Back to the list of abstracts
Speciation 98: Abstracts
Hajnalka Jankovics1, Norbert Buzás1, László Nagy2, Roland Krämer3, Ernõ Kuzmann4, Attila Vértes4 and Kálmán Burger1
1 Research Group on Biocoordination Chemistry
of the Hungarian Academy of Sciences, A. József University,
H-6701 Szeged, P.O. Box 440, Hungary;
2 Department of Inorganic and Analytical
Chemistry, A. József University, Szeged, Hungary;
3 Department of Inorganic Chemistry, Westfälische
Wilhelms Universität, Münster, Germany;
4 Department of Nuclear Chemistry, L. Eötvös
University, Budapest, Hungary
In consequence of their structural variability, organotin(IV) derivatives of N-substituted amino acids and peptides have been extensively studied in recent decades. It is of particular interest to examine the structural variations caused by organic substituents on the tin and protecting groups on the amino nitrogen of the ligand. The present poster reports the influence of the presence and absence of side-chains and of their chemical character on the structure in triphenyltin(IV)+ complexes of some N-acetylamino acids.
In the course of the research triphenyltin(IV)+ complexes of N-acetylglycine, N-acetyl-L-cysteine, N-acetyl-L-leucine, N-acetyl-L-asparagine and N-acetyl-L-tyrosine were prepared by two methods and characterized by means of different spectroscopic methods (FTIR, Raman, multinuclear, 1H, 13C and 119Sn NMR and 119Sn Mössbauer). The spectroscopic data indicated that the N-acetylglycine complex adopts a trigonal-bipyramidal structure in which the monodentate carboxylate and the amide -C=O group are bound to the same organotin(IV) moiety. The N-acetyl-L-cysteine derivative is dimeric, with a metal to ligand ratio of 2:1. The bidentate carboxylate, the thiolate group and a methoxy moiety coordinate to different triphenyltin(IV) units in the latter complex, resulting in a two trigonal-bipyramidal tin centres. The other three complexes are linear oligomers in which the planar triphenyltin(IV) is coordinated axially by a monodentate carboxylate and an amide -C=O from two different ligands. At the C-terminal end of the oligomer chain there is a tetracoordinated tin(IV) with a monodentate carboxylate as donor group.
