Molecular Thorium Compounds with Dichalcogenide Ligands: Synthesis, Structure, Se NMR Study, and Thermolysis.

A series of dimeric thorium disulfides and diselenides have been prepared with sterically undemanding ancillary ligands. Five complexes, (py)ThI(μ-S), (py)ThBr(SCF)(μ-S), (py)ThI(μ-Se), (py)ThI(SCF)(μ-Se), and (py)ThBr(SCF)(μ-Se), were isolated in high yields by first reducing mixtures of I, FCSSCF, PhSeSePh, or PhSSPh, and PhSeBr with elemental Th, followed by in situ ligand-based redox reactions with elemental sulfur or selenium. These are the first examples of thorium compounds with bridging dichalcogenide ligands.

Organosoluble tetravalent actinide di- and trifluorides.

Soluble molecular actinide(iv) fluorides can be prepared in high yield via redox or metathesis reactions of silver fluorides with actinide compounds containing ancillary iodide or fluorinated thiolate ligands. Two compounds, (py)4UF2I2·2py and (py)7Th2F5(SC6F5)3·2py were isolated and characterized by conventional methods, powder and low temperature single crystal X-ray diffraction.

Monomeric thorium chalcogenolates with bipyridine and terpyridine ligands.

Thorium chalcogenolates Th(ER)4 react with 2,2'-bipyridine (bipy) to form complexes with the stoichiometry (bipy)2Th(ER)4 (E = S, Se; R = Ph, C6F5). All four compounds have been isolated and characterized by spectroscopic methods and low-temperature single crystal X-ray diffraction. Two of the products, (bipy)2Th(SC6F5)4 and (bipy)2Th(SeC6F5)4, crystallize with lattice solvent, (bipy)2Th(SPh)4 crystallizes with no lattice solvent, and the selenolate (bipy)2Th(SePh)4 crystallizes in two phases, with and without lattice solvent.

Thorium Cubanes-Synthesis, Solid-State and Solution Structures, Thermolysis, and Chalcogen Exchange Reactions.

Thorium cubanes (py)Th(μ-E')(μ-EPh)(η-EPh) (E, E' = S, Se) were prepared from ligand-based redox reactions of elemental E' with Th(EPh). Products with all four possible E/E' combinations (E,E' = S,S; Se,Se; S,Se; Se,S) were isolated and structurally characterized, ligand exchange reactions were explored, and the heterochalcogen compounds (py)Th(μ-S)(μ-SePh)(η-SePh) and (py)Th(μ-Se)(μ-SPh)(η-SPh) were heated to deliver solid solutions of ThS Se. NMR spectroscopy indicated that the structure of (py)Th(μ-Se)(μ-SePh)(η-SePh) is static in pyridine solution, with no exchange between bridging and terminal PhE ligands on the NMR time scale.

Efficient NIR Emission from Nd, Er, and Tm Complexes with Fluorinated Selenolate Ligands.

(DME)Ln(SeCF) (Ln = Nd, Er, Tm) can be isolated in high yield by reductive cleavage of the Se-Se bond in (SeCF) with elemental Ln in DME. All three Ln compounds are isostructural, with 8 coordinate Ln bound to four O from DME, three terminally bound Se(CF), and a dative bond from an arene fluoride to a fluorine at the ortho position of one selenolate. Emission measurements indicate that these compounds are bright NIR sources.

Tetrametallic Thorium Compounds with ThE (E = S, Se) Cubane Cores.

Tetrametallic thorium compounds with a ThE core (E = S, Se) having a distorted cubane structure can be prepared by ligand-based reductions of elemental E with thorium chalcogenolates, prepared by in situ oxidation of Th metal with a 3:1 mixture of PhEEPh and FCEECF. Four compounds, (py)ThS(μ-SPh)(SCF), (py)ThS(μ-SPh)(SeCF), (py)ThSe(μ-SePh)(SeCF), and (py)ThSe(μ-SePh)(SCF), were isolated and characterized by NMR spectroscopy and X-ray diffraction. These compounds clearly demonstrate the chemical impact of ring fluorination, with the less-nucleophilic ECF ligands occupying the terminal binding sites and the EPh ligands bridging two metal centers.

Thorium Compounds with Bonds to Sulfur or Selenium: Synthesis, Structure, and Thermolysis.

Thorium chalcogenolates Th(ER)4 (E = S, Se; R = Ph, C6F5) form pyridine complexes with a variety of coordination numbers. Four compounds, (py)4Th(SPh)4, (py)3Th(SePh)4, (py)3Th(SC6F5)4, and (py)4Th(SeC6F5)4, have been isolated and characterized by spectroscopic methods and low-temperature single crystal X-ray diffraction. Two of the products, (py)4Th(SPh)4 and (py)4Th(SeC6F5)4, have classic eight coordinate A4B4 square-antiprism geometries.

Copper, indium, tin, and lead complexes with fluorinated selenolate ligands: precursors to MSex.

Reductive cleavage of C6F5SeSeC6F5 with elemental M (M = Cu, In, Sn, Pb) in pyridine results in the formation of (py)4Cu2(SeC6F5)2, (py)2In(SeC6F5)3, (py)2Sn(SeC6F5)2, and (py)2Pb(SeC6F5)2. Each group adopts a unique structure: the Cu(I) compound crystallizes as a dimer with a pair of bridging selenolates, two pyridine ligands coordinating to each Cu(I) ion, and a short Cu(I)-Cu(I) distance (2.595 Å).