Heteroatom Effect on Site-Selective Oxygen-Sulfur Substitution Reactions of Keggin-Type Polyoxotungstates.

Inorg Chem

Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8656, Japan.

Published: December 2024

Sulfur, a group 16 element, can substitute the oxygen sites of metal oxides, potentially providing them with unique properties and enabling new applications. Polyoxometalates (POMs) are anionic metal oxide clusters with wide structural diversity owing to arbitrary selection of their constituting metal atoms. However, substitution of the oxygen sites of POMs with sulfur atoms has been rarely explored. Recently, we reacted a Keggin-type POM [XWO] (; X = Si and Ge) with a sulfurizing reagent (Lawesson's reagent), synthesizing Keggin-type polyoxothiometalates (POTMs) [XWOS] (, X = Si and Ge) in which all 12 terminal oxygen atoms of were site-selectively substituted with sulfur atoms. Although the selected heteroatoms (X) and anion charges substantially influence the properties and reactivities of POMs, oxygen-sulfur substitution of Keggin-type POMs with other heteroatoms and anion charges has not been attempted. Herein, we report the oxygen-sulfur substitution reaction of Keggin-type POMs [XWO] (; X = Al, Si, and P; = 5, 4, and 3, respectively) with various heteroatoms, yielding the corresponding Keggin-type POTMs [XWOS] (). The oxygen-sulfur substitution reaction depended on the heteroatom: POMs with higher anion charges reacted more strongly with the sulfurizing reagents. We also investigated the reaction mechanism of POMs and sulfurizing reagents.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.inorgchem.4c04149DOI Listing

Publication Analysis

Top Keywords

oxygen-sulfur substitution
16
anion charges
12
oxygen sites
8
sulfur atoms
8
potms [xwos]
8
heteroatoms anion
8
keggin-type poms
8
substitution reaction
8
sulfurizing reagents
8
poms
7

Similar Publications

Sulfur, a group 16 element, can substitute the oxygen sites of metal oxides, potentially providing them with unique properties and enabling new applications. Polyoxometalates (POMs) are anionic metal oxide clusters with wide structural diversity owing to arbitrary selection of their constituting metal atoms. However, substitution of the oxygen sites of POMs with sulfur atoms has been rarely explored.

View Article and Find Full Text PDF

2-Chloro-1-(1-ethoxyvinyl)pyridinium triflate and several other bench-stable -(1-alkoxyvinyl) 2-halopyridinium triflates have been developed as reagents for the synthesis of valuable 2-aminopyridine scaffolds via unusually mild SAr substitutions with amine nucleophiles. Advantages of this approach include an operationally simple mix-and-stir procedure at room temperature or mild heat and ambient atmosphere and without the need for transition metal catalysts, coupling reagents, or high-boiling solvents. The stable -(1-ethoxyvinyl) moiety serves as a dual SAr-activating group and pyridine -protecting group that can be cleaved under thermal, acidic, or oxidative conditions.

View Article and Find Full Text PDF

Polyoxometalates (POMs) function as platforms for synthesizing structurally well-defined inorganic molecules with diverse structures, metals, compositions, and arrangements. Although post-editing of the oxygen sites of POMs has great potential for development of unprecedented structures, electronic states, properties, and applications, facile methods for site-selective substitution of the oxygen sites with other atoms remain limited. Herein, we report a direct site-selective oxygen-sulfur substitution method that enables transforming POMs [XWO] (X = Si, Ge) to Keggin-type polyoxothiometalates (POTMs) [XWOS] using sulfurizing reagents in an organic solvent.

View Article and Find Full Text PDF

Copper ores and concentrates thereof feature an increasingly notable content of impurities such as arsenic and other hazardous elements. As an alternative to the state-of-the-art partial roasting process, arsenic could be removed by the alkaline sulfide leaching of the copper concentrates. In order to optimize and understand the processes, knowledge of the speciation and oxidation states is essential.

View Article and Find Full Text PDF

Tris(hetaryl)substituted phosphines and their chalcogenides are promising polydentate ligands for the design of metal complexes. An experimental and theoretical conformational analysis of tris[2-(4-pyridyl)ethyl]phosphine, tris[2-(2-pyridyl)ethyl]phosphine, and their chalcogenides was carried out by the methods of dipole moments, IR spectroscopy and DFT B3PW91/6-311++G(df,p) calculations. In solution, these compounds exist as an equilibrium of mainly non-eclipsed (synclinal or antiperiplanar) forms with a predominance of a symmetrical conformer having a -orientation of the C-C bonds of pyridylethyl substituents relative to the P=X bond (X = lone pair, O, S, Se) and a -orientation of the pyridyl rings relative to the zigzag ethylene bridges.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!