On the synthesis and structure of HgSe clusters: Synthetic–structural considerations and optical features of new cluster compounds

• Published in: Polyhedron Vol. 35; no. 1; pp. 137 - 141
• Main Authors: Stieler, Rafael, Bublitz, Fabrício, Schulz Lang, Ernesto, Manzoni de Oliveira, Gelson
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 16.03.2012
• Subjects: Cluster compounds; Mercury-clusters; Single HgSe-clusters; Single HgSe-clusters; Mercury-clusters; Cluster compounds
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2012.01.006

MgCl2·6H2O, MgBr2, MgI2, FeCl2, NiCl2 and {1,3-bis(diphenyl-phosphine)propane} react with Hg(SePh)2 to give the new cluster compounds [M(dmf)6][Hg8SeX4(PhSe)12] {M=Mg2+: X=Cl (1a), Br (1b), I (1c); for M=Fe2+ (2) and Ni2+ (3), X=Cl}. Compound 3 reproduces with selenium an earlier reported tellurium cluster. In the anions [Hg8SeX4(PhSe)12]2− the eight Hg atoms exhibit a distorted square antiprismatic assembly with a four-coordinated μ4-Se atom in the center, performing an ideal tetrahedral arrangement. [Display omitted] ► Synthesis of five single binuclear Hg(SePh) clusters stabilized by octahedral complexes. ► X-ray structural characterization of all compounds. ► Optical features and HOMO–LUMO energy-gaps obtained graphically from UV–Vis absorption spectra. ► Discussion about the non-inclusion of Mg2+, Fe2+ and Ni2+ into the cluster structure. MgCl2·6H2O, MgBr2, MgI2, FeCl2, NiCl2 and dppp {1,3-bis(diphenyl-phosphine)propane} react with Hg(SePh)2 in dimethylformamide (dmf) to give the new cluster compounds [M(dmf)6][Hg8SeX4(PhSe)12] {M=Mg2+: X=Cl (1a), Br (1b), I (1c); for M=Fe2+ (2) and Ni2+ (3), X=Cl}. All the clusters show the presence of [μ-Se] bridges, achieved by all the [SePh]− groups. Compound 3 reproduces with selenium an earlier reported tellurium cluster. In the anions [Hg8SeX4(PhSe)12]2− the eight Hg atoms exhibit a distorted square antiprismatic assembly with a four-coordinated μ4-Se atom in the center, in an ideal tetrahedral arrangement. The counter ions [M(dmf)6]2+ attain perfect octahedral geometries, with the three octahedral axis presenting exactly 180°. The use of intermediary ligands and their synthetical utilities will discussed, as well as some optical features of the title compounds.