Synthesis, Crystal, and Electronic Structure of (HpipeH2)2[Sb2I10](I2), with I2 Molecules Linking Sb2X10 Dimers into a Polymeric Anion: A Strategy for Optimizing a Hybrid Compound’s Band Gap

• Published in: International journal of molecular sciences Vol. 24; no. 3; p. 2201
• Main Authors: Bykov, Andrey V., Shestimerova, Tatiana A., Bykov, Mikhail A., Osminkina, Liubov A., Kuznetsov, Alexey N., Gontcharenko, Victoria E., Shevelkov, Andrei V.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 22-01-2023; MDPI
• Subjects: antimony; Cations; Covalent bonds; Crystal structure; Efficiency; Electronic structure; halometallates; hybrid organic–inorganic compounds; Hydrogen bonds; Iodine; Lead free; Light; polyiodides; Structural analysis; supramolecular ensemble
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms24032201

In searching for a tool for optimizing the band gap of a hybrid compound capable of serving as a light-harvesting material in lead-free photovoltaics, we synthesized a new polyiodoantimonate (HpipeH2)2[Sb2I10](I2) and analyzed its crystal and electronic structure by application of X-ray crystal structure analysis, Raman and diffuse reflectance spectroscopies, and quantum chemical calculations. It was demonstrated that I2 molecules link Sb2I10 edge-sharing octahedra into zig-zag chains, whereas the organic cations link inorganic anionic chains into a 3D structure featuring a complex pattern of covalent bonds and non-covalent interactions. Overall, these features provide the background for forming the electronic structure with a narrow band gap of 1.41 eV, therefore being a versatile tool for optimizing the band gap of a potential light-harvesting hybrid compound.