Structural Diversity and Multielectron Reduction Reactivity of Samarium(II) Iodido-β-diketiminate Complexes Dependent on Tetrahydrofuran Content

The molecular structures of complexes [Sm(Nacnac)I(thf)n] (Nacnac = HC(C(Me)Ndipp)2–, dipp = 2,6-diisopropylphenyl, thf = tetrahydrofuran) depending on the number of thf ligands are studied. The complete removal of thf from a known complex [Sm(Nacnac)I(thf)2] leads to a tetranuclear product [Sm(Nacnac)I]4 (4). The partial removal of thf results in mixtures of dinuclear [Sm2(Nacnac)2I2(thf)] (2), trinuclear [Sm3(Nacnac)3I3(thf)] (3), and tetranuclear [Sm4(Nacnac)4I4(thf)2] (4*) complexes and 4, depending on the conditions. The reaction of solvent-free SmI2 with 1 equiv of K(Nacnac) results mainly in [Sm(Nacnac)2] (1), while the interaction of 4 with certain amounts of thf allows obtaining pure 2 and 3 (with the admixture of 4*). Complex 4* is the exact dimer of 2, and both compounds are stable in solutions. Reactions with 3 and 4 as reductants are studied. 4 is oxidized by I2 to stoichiometrically yield two products, mixed-valent tetranuclear [Sm4(Nacnac)4I5] (5) and binuclear [Sm(Nacnac)I2]2 (6) complexes. In the reaction of 4 with nBu3PTe, a trinuclear complex [Sm3(Nacnac)3(μ-I)3(μ3-E)2] (8, E = I or Te) is formed in small amounts, with the formation of 6 as the second product. 3 serves as a two-electron reductant in the reaction with nBu3PTe to yield a trinuclear complex [Sm3(Nacnac)3I3(μ-Te2)] (7). Complexes 2, 4, 4*, 5, 6, and 8 possess a unique flat SmxIy core of heavy atoms, which is assumed to be a consequence of the Nacnac ligand geometry

Replenishment in the Family of Rhenium Chalcobromides; Synthesis and Structure of Molecular {Re₄S₄}Br₈(TeBr₂)₄, Dimeric [{Re₄S₄}Br₈(TeBr₂)₃]₂, and Polymeric {Re₄S₄}Br₈ Compounds Based on the {Re₄S₄}⁸⁺ Tetrahedral Cluster Core

We have obtained three new rhenium(IV) chalcobromides belonging to the homologous series {Re4S4}Br8(TeBr2)n (n = 0, 3, 4): a molecular complex {Re4S4}Br8(TeBr2)4 (1), a dimeric complex [{Re4S4}(TeBr2)3Br7(μ-Br)]2 (2), and a two-dimensional (2D) polymeric compound {Re4S4}Br8 (3). Compound 1 is isotypic to the already known {Re4Te4}(TeBr2)4Br8, while 2 and 3 exhibit a new type of binding of tetrahedral clusters via μ-Br bridges. Compounds were characterized by X-ray single-crystal diffraction, X-ray powder diffraction, and thermal and elemental analyses. In compound 2, two tetrahedral cluster cores {Re4S4}8+ are linked together forming a dimer through two Re−μ-Br–Re bridges. Calculations of the electron localization function (ELF) showed that there is no covalent interaction between rhenium atoms of neighboring clusters. In compound 3, each rhenium atom of the {Re4S4}8+ core is coordinated by three Br ligands: one terminal Br and two bridging μ-Br ligands. As a result, eight bridging bromine atoms link {Re4S4}8+ cluster cores into goffered layers. {Re4S4}Br8 is the new stable rhenium(IV) thiobromide, the first discovered in the Re–S–Br system, along with the already known octahedral rhenium(III) thiobromides Re6S4+xBr10–2x (x = 0–4)

Synthesis, Crystal Structure, and Luminescent Properties of Novel Zinc Metal–Organic Frameworks Based on 1,3-Bis(1,2,4-triazol-1-yl)propane

Three new zinc three-dimensional coordination polymers with flexible 1,3-bis­(1,2,4-triazol-1-yl)­propane ligand were synthesized. The crystal structures of synthesized compounds were determined, and structural peculiarities are discussed. Coordination compounds with composition [Zn­(btrp)­(bdc)]·<i>n</i>DMF are interpenetrated frameworks, while metal–organic framework (MOF) [Zn₃(btrp)­(bdc)₃]·<i>n</i>DMF is not. Thermal stability and luminescent properties of synthesized compounds have been investigated. The possibility of usage of such compounds as sensitive materials for some aromatic compounds are explored, and it was shown that luminescence of coordination polymers is completely quenched in the presence of nitrobenzene. Sorption properties of synthesized MOFs toward nitrogen, carbon dioxide, and hydrogen were evaluated