Synthesis, Crystal Structure, and Optoelectronic Properties of [(n‐/ t ert ‐C ₄ H ₉ )S(CH ₃ ) ₂ ]PbI ₃

We report on the novel, organic–inorganic lead halides [n‐C 4 H 9 S(CH 3 ) 2 ]PbI 3 ( 1‐Pb ) and [ tert ‐C 4 H 9 S(CH 3 ) 2 ]PbI 3 ( 2‐Pb ). The air‐stable compounds were prepared via the 1:1 stoichiometric reaction of n‐butyl‐dimethyl‐sulfonium iodide ( 1 ) or tert ‐butyl‐dimethyl‐sulfonium iodide ( 2 ) with PbI 2 , respectively, either in the solid state or in solution. The crystal structures were determined by single‐crystal X‐ray diffraction at 100 K for 1 (space group P 2 1 /c, No. 14), at 100 and 297 K for 1‐Pb (space group P 2 1 /c, No. 14) and at 297 K for 2‐Pb (space group P bca, No. 61). Both 1‐Pb and 2‐Pb form a 1D network of face‐sharing [PbI 6 ] 4‐ octahedra and isolated sulfonium cations between the inorganic chains. The vibrational modes of all compounds were investigated via Raman and infrared spectroscopy. UV–vis absorption spectroscopy shows an energy bandgap of 3.5 eV for both hybrid materials as well as an excitonic peak at ca. 3.17 eV. Photoluminescence spectroscopy shows a broad emission band with a maximum at ca. 465 nm and a weak excitonic signal at ca. 387 nm. Electron band structure and density‐of‐states calculations were performed to elucidate the experimental optoelectronic properties of the hybrid compounds, pointing to a direct bandgap at the Γ point.