Coordination polymers with metal−sulfur (M−S) bonds in their nodes have interesting optical properties and can be used as photocatalysts for water splitting. A wide range of inorganic−organic hybrid materials with M−S bonds have been prepared in recent years. However, there is a dearth of structural information because of their low crystallinity, which has hampered the understanding of their underlying chemistry and physics. Thus, we conducted a structural study of a novel, highly crystalline coordination polymer with M−S bonds. Theoretical calculations were performed to elucidate its photoconductivity mechanism. The photoconductive, three-dimensional coordination polymer [Pb(tadt)] n (denoted as KGF-9; tadt = 1,3,4-thiadiazole-2,5-dithiolate) was synthesized and confirmed to have a three-dimensional structure containing a two-dimensional Pb−S framework by singlecrystal X-ray diffraction. We also performed diffuse-reflectance ultraviolet−visible−near-infrared spectroscopy, time-resolved microwave conductivity, and photoelectron yield spectroscopy measurements on the bulk powder samples, as well as first-principles calculations. Additionally, direct-current photoconductivity measurements were conducted on a single-crystal sample.

Monolayer molybdenum disulfide’s (MoS2) direct band gap nature makes it a good platform for realizing atomically thin optoelectronic devices. However, an issue is its low luminescence brightness. In this research, we demonstrate a strategy to achieve strong photoluminescence (PL) of monolayer MoS2, by treatment with a redox-active molecule, fluoranil. An important finding is that the factor of PL enhancement depends strongly on the solvent used and the PL changes by more than one order of magnitude. This work is useful for harnessing the strong optical properties of MoS2 by the combination of oxidizing molecules and engineering the solvent used.

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Transition metal dichalcogenides (TMDCs) have received attention as atomically thin post‐silicon semiconducting materials. Tuning the carrier concentrations of the TMDCs is important, but their thin structure requires a non‐destructive modulation method. Recently, a surface‐charge transfer doping method was developed based on contacting molecules on TMDCs, and the method succeeded in achieving a large modulation of the electronic structures. The successful dopant is a neutral benzyl viologen (BV 0 ); however, the problem remains of how to effectively prepare the BV 0 molecules. A reduction process with NaBH 4 in water has been proposed as a preparation method, but the NaBH 4 simultaneously reacts vigorously with the water. Here, a simple method is developed, in which the reaction vial is placed on a hotplate and a fragment of air‐stable metal is used instead of NaBH 4 to prepare the BV 0 dopant molecules. The prepared BV 0 molecules show a strong doping ability in terms of achieving a degenerate situation of a TMDC, MoS 2 . A key finding in this preparation method is that a convection flow in the vial effectively transports the produced BV 0 to a collection solvent. This method is simple and safe and facilitates the tuning of the optoelectronic properties of nanomaterials by the easily‐handled dopant molecules.