Structural and Photophysical Modulation of Au(I)–Pb(II) Chains by Solvent Inclusion: A Study of Solvatopolymorphs

This work presents the synthesis, structural characterization, and photophysical studies of a new gold-(I)-lead-(II) heterometallic polymeric complex, [{Au-(C₆F₅)₂}₂{Pb-(S-Terpy)}] _<i>n</i> , and its solvatopolymorphs incorporating acetone and diethyl ether. The complex exhibits reversible solvatochromic behavior with significant changes in color and luminescence upon solvent inclusion. X-ray diffraction reveals that the trinuclear Au-Pb-Au units are maintained across all solvatopolymorphs, although the packing and intermetallic distances vary depending on the solvent and its coordination mode. Optical studies show that the complexes emit in the visible to near-infrared region, with emission properties strongly influenced by the nature of the solvent. DFT and TD-DFT reveal that the emission arises from metal-to-ligand or ligand-to-ligand charge transfer transitions, depending on the structure. These results highlight the potential of gold-lead supramolecular systems as responsive luminescent materials for sensing applications.