NMR characterisation and dynamic behaviour of [Pt(bipy)(R-Thiourea)2]Cl2 and [Pt(phen)(R-Thiourea)2]Cl2 complexes

We have recently reported the synthesis, characterisation and dynamic behaviour of 10 [Pd(bipy)(R-TU)2]Cl2 and [Pd(phen)(R-TU)2]Cl2 (bipy = 2,2′-bipyridyl; phen = 1,10-phenanthroline; R-TU = N-alkyl substituted thioureas) complexes; in this paper PtII analogues are presented to achieve a complete overview on this class of molecules. As expected, PtII derivatives increase the rotation barrier about the thioureas C-N bonds and once again the metal has proved to select preferential conformations for both mono and dialkyl thioureas. In this study, beyond the many shared features of the 20 PtII and PdII complexes, we extensively issue all the data concerning 13C, 15N and 195Pt hetero-nuclear NMR, stressing out the chemical shift differences that any free ligand undergoes upon coordination. To achieve this goal all the hetero-nuclear experiments were performed for the 7 free ligands and the 20 complexes in the same experimental conditions. Further support to the determined structures and dynamics is provided by mass spectrometry measurements by an ion-trap time-of-flight (IT-TOF) detector.