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)}]n, 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.