CuBi₇I₁₉(C₄H₈O₃H)₃(C₄H₈O₃H₂), a Novel Complex Bismuth Iodide Containing One-Dimensional [CuBi₅I₁₉]^3- Chains

CuBi7I19(C4H8O3H)3(C4H8O3H2), a Novel Complex Bismuth Iodide Containing One-Dimensional [CuBi5I19]3- Chain

Bromine-rich Zinc Bromides: Zn₆Br₁₂(18-crown-6)₂×(Br₂)₅, Zn₄Br₈(18-crown-6)₂×(Br₂)₃, and Zn₆Br₁₂(18-crown-6)₂×(Br₂)₂

The bromine-rich zinc bromides Zn6Br12(18-crown-6)2×(Br2)5 (1), Zn4Br8(18-crown-6)2×(Br2)3 (2), and Zn6Br12(18-crown-6)2×(Br2)2 (3) are prepared by reaction of ZnBr2, 18-crown-6, and elemental bromine in the ionic liquid [MeBu3N]­[N­(Tf)2] (N­(Tf)2 = bis­(trifluoromethylsulfonyl)­amide). Zn6Br12(18-crown-6)2×(Br2)5 (1) is formed instantaneously by the reaction. Even at room temperature, compound 1 releases bromine, which was confirmed by thermogravimetry (TG) and mass spectrometry (MS). The release of Br2 can also be directly followed by the color and density of the title compounds. With controlled conditions (2 weeks, 25 °C, absence of excess Br2) Zn6Br12(18-crown-6)2×(Br2)5 (1) slowly releases bromine with conconcurrent generation of Zn4Br8(18-crown-6)2×(Br2)3 (2) (in ionic liquid) and Zn6Br12(18-crown-6)2×(Br2)2 (3) (in inert oil). All bromine-rich zinc bromides contain voluminous uncharged (e.g., Zn3Br6(18-crown-6), Zn2Br4(18-crown-6)) or ionic (e.g., [Zn2Br3(18-crown-6)]+, [(Zn2Br6)×(Br2)2]2–) building units with dibromine molecules between the Zn oligomers and partially interconnecting the Zn-containing building units. Due to the structural similarity, the bromine release is possible via crystal-to-crystal transformation with retention of the crystal shape

One-Pot Synthesis of In⁰ Nanoparticles with Tuned Particle Size and High Oxidation Stability

In0 nanoparticles with tunable size are obtained via NaBH4-induced reduction of InCl3·4H2O in diethylene glycol. Citrate-capping allows nucleating almost monodisperse and non-agglomerated In0 nanoparticles. Effective size tuning is possible in a wide range (10–100 nm) just by varying the concentration of NaBH4, resulting in mean diameters of 8, 55, and 105 nm. The citrate-capped In0 nanoparticles, moreover, turn out as surprisingly stable against air oxidation. According to XRD and SEM analysis, the 8 nm-sized In0 particles are molten at room temperature. Size-dependent evolution of the plasmon resonance is observed and results in a brownish-red color and a distinct absorption in the case of the smallest In0 particles

Bromine-rich Zinc Bromides: Zn₆Br₁₂(18-crown-6)₂×(Br₂)₅, Zn₄Br₈(18-crown-6)₂×(Br₂)₃, and Zn₆Br₁₂(18-crown-6)₂×(Br₂)₂

The bromine-rich zinc bromides Zn₆Br₁₂(18-crown-6)₂×(Br₂)₅ (<b>1</b>), Zn₄Br₈(18-crown-6)₂×(Br₂)₃ (<b>2</b>), and Zn₆Br₁₂(18-crown-6)₂×(Br₂)₂ (<b>3</b>) are prepared by reaction of ZnBr₂, 18-crown-6, and elemental bromine in the ionic liquid [MeBu₃N]­[N­(Tf)₂] (N­(Tf)₂ = bis­(trifluoromethylsulfonyl)­amide). Zn₆Br₁₂(18-crown-6)₂×(Br₂)₅ (<b>1</b>) is formed instantaneously by the reaction. Even at room temperature, compound <b>1</b> releases bromine, which was confirmed by thermogravimetry (TG) and mass spectrometry (MS). The release of Br₂ can also be directly followed by the color and density of the title compounds. With controlled conditions (2 weeks, 25 °C, absence of excess Br₂) Zn₆Br₁₂(18-crown-6)₂×(Br₂)₅ (<b>1</b>) slowly releases bromine with conconcurrent generation of Zn₄Br₈(18-crown-6)₂×(Br₂)₃ (<b>2</b>) (in ionic liquid) and Zn₆Br₁₂(18-crown-6)₂×(Br₂)₂ (<b>3</b>) (in inert oil). All bromine-rich zinc bromides contain voluminous uncharged (e.g., Zn₃Br₆(18-crown-6), Zn₂Br₄(18-crown-6)) or ionic (e.g., [Zn₂Br₃(18-crown-6)]⁺, [(Zn₂Br₆)×(Br₂)₂]^2–) building units with dibromine molecules between the Zn oligomers and partially interconnecting the Zn-containing building units. Due to the structural similarity, the bromine release is possible via crystal-to-crystal transformation with retention of the crystal shape

Insights of the Structure and Luminescence of Mn²⁺/Sn²⁺-Containing Crown-Ether Coordination Compounds

Crown-ether coordination compounds with Mn2+ and Sn2+ as cations and 12-crown-4, 15-crown-5, and 18-crown-6 as ligands are synthesized. Their luminescence properties and quantum yields are compared and correlated with their structural features. Thus, MnI2­(15-crown-5) (1), MnCl2­(15-crown-5) (2), [Mn­(12-crown-4)2]2­[N­(Tf)2]2­(12-crown-4) (3), Sn3I6­(15-crown-5)2 (4), and SnI2­(18-crown-6) (5) are obtained by an ionic-liquid-based reaction of MX2 (M: Mn, Sn; X: Cl, I) and the respective crown ether. Whereas 1, 2, and 5 exhibit a centric coordination of Mn2+/Sn2+ by the crown ether, 3 and 4 show a sandwich-like coordination of the cation with two crown-ether molecules. All title compounds show visible emission, whereof 1, 2, and 5 have good luminescence efficiencies with quantum yields of 47, 39, and 21%, respectively. These luminescence properties are compared with recently realized compounds such as Mn3Cl6­(18-crown-6)2, MnI2­(18-crown-6), Mn3I6­(18-crown-6)2, or Mn2I4­(18-crown-6), which have significantly higher quantum yields of 98 and 100%. Based on a comparison of altogether nine crown-ether coordination compounds, the structural features can be correlated with the luminescence efficiency, which allows extraction of those conditions encouraging intense emission and high quantum yields

Nanoscale γ-AlO(OH) Hollow Spheres: Synthesis and Container-Type Functionality

AlO(OH) hollow spheres are realized via a water-in-oil (w/o) microemulsion, applying the liquid-to-liquid-phase boundary of the micellar system as a template. Scanning electron microscopy, transmission electron microscopy (TEM), and dynamic light scattering analyses show the presence of nonagglomerated hollow spheres exhibiting an outer diameter of about 30 nm and a wall thickness of 5−6 nm. High-resolution TEM images show highly ordered lattice fringes, indicating the crystallinity of the sphere wall and identifying the wall to consist of γ-AlO(OH) (boehmite). The container functionality of as-prepared AlO(OH) hollow spheres is validated as a proof of concept by encapsulating the fluorescent dye rhodamine (R6G) inside the alumina shell. Subsequent to centrifugation and careful purification, R6G is evidenced via photoluminescence to be still present. Finally, release of R6G is initiated by acidic dissolution of the sphere wall

[(Ph)₃PBr][Br₇], [(Bz)(Ph)₃P]₂[Br₈], [(<i>n</i>-Bu)₃MeN]₂[Br₂₀], [C₄MPyr]₂[Br₂₀], and [(Ph)₃PCl]₂[Cl₂I₁₄]: Extending the Horizon of Polyhalides via Synthesis in Ionic Liquids

The five polyhalides [(Ph)3PBr][Br7], [(Bz)(Ph)3P]2[Br8], [(n-Bu)3MeN]2[Br20], [C4MPyr]2[Br20] ([C4MPyr] = N-butyl-N-methylpyrrolidinium), and [(Ph)3PCl]2[Cl2I14] were prepared by the reaction of dibromine and iodine monochloride in ionic liquids. The compounds [(Ph)3PBr][Br7] and [(Bz)(Ph)3P]2[Br8] contain discrete pyramidal [Br7]− and Z-shaped [Br8]2– polybromide anions. [(n-Bu)3MeN]2[Br20] and [C4MPyr]2[Br20] exhibit new infinite two- and three-dimensional polybromide networks and contain the highest percentage of dibromine ever observed in a compound. [(Ph)3PCl]2[Cl2I14] also consists of a three-dimensional network and is the first example of an infinite polyiodine chloride. All compounds were obtained from ionic liquids as the solvent that, on the one hand, guarantees for a high stability against strongly oxidizing Br2 and ICl and that, on the other hand, reduces the high volatility of the molecular halogens

[(Ph)₃PBr][Br₇], [(Bz)(Ph)₃P]₂[Br₈], [(<i>n</i>-Bu)₃MeN]₂[Br₂₀], [C₄MPyr]₂[Br₂₀], and [(Ph)₃PCl]₂[Cl₂I₁₄]: Extending the Horizon of Polyhalides via Synthesis in Ionic Liquids

The five polyhalides [(Ph)₃PBr][Br₇], [(Bz)(Ph)₃P]₂[Br₈], [(<i>n</i>-Bu)₃MeN]₂[Br₂₀], [C₄MPyr]₂[Br₂₀] ([C₄MPyr] = <i>N</i>-butyl-<i>N</i>-methylpyrrolidinium), and [(Ph)₃PCl]₂[Cl₂I₁₄] were prepared by the reaction of dibromine and iodine monochloride in ionic liquids. The compounds [(Ph)₃PBr][Br₇] and [(Bz)(Ph)₃P]₂[Br₈] contain discrete pyramidal [Br₇]⁻ and Z-shaped [Br₈]^2– polybromide anions. [(<i>n</i>-Bu)₃MeN]₂[Br₂₀] and [C₄MPyr]₂[Br₂₀] exhibit new infinite two- and three-dimensional polybromide networks and contain the highest percentage of dibromine ever observed in a compound. [(Ph)₃PCl]₂[Cl₂I₁₄] also consists of a three-dimensional network and is the first example of an infinite polyiodine chloride. All compounds were obtained from ionic liquids as the solvent that, on the one hand, guarantees for a high stability against strongly oxidizing Br₂ and ICl and that, on the other hand, reduces the high volatility of the molecular halogens

Photochemical Synthesis of Particulate Main-Group Elements and Compounds

Particulate main-group elements (As⁰, Sb⁰, Bi⁰, Pb⁰, Se⁰, Te⁰) and compounds (Bi₄Te₃, Sb_<i>x</i>Bi_1–<i>x</i> with 0 ≤ <i>x</i> ≤ 1) are obtained via photoinitiated reduction under UV irradiation. The synthesis of Bi⁰ and Se⁰ is exemplarily studied in detail. Here, meso- to micrometer-scaled particles are obtained with mean diameters of 81(11) nm (Bi⁰) and 1.15(18) μm (Se⁰) in the absence of specific stabilizers that allow controlling the particle growth. In contrast, the particle diameter is significantly reduced in the presence of specific stabilizers (e.g., polyvinylpyrrolidone/PVP for Bi⁰, 2-mercaptoacetid acid/MAA for Se⁰). Now, even the nanoregime is reached with mean diameters of 4(2) nm (Bi⁰) and 290(39) nm (Se⁰). The photochemical synthesis is easy to perform (i.e., aqueous solution/suspension, room temperature, conventional chlorides/oxides as starting materials) and leads to a homogeneous particle nucleation, only initiated by UV irradiation as an external physical trigger. The resulting particulate main group elements and compounds are characterized by electron microscopy (SEM), dynamic light scattering (DLS), X-ray powder diffraction (XRD), and energy-dispersive X-ray (EDX) analysis. The mechanism of the light-initiated reaction can be clarified by polymerization experiments to involve radicals as intermediate species

Sn₃I₈·2(18-crown-6): a Mixed-Valent Tin-Crown-Ether Complex

By reaction of SnI2, SnI4, and crown ether (18-crown-6) in the ionic liquid [NMe(n-Bu)3][N(Tf)2], Sn3I8·2(18-crown-6) is obtained in the form of black, plate-shaped crystals and crystallizes with a monoclinic lattice symmetry. In detail, Sn3I8·2(18-crown-6) is constituted of trigonal-bipyramidal [SnI5]−-anions and [Sn2I3(18-crown-6)2]+-cations. The cation exhibits an endocyclical coordination of Sn2+ by the crown ether. Both constituents are linked via long-ranging I−I contacts to form an infinite network. Besides crystal structure analysis, the mixed valence state of tin is evidenced by 119Sn-Mössbauer spectroscopy