10.1021/ja3010539.s002 Bo Zheng Bo Zheng Xu-Dong Chen Xu-Dong Chen Shao-Liang Zheng Shao-Liang Zheng R. H. Holm R. H. Holm 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 American Chemical Society 2016 W 2Fe EBDC W 2Fe core assembly WFe 3S cubane cores Tp cluster terminal iron ligation Na 2Se yields 2016-02-21 14:53:43 Journal contribution https://acs.figshare.com/articles/journal_contribution/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/2531920 Syntheses of five types of tungsten–iron–sulfur/selenium clusters, namely, incomplete cubanes, single cubanes, edge-bridged double cubanes (EBDCs), P<sup>N</sup>-type clusters, and double-cuboidal clusters, have been devised using the concept of template-assisted assembly. The template reactant is six-coordinate [(Tp*)­W<sup>VI</sup>S<sub>3</sub>]<sup>1–</sup> [Tp* = tris­(3,5-dimethylpyrazolyl)­hydroborate(1−)], which in the assembly systems organizes Fe<sup>2+/3+</sup> and sulfide/selenide into cuboidal [(Tp*)­WFe<sub>2</sub>S<sub>3</sub>] or cubane [(Tp*)­WFe<sub>3</sub>S<sub>3</sub>Q] (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 [WFe<sub>3</sub>S<sub>3</sub>Se]<sup>2+/3+</sup> cubane cores. Reductive dimerization of the cubane leads to the EBDC core [W<sub>2</sub>Fe<sub>6</sub>S<sub>6</sub>Se<sub>2</sub>]<sup>2+</sup> containing μ<sub>4</sub>-Se sites. Reaction of these species with HSe<sup>–</sup> affords the P<sup>N</sup>-type cores [W<sub>2</sub>Fe<sub>6</sub>S<sub>6</sub>Se<sub>3</sub>]<sup>1+</sup>, in which selenide occupies μ<sub>6</sub>-Se and μ<sub>2</sub>-Se sites. The reaction of [(Tp*)­WS<sub>3</sub>]<sup>1–</sup>, FeCl<sub>2</sub>, and Na<sub>2</sub>Se yields the double-cuboidal [W<sub>2</sub>Fe<sub>4</sub>S<sub>6</sub>Se<sub>3</sub>]<sup>2+/0</sup> core with μ<sub>2</sub>-Se and μ<sub>4</sub>-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*)­WS<sub>3</sub> unit is present in all of the clusters. Structures, zero-field Mössbauer data, and redox potentials are presented for each cluster type.