Solvent-free room-temperature synthesis of brightly luminescent [BMPyr]2_2[SnCl4_4]

The pseudo-ternary tin(II) halide [BMPyr]$_2$[SnCl$_4$] can be obtained just by mixing the starting materials [BMPyr]Cl and SnCl$_2$ at room temperature without additional solvents. The compound shows bright Sn(II)-based emission of deep-red light (λ$_{max}$: 740 nm) with a quantum yield of 88 ± 3% after optimised synthesis. Characterization is performed by X-ray structure analysis, infrared and fluorescence spectroscopy. Exemplary fluorescent thinfilms are realized by solvent processing

Structures and Properties of the Halogenido Stannates(II) [BMIm][Sn3_{3}3Cl7_{7}] and [BMIm][Sn4_{4}Br9_{9}]

The halogenido stannates(II) [BMIm][Sn$_{3}$Cl$_{7}$] and [BMIm][Sn$_{4}$4Br$_{9}$] are obtained by ionic-liquid-based synthesis with SnX$_{2}$ and [BMIm]X (X=Cl, Br; [BMIm]=1-butyl-3-methylimidazolium) near room temperature (45–50 °C). Both form colorless, moisture-sensitive crystals and exhibit layered anionic networks. [BMIm][Sn$_{3}$3Cl$_{7}$7] contains “horseshoe”-like $_{∞}$$^{1}$(SnCl$_{171}$Cl$_{2/2}$) chains that are linked via [SnCl$_{3}$]− anions to $_{∞}$$^{2}$[Sn$_{3}$Cl$_{7}$]− zigzag-planes. [BMIm][Sn$_{4}$Br$_{9}$] contains a complex $_{∞}$$^{2}$[Sn$_{4}$Br$_{9}$]− network with altogether four different crystallographic Sn$_{2+}$ sites and different coordination. For comparison with these complex halogenido stannates(II), PbCl$_{2}$/PbBr$_{2}$ are reacted with similar conditions, which, however, only results in [BMIm][PbCl$_{3}$] containing $_{∞}$$^{1}$[PbCl$_{3}$]− chains. Beside the crystal structures, the thermal and optical properties are examined and feature certain emission of visible light for all title compounds at room temperature. Whereas the quantum yields of [BMIm][Sn$_{4}$Br$_{9}$9] (3 %) and [BMIm][PbCl$_{3}$] (21 %) are low, [BMIm][Sn$_{3}$Cl$_{7}$] shows surprisingly efficient photoluminescence with a quantum yield of 46 %

Ge−Fe Carbonyl Cluster Compounds: Ionic Liquids‐Based Synthesis, Structures, and Properties

Nine Ge−Fe carbonyl cluster compounds are prepared via ionic liquids‐based synthesis. This includes the novel compounds [EMIm][Fe(CO)$_{3}$I(GeI$_{3}$)], [EHIm][Fe(CO)$_{3}$I(GeI$_{3}$)], [BMIm][GeI$_{2}${Fe(CO)$_{4}$}$_{2}$(μ‐I)][AlCl$_{4}$]$_{2}$, [GeI$_{2}${Fe(CO)$_{4}$}$_{2}$(μ‐I)][Fe(AlBr$_{4}$)$_{3}$], [BMIm]$_{2}$[(FeI$_{2}$)$_{0.75}${Fe(CO)$_{2}$I(GeI$_{3}$)$_{2}$}$_{2}$], and [EHIm][Fe(CO)$_{4}$(GeI$_{2}$)$_{2}$Fe(CO)$_{3}$GeI$_{3}$] as well as the previously reported compounds (Fe(CO)$_{4}$(GeI$_{3}$)$_{2}$, FeI$_{4}${GeI$_{3}$Fe(CO)$_{3}$}$_{2}$, and Ge$_{12}${Fe(CO)$_{3}$}$_{8}$(μ‐I)4 (EMIm: 1‐ethyl‐3‐methylimidazolium, EHIm: 1‐ethylimidazolium, BMIm: 1‐butyl‐3‐methylimidazolium). With this series of compounds, a comparison of synthesis conditions and structural features is possible and, for instance, allows correlating the composition and structure of the respective Ge−Fe carbonyl cluster compounds with the type and acidity of the ionic liquid. With [EMIm][{GeI$_{3}$}$_{2}$Fe(CO)$_{3}$I], moreover, we can exemplarily show the thermal decomposition as a single‐source precursor in the ionic liquid, resulting in bimetallic Ge−Fe nanoparticles with small size and narrow size distribution (7.0±1.4 nm)

Identification and characterization of FAM124B as a novel component of a CHD7 and CHD8 containing complex

BACKGROUND: Mutations in the chromodomain helicase DNA binding protein 7 gene (CHD7) lead to CHARGE syndrome, an autosomal dominant multiple malformation disorder. Proteins involved in chromatin remodeling typically act in multiprotein complexes. We previously demonstrated that a part of human CHD7 interacts with a part of human CHD8, another chromodomain helicase DNA binding protein presumably being involved in the pathogenesis of neurodevelopmental (NDD) and autism spectrum disorders (ASD). Because identification of novel CHD7 and CHD8 interacting partners will provide further insights into the pathogenesis of CHARGE syndrome and ASD/NDD, we searched for additional associated polypeptides using the method of stable isotope labeling by amino acids in cell culture (SILAC) in combination with mass spectrometry. PRINCIPLE FINDINGS: The hitherto uncharacterized FAM124B (Family with sequence similarity 124B) was identified as a potential interaction partner of both CHD7 and CHD8. We confirmed the result by co-immunoprecipitation studies and showed a direct binding to the CHD8 part by direct yeast two hybrid experiments. Furthermore, we characterized FAM124B as a mainly nuclear localized protein with a widespread expression in embryonic and adult mouse tissues. CONCLUSION: Our results demonstrate that FAM124B is a potential interacting partner of a CHD7 and CHD8 containing complex. From the overlapping expression pattern between Chd7 and Fam124B at murine embryonic day E12.5 and the high expression of Fam124B in the developing mouse brain, we conclude that Fam124B is a novel protein possibly involved in the pathogenesis of CHARGE syndrome and neurodevelopmental disorders

Phononic filter effect of rattling phonons in the thermoelectric clathrate Ba8_8Ge40+x_{40+x}Ni6−x_{6-x}

One of the key requirements for good thermoelectric materials is a low lattice thermal conductivity. Here we present a combined neutron scattering and theoretical investigation of the lattice dynamics in the type I clathrate system Ba-Ge-Ni, which fulfills this requirement. We observe a strong hybridization between phonons of the Ba guest atoms and acoustic phonons of the Ge-Ni host structure over a wide region of the Brillouin zone which is in contrast with the frequently adopted picture of isolated Ba atoms in Ge-Ni host cages. It occurs without a strong decrease of the acoustic phonon lifetime which contradicts the usual assumption of strong anharmonic phonon--phonon scattering processes. Within the framework of ab-intio density functional theory calculations we interpret these hybridizations as a series of an ti-crossings which act as a low pass filter, preventing the propagation of acoustic phonons. To highlight the effect of such a phononic low pass filter on the thermal transport, we compute the contribution of acoustic phonons to the thermal conductivity of Ba$_8$Ge$_{40}$Ni$_{6}$ and compare it to those of pure Ge and a Ge$_{46}$ empty-cage model system.Comment: 10 pages, 10 figure

Expression in Escherichia coli of a cloned DNA sequence encoding the pre-S2 region of hepatitis B virus

A DNA sequence encoding the entire pre-S2 region (amino acids 120-174; serotype ayw) of human hepatitis B virus envelope protein has been inserted into the lacZ gene of the plasmid pSKS105 yielding a recombinant, pWS3. Lac+ colonies of the Escherichia coli M182 (lacIOPZYA), isolated after transformation with pWS3, produced a pre-S2 peptide-ß-galactosidase fusion protein. This fusion protein, which comprised as much as 3% of the total bacterial protein, was purified to >90% homogeneity by affinity chromatography on p-aminophenyl-ß-D-thiogalactoside-Sepharose. It is immunoprecipitable with rabbit antibodies to a synthetic peptide corresponding to amino acids 120-145 of the pre-S2 region of serotype adw [pre-S(120-145)] or with antibodies to hepatitis B virus. pre-S(120-145) completely blocked the binding of either antibody to the pre-S2 peptide-ß-galactosidase fusion protein. These results indicate that there are antigenic determinants on the fusion protein that are closely related to, if not identical to, determinants on synthetic pre-S(120-145) and on pre-S2 sequences of native hepatitis B virus particles. Thus, bacteria transformed with pWS3 can provide an abundant source of pre-S2-ß-galactosidase fusion protein, which may prove useful either as a diagnostic reagent possessing marker enzyme activity suitable for ELISA tests or as an immunogen with potential to contribute to active prophylaxis of hepatitis B