Factors influencing cyclometalations in platinum(II) complexes with tertiary phosphine ligands.
|Year of publication||2016|
|MU Faculty or unit|
|Description||Intramolecular activation reactions of C-H bonds on aromatic rings are frequently studied in transition metal complexes since resulting cyclometalated complexes are tested and applied in variable areas of research.[1,2] However, factors influencing proclivity of single complex for cyclometallation are far from being fully understood. We recently performed study of cyclometallations in Pt(II) complexes with phosphinoamine and phosphinophenol ligands via C-H thermal activation to evaluate the importance of ligand substitution on the reactivity of the starting compounds. The presence and positioning (ortho and para) of the substituents combined with intramolecular hydrogen interactions were found to be crucial for a successful cyclometalation. We have therefore prepared a series of organophosphorus ligands and synthesized their cis-Pt(II) complexes from PtCl2(cod). By means of 31P NMR spectroscopy we investigated their propensity for cyclometalation via thermal C-H bond activation on aromatic moieties as well as possible isomerization of cis complexes into trans isomers. We support our experimental findings by single crystal X-ray diffraction and quantum-mechanical calculations.|