Effects of Compression on the Iodine Local Environment in Dipotassium Zinc Tetraiodate(V) Dihydrate K2Zn(IO3)4·2H2O
[EN] Combining X-ray diffraction with density-functional theory and electron topology calculations, we found that pressure substantially modifies the bonding in K2Zn(IO3)42H2O. We discovered that under compression, there is a progressive change from primary covalent I-O bonds and secondary halogen I...
| Autores: | ; ; ; ; ; ; ; ; ; ; |
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| Tipo de documento: | Artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Lenguaje: | Inglés |
| OAI Identifier: | oai:dnet:riunet______::cf953561371dc675c83ddee3a654589a |
| Acceso en línea: | https://riunet.upv.es/handle/10251/233996 |
| Nivel de acceso: | Acceso abierto |
| Palabra clave: | High-pressure crystallography Iodates Multicenter bonding Iodine hypercoordination Electron topology Band gap |
| Sumario: | [EN] Combining X-ray diffraction with density-functional theory and electron topology calculations, we found that pressure substantially modifies the bonding in K2Zn(IO3)42H2O. We discovered that under compression, there is a progressive change from primary covalent I-O bonds and secondary halogen IO interactions toward O-I-O electron-deficient multicenter bonds. Because of this, iodine hypercoordination converts IO3 trigonal pyramids toward IO6 units. The formation of these IO6 units breaks the typical isolation of iodate molecules, forming an infinite two-dimensional iodate network. Hypercoordination influences the hydrogen atoms too, such that multicenter O-H-O bonds are also promoted with increasing pressure. We have determined that K2Zn(IO3)42H2O is one of the most compressible iodates studied to date, with a bulk modulus of 22(3) GPa. The pressure-induced structural changes strongly modify the electronic structure as shown by optical-absorption measurements and band-structure calculations. The band gap energy closes from 4.2(1) eV at ambient pressure to 3.4(1) eV at 20 GPa. |
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