^1H ^13C NMR investigation of E/Z-isomerization around C=N bond in the trans-alkene-Pt(II)imine complexes of some ketimines and aldimines

Ketimines (k1, k2) and aldimines (a1, 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, ptk1, ptk2, pta1, pta2, and pta3. ^1h, ^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.