H C NMR investigation of ZsZ-isomerization around C=N bond in the trans-alkene-Pt(II)‎imine complexes of some ketimines and aldimines

Abstract EN

Ketimines (Kl, K2) and aldimines (Al, A2, and A3) were prepared from unsubstituted acetophenone and/or benzaldehyde and primary amines (I-PrNH2, I-BuNH2 and t-BuNH2).

These imines were reacted with Zeise's salt (potassium ethenetrichloroplatinate (II)) to produce the respective complexes, namely, PtKl, PtK2, PtAl, PtA2, and PtA3.

'H, 13C, and 195Pt-chemical shifts of the ligands and their complexes were studied to investigate the nature and mode of isomerization around C=N bond.

The aldimines and their complexes were obtained as a single isomer.

On the other hand, the ketimines and their complexes were obtained as a mixture of E / Z-isomers.

It was found that the aldimine- and ketimine-platinum complexes undergo slow E / Z-isomerization in solution as evidenced from NMR spectra.