A curious interplay in the films of N heterocyclic carbene PtII complexes upon deposition of alkali metals
The recently synthesized series of PtII complexes containing cyclometallating (phenylpyridine or benzoquinoline) and N heterocyclic carbene ligands possess intriguing structures, topologies, and light emitting properties. Here, we report curious physicochemical interactions between in situ PVD grown films of a typical representative of the aforementioned PtII complex compounds and Li, Na, K and Cs atoms. Based on a combination of detailed core level photoelectron spectroscopy and quantum chemical calculations at the density functional theory level, we found that the deposition of alkali atoms onto the molecular film leads to unusual redistribution of electron density: essential modification of nitrogen sites, reduction of the coordination PtII centre to Pt0 and decrease of electron density on the bromine atoms. A possible explanation for this is formation of a supramolecular system "Pt complex alkali metal ion" the latter is supported by restoration of the system to the initial state upon subsequent oxygen treatment. The discovered properties highlight a considerable potential of the PtII complexes for a variety of biomedical, sensing, chemical, and electronic applications.
Scientific reports