Synthesis, characterization and crystal structures of platinum(II) saccharinate complexes with 1,5-cyclooctadiene.

Ceyda İçsel

doi:10.3906/kim-2002-34

Abstract

Two new platinum(II) complexes, namely [PtCl(sac)(COD)] (1) and [Pt(sac)2(COD)] (2) (sac = saccharinate and COD = 1,5-cyclooctadiene), were synthesized and characterized by elemental analysis, IR, NMR, ESI-MS spectroscopic and thermal analysis (TG/DTA) methods. The platinum(II) complexes were prepared from the reaction of [PtCl2(COD)] with Na(sac)•2H2O. The addition of the sac ligand resulted in the replacement of 1 and 2 chlorido ligands in [PtCl2(COD)] to yield 1 and 2, respectively. The structures of the complexes were determined by single crystal X-ray diffraction and showed a distorted square planar coordination geometry around platinum(II). COD acted as a π-donor ligand, while sac was N -coordinated in both complexes. The TG/DTA data indicated that both complexes were thermally stable up to 220 °C in air and their thermal decompositions yielded Pt as a final product. Complexes 1 and 2 were also designed as possible precursors to synthesize new mixed-ligand platinum(II) sac complexes in a one-pot reaction.

Highlights

After the discovery of the cell growth inhibition effect of cisplatin by Rosenberg [1,2,3], the design and synthesis of new platinum(II) complexes received increasing attention
The platinum(II) ion shows a distorted square planar coordination geometry defined by the mid-points of the 2 π -coordinated double bonds of chlorido ligands in [PtCl 2 (COD), 1 chloride and 1 N -bonded sac anion in 1, and 2 N -coordinated sac ligands in 2 (Figure 2)
Two new platinum(II) complexes containing COD and sac ligands were successfully synthesized via the progressive replacement of the chloride ligands in [PtCl 2 (COD)] by the sac ligand

Summary

Introduction

After the discovery of the cell growth inhibition effect of cisplatin by Rosenberg [1,2,3], the design and synthesis of new platinum(II) complexes received increasing attention. The chlorido ligands in the precursor can be exchanged by another ligand to yield the desired platinum(II) complex. The synthetic method seems to be an attractive alternative way to synthesize new platinum(II) sac complexes, because it may be regarded as a one-pot reaction with high yields. [PtCl(sac)(COD)] (1) and [Pt(sac) 2 (COD)] (2) were designed as starting materials for the synthesis of new mixed-ligand platinum(II) complexes of sac.

Results

Conclusion