Meltable Semiconductive Lead-Thiolate Coordination Polymers with Long Alkyl Chains

Meltable organic–inorganic hybrid semiconductors have attracted considerable research attention owing to their potential for melt-based processing, offering distinct advantages over conventional solution-based techniques. Although meltable semiconducting metal halide perovskites have been extensively studied, meltable semiconducting coordination polymers remain scarce, despite their excellent structural designability and the tunability of their optoelectronic properties. Herein, we report a new family of meltable semiconductive Pb(II) benzenethiolate coordination polymers bearing long alkyl chains, formulated as [Pb(SPhOC6)2]n (KGF-34(C6); HSPhOC6 = 4-hexyloxybenzenethiol, KGF = Kwansei Gakuin Framework). 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 two-dimensional 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, thereby enabling the fabrication of optoelectronic devices via melt processing. Notably, this is the first report of meltable semiconducting coordination polymers comprising benzenethiol-derived ligands. The findings of this study offer a rational design strategy for developing melt-processable semiconductive materials based on metal-benzenethiolate coordination polymers.