C-13 NMR spectra of structurally characterized different types of 1,3-dicar
boxylato tetraorganodistannoxanes have been reported. In the solid state sp
ectra, separate resonances for carbonyl carbons have been observed for dist
inctly bonded carboxylate groups in the molecule whereas a single resonance
has been observed in solution. Variable temperature C-13 NMR data indicate
that these molecules adopt a dynamic stereochemistry in solution.