{"title":"Synthesis of Hollowed Polyoxometalate with a Flipped VO5 Unit by the Elimination of a Centered Organic Molecule","authors":"Yuji Kikukawa, Mayumi Taga, Yusuke Horikawa, Ryoji Mitsuhashi, Yoshihito Hayashi","doi":"10.1021/acs.inorgchem.4c04682","DOIUrl":null,"url":null,"abstract":"Mechanistic understanding of the formation of clusters plays a role in designing the structure-dependent properties. Based on the fact that anions act as templates to form spherical polyoxovanadates, various structures were reported by changing anions in the synthetic solution. In this work, another factor in the formation of spherical polyoxometalates was demonstrated. By the reaction of [V<sub>10</sub>O<sub>26</sub>]<sup>4–</sup> in acetonitrile with a reductant to increase the number of tetravalent V<sup>4+</sup> and <i>p</i>-toluene sulfonic acid to convert tetrahedral VO<sub>4</sub> units to square-pyramidal VO<sub>5</sub>, acetonitrile-containing polyoxovanadate [V<sub>24</sub>O<sub>60</sub>(CH<sub>3</sub>CN)]<sup>6–</sup> (<b>I</b><sup><b>CH3CN</b></sup>) was synthesized. The bulky and hydrophobic aromatic rings prevented the formed anions from acting as a template. By changing the synthetic solvent, encapsulated moieties were controlled. Nitromethane was also encapsulated to afford [V<sub>24</sub>O<sub>60</sub>(CH<sub>3</sub>NO<sub>2</sub>)]<sup>6–</sup> (<b>I</b><sup><b>CH3NO2</b></sup>). When acetone was used as the solvent, the contaminated water was encapsulated to form [V<sub>24</sub>O<sub>60</sub>(H<sub>2</sub>O)]<sup>6–</sup> (<b>I</b><sup><b>H2O</b></sup>). The encapsulated acetonitrile molecule was eliminated by heating <b>I</b><sup><b>CH3CN</b></sup> up to 230 °C under N<sub>2</sub> flow conditions to give hollowed polyoxovanadate [V<sub>24</sub>O<sub>60</sub>]<sup>6–</sup> (<b>II</b>), even though <b>I</b><sup><b>CH3CN</b></sup> possesses no pores for acetonitrile to pass. From the X-ray crystallographic analysis of <b>II</b>, one of the 24 VO<sub>5</sub> units was flipped. The electrochemical properties and catalytic performances between <b>I</b><sup><b>CH3CN</b></sup> and <b>II</b> were also investigated.","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":"29 1","pages":""},"PeriodicalIF":4.3000,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Inorganic Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1021/acs.inorgchem.4c04682","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
引用次数: 0
Abstract
Mechanistic understanding of the formation of clusters plays a role in designing the structure-dependent properties. Based on the fact that anions act as templates to form spherical polyoxovanadates, various structures were reported by changing anions in the synthetic solution. In this work, another factor in the formation of spherical polyoxometalates was demonstrated. By the reaction of [V10O26]4– in acetonitrile with a reductant to increase the number of tetravalent V4+ and p-toluene sulfonic acid to convert tetrahedral VO4 units to square-pyramidal VO5, acetonitrile-containing polyoxovanadate [V24O60(CH3CN)]6– (ICH3CN) was synthesized. The bulky and hydrophobic aromatic rings prevented the formed anions from acting as a template. By changing the synthetic solvent, encapsulated moieties were controlled. Nitromethane was also encapsulated to afford [V24O60(CH3NO2)]6– (ICH3NO2). When acetone was used as the solvent, the contaminated water was encapsulated to form [V24O60(H2O)]6– (IH2O). The encapsulated acetonitrile molecule was eliminated by heating ICH3CN up to 230 °C under N2 flow conditions to give hollowed polyoxovanadate [V24O60]6– (II), even though ICH3CN possesses no pores for acetonitrile to pass. From the X-ray crystallographic analysis of II, one of the 24 VO5 units was flipped. The electrochemical properties and catalytic performances between ICH3CN and II were also investigated.
期刊介绍:
Inorganic Chemistry publishes fundamental studies in all phases of inorganic chemistry. Coverage includes experimental and theoretical reports on quantitative studies of structure and thermodynamics, kinetics, mechanisms of inorganic reactions, bioinorganic chemistry, and relevant aspects of organometallic chemistry, solid-state phenomena, and chemical bonding theory. Emphasis is placed on the synthesis, structure, thermodynamics, reactivity, spectroscopy, and bonding properties of significant new and known compounds.