Meltable Semiconductive Lead-Thiolate Coordination Polymers with Long Alkyl Chains

Meltable organic-inorganic hybrid semiconductors are attractive for their potential for melt-based processing. Although meltable semiconducting metal halide perovskites have been extensively studied, meltable semiconducting coordination polymers (CPs) remain scarce, despite their excellent structural designability and the tunability of their optoelectronic properties. We report a new family of meltable semiconductive Pb(II) benzenethiolate CPs bearing long alkyl chains, formulated as [Pb(SPhOC₆)₂]_n (KGF-34(C6); HSPhOC₆ = 4-hexyloxybenzenethiol). For comparison, we also synthesized the classical analogue [Pb(SC₆)₂]_n (KGF-59(C6); HSC₆ = 1-hexanethiol). Single-crystal X-ray diffraction analyses revealed that both KGF-34(C6) and KGF-59(C6) adopt 2D architectures, albeit with distinct inorganic (-Pb-S-)_n networks. A comprehensive characterization of the semiconducting properties, combined with first-principles calculations, revealed that KGF-34(C6) exhibits significantly higher photoconductivity, a narrower band gap, and a larger band dispersion than KGF-59(C6), attributable to differences in their inorganic (-Pb-S-)_n network structures. Furthermore, both KGF-34(C6) and KGF-59(C6) exhibit multiple phase transitions, including melting and liquid crystalline formation, enabling the fabrication of optoelectronic devices via melt processing. Notably, this is the first report of meltable semiconducting CPs comprising benzenethiol-derived ligands. These findings offer a rational design strategy for developing melt-processable semiconductive materials based on metal-benzenethiolate CPs.