Chelating ligands organotin structures

The pentacoordinate organotin compounds 416a-c also contain a tridentate dianionic N,N,0-chelate ligand . The structure of 416c was determined by X-ray diffraction which conformed the rigid polycyclic structure proposed on the basis of H, B, C, and Sn NMR data in solution (S Sn —150.4 ppm) . In contrast, the dimethyltin compound 416a displays a fluxional structure in solution. 

CHART 1. The structures of organotin and organolead complexes of the type 387 containing monoanionic X,D-chelating ligands (X, D = N, O, S)... 

Valuable information concerning the structures in solution of organotin compounds containing a C,N-chelating ligand is obtained from H, l3C, and 119Sn NMR spectroscopic studies. Furthermore, these studies provide sometimes detailed information on the fluxional processes that are operative in solutions of these compounds. It appears that the 119Sn chemical... 

The complexes of aromatic hydroxy carboxylic acids (salicylic acid and its isomers) with [Bu2Sn(IV)] and [Ph3Sn(IV)] were obtained. The FT-IR and Raman spectra clearly demonstrated that the organotin(IV) moieties react with the O, O) atoms of the ligands. It was found that in most cases the -COO group chelated to the central atoms, but monodentate coordination was also observed. The complexes probably have polymeric structures. 

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