ISSN:
0268-2605
Keywords:
diorganotin
;
Pyrimidine
;
complex
;
Mössbauer
;
IR
;
NMR
;
Chemistry
;
Industrial Chemistry and Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The complexes formed between the diorganotin(IV) moieties, R2Sn(IV), and the ligand 2-mercaptopyrimidine, (H)SPym, were investigated. Complexes R2SnHal(SPym) and R2Sn(SPym)2 [R = Me, iPr, nBu, iBu, tBu, cyclohexyl(Cy), Ph] were synthesized, and characterized by elemental analysis. In the solid state, chelation of SPym through S and N donors was established by IR spectroscopy, and the nature of the environment of tin centers was investigated by 119Sn Mössbauer spectroscopy. From the dynamics of 119Sn nuclei determined by variable-temperature measurements on representative compounds [Me2SnCl(SPym) and Cy2SnBr(SPym)], as well as by point-charge model treatment of nuclear quadrupole splitting parameters, it was inferred that Me2SnCl-(SPym) may assume a trans-Me2 octahedral coordination geometry around tin in a monodimensional polymer, or a monomeric trigonal-bipyramidal structure (distorted). The latter type of structure was assigned to the other R2SnHal(SPym) species, while R2Sn(SPym)2 complexes assume a trans-octahedral, or skew trapezoidal, tin environment. In CHCl3-CDCl3 solutions, monomeric species occur (according to vapor-pressure osmometry), where 1H and 13C NMR spectroscopic parameters of SPym indicate the persistence of Sn chelation by S and N donor atoms. The Me2SnCl(SPym) species assume trigonal-bipyramidal structures with a chelating SPym ligand, in CDCl3 and C2H5OH solutions, according to the coupling constants 1J(119Sn,13C), as well as IR and 119Sn Mössbauer spectroscopic data. 119Sn NMR parameters fully correspond with data for the homologous complexes with 2-mercaptopyridine. Copyright © 1998 John Wiley & Sons, Ltd.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
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