دورية
Selenium as a Structural Surrogate of Sulfur: Template-Assisted Assembly of Five Types of Tungsten–Iron–Sulfur/Selenium Clusters and the Structural Fate of Chalcogenide Reactants
| العنوان: | Selenium as a Structural Surrogate of Sulfur: Template-Assisted Assembly of Five Types of Tungsten–Iron–Sulfur/Selenium Clusters and the Structural Fate of Chalcogenide Reactants |
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| المؤلفون: | Zheng, Bo, Chen, Xu-Dong, Zheng, Shao-Liang, Holm, R. H. |
| المصدر: | Journal of the American Chemical Society; 20240101, Issue: Preprints |
| مستخلص: | Syntheses of five types of tungsten–iron–sulfur/selenium clusters, namely, incomplete cubanes, single cubanes, edge-bridged double cubanes (EBDCs), PN-type clusters, and double-cuboidal clusters, have been devised using the concept of template-assisted assembly. The template reactant is six-coordinate [(Tp*)WVIS3]1–[Tp* = tris(3,5-dimethylpyrazolyl)hydroborate(1−)], which in the assembly systems organizes Fe2+/3+and sulfide/selenide into cuboidal [(Tp*)WFe2S3] or cubane [(Tp*)WFe3S3Q] (Q = S, Se) units. With appropriate terminal iron ligation, these units are capable of independent existence or may be transformed into higher-nuclearity species. Selenide is used as a surrogate for sulfide in cluster assembly in order to determine by X-ray structures the position occupied by an external chalcogenide nucleophile or an internal chalcogenide atom in the product clusters. Specific incorporation of selenide is demonstrated by the formation of [WFe3S3Se]2+/3+cubane cores. Reductive dimerization of the cubane leads to the EBDC core [W2Fe6S6Se2]2+containing μ4-Se sites. Reaction of these species with HSe–affords the PN-type cores [W2Fe6S6Se3]1+, in which selenide occupies μ6-Se and μ2-Se sites. The reaction of [(Tp*)WS3]1–, FeCl2, and Na2Se yields the double-cuboidal [W2Fe4S6Se3]2+/0core with μ2-Se and μ4-Se bridges. It is highly probable that in analogous sulfide-only assembly systems, external and internal sulfide reactants occupy corresponding positions in the cluster products. The results further demonstrate the viability of template-assisted cluster synthesis inasmuch as the reduced (Tp*)WS3unit is present in all of the clusters. Structures, zero-field Mössbauer data, and redox potentials are presented for each cluster type. |
| قاعدة البيانات: | Supplemental Index |
Find this issue from the American Chemical Society | تدمد: | 00027863 15205126 |
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| DOI: | 10.1021/ja3010539 |