, Poland
e-mail: zurowska@wchuwr.pl
Zinc is one of the most important trace elements playing a versatile role in biological systems due to its structural
and catalytic roles in enzymes. On the other hand, cis-Platinum(II) complexes of N-heterocyclic phosphonate
ligands exhibit biological activity [1, 2]. Therefore we have now studied spectroscopy and the crystal structures
of different crystalline forms of the compound of the empirical formula Zn(3-pmpe)Cl2.
X-ray analyses show that in the reaction of ZnCl2 with didentate ligand diethyl (pyridin-3-ylmethyl) phosphonate
(3-pmpe) in methanol three crystalline polymorphs are formed: [Zn(3-pmpe)Cl2]2 (1) and [Zn(3-pmpe)Cl2]n (2
and 3). In these crystals 3-pmpe acts as a didentate N, O-bridging ligand and Zn(II) are in a slightly distorted
tetrahedral ZnNOCl2 environment. Zn(II) ions in 1 are doubly bridged by the 3-pmpe ligands, resulting in the
formation of dinuclear species. In polymeric compounds 2 and 3 Zn(II) ions are singly bridged by the 3-pmpe,
resulting in the formation of one-dimensional chains.
1 2
Crystals of compound 1 are triclinic, space group P1̅, Z = 2, with cell parameters: a = 8.228(2),
b = 8.982(2), c = 10.329(3) Å, α = 78.97(3), β = 89.92(3), γ = 81.04(3)º, V = 739.8(3) Å 3 .
Crystals of compound 2 are monoclinic P21, Z = 4, with cell parameters: a = 7.742(2),
b = 28.246(6), c = 7.864(2)Å, β = 117.60(3)º, V = 739.8(3) Å 3 .
The third polymorphous form (polymeric 3) is triclinic, P1̅, Z = 2 with cell parameters: a = 8.850(3) Å,
b = 9.060(4) Å, c = 10.305(4) Å, α = 113.50(4)°, β = 98.91(3)°, γ = 95.27(3)°, V = 1524.0(6)Å 3 .
References:
[1] K. Aranowska, J. Graczyk, L. Chęcińska, W. Pakulska, J. Ochocki, Pharmazie 61 (2006) 457.
[2] B. Kostka, J. Sikora, K. Aranowska, J. Para, J. Ochocki, Acta Toxicologica 13 (2005) 113.
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