195Pt-NMR-Messungen an stereoisomeren Chloro-Bromo-Platinaten(rV) / 195Pt NMR Studies on Stereoisomeric Chloro Bromo Platinates(IV)

195Pt NMR spectra for the pure anionic complexes [PtClnBr6-n]2-have been measured in acetone solution. The isomerization reactions cis-[PtClnBr6-n]2-→ trans-[PtClnBr6-n]2-, n = 2, 4 and fac-[PtCl3Br3]2-→ mer-[PtCl3Br3]2-are slow on the NMR time scale and these slow kinet ics allow an unambiguous assignment of the 195Pt signals. The cis and fac complexes are found at slightly lower field (12-15 ppm) than their trails and mer counter­parts. There is a linear correlation of δ 195Pt with the sum of the Allred-Rochow electronegatives of the halogen atoms.