Poly(4-vinylpyridine) as ligand for Au(I) and Zn(II) cations: luminescent metal-containing polymers

Abstract

The poly-dentate ligand poly(4-vinylpyridine) (P4VP, Mw ≈ 60,000 g mol−1) reacts with (Me2S)AuCl or ZnCl2 yielding white polymers with empirical formula (PVP)(AuCl)0.4 and (PVP)(ZnCl2)0.7. Upon excitation with UV light, both metal-containing materials feature luminescence. Emissions of (P4VP)–AuCl are based on aurophilic interactions whereas for (P4VP)–ZnCl2, an excitation wavelength-dependent luminescence could be observed. The latter behavior can be explained by the formation of aggregated species with different excitation energies. For comparison, the model compound (Etpy)AuCl (Etpy = 4-ethylpyridine) is prepared and structurally characterized. The solid-state structure reveals that no aurophilic or π–π interactions are present. The compound does not show photoluminescence. The solid-state structure of the disproportionation product (Etpy)AuCl3 has been determined as well. Graphical abstract.