Investigations on Tetragonally Distorted Sodium Thallide NaTl-tI8

In-depth investigations of the long-time known Zintl phase NaTl revealed a phase transition of tetragonal NaTl-tI8 [I4₁/amd; a = 5.2268(9) Å, c = 7.539(1) Å, V = 205.97(9) ų] to Zintl's cubic NaTl-cF16 [Fd3 m; a = 7.4697(6) Å, V = 416.79(5) ų] between 351 and 355 K. This phase transformation was observed for NaTl prepared by two different synthetic routes including Zintl's original procedure. An excess of sodium applied during the synthesis in liquid ammonia also resulted in the formation of NaTl-tI8. DSC measurements suggest a first order phase transition. In addition to in-situ temperature dependent powder X-ray diffraction experiments, DSC measurements and solid-state NMR investigations, we also performed theoretical DOS and band structure calculations for the cubic and tetragonal phase, respectively. The results suggest Na-Tl interactions in the second coordination sphere being responsible for the observed tetragonal distortion of Zintl's cubic NaTl.     

Electron Storage Capability and Singlet Oxygen Productivity of a RuII Photosensitizer Containing a Fused Naphthaloylenebenzene Moiety at the 1,10-Phenanthroline Ligand

As a novel rylene type dye a diimine ligand with a fully rigid and extended π-system in its backbone was prepared by directly fusing a 1,10-phenanthroline building block with 1,8-naphthalimide. The corresponding heteroleptic ruthenium photosensitizer bearing one biipo and two tbbpy ligands was synthesized and extensively analyzed by a combination of NMR, single crystal X-ray diffraction, steady-state absorption and emission, time-resolved spectroscopy and different electrochemical measurements supported by time-dependent density functional theory calculations. The cyclic and differential pulse voltammograms revealed, that the naphthaloylenebenzene moiety enables an additional second reduction of the ligand. Moreover, this ligand possesses a very broad absorption in the visible region. In the Ru^II complex this causes an overlap of ligand-centered and metal-to-ligand charge transfer transitions. The emission of the complex is clearly redshifted compared to the ligand emission with very long-lived excited states lifetimes of 1.7 and 24.7 μs in oxygen-free acetonitrile solution. This behavior is accompanied by a surprisingly high oxygen sensitivity. Finally, this photosensitizer was successfully applied for the effective evolution of singlet oxygen challenging some of the common Ru^II prototype complexes.     

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Kings in multipartite hypertournaments

In his paper “Kings in Bipartite Hypertournaments,” Petrovic stated two conjectures on 4-kings in multipartite hypertournaments. We prove one of these conjectures and give counterexamples for the other.     

High-density micro-arrays for mass spectrometry

Functional high-density micro-arrays for mass spectrometry enable rapid picolitre-volume aliquoting and ultrasensitive analysis of microscale samples, for example, single cells.     

Chemical composition and antimicrobial activity of cumin oil (Cuminum cyminum, Apiaceae)

Cumin oil samples (Cuminum cyminum L.) from four different geographical origins were analyzed using GC-MS and GC-FID for their qualitative and quantitative composition. The major compounds in all cumin oils were the monoterpenes beta-pinene, p-cymene and gamma-terpinene and the terpenoid aldehydes cuminic aldehyde and the isomeric menthadien carboxaldehydes. All essential oils, and cuminic aldehyde, were tested, using agar diffusion and serial dilution methods, against different Gram-positive and Gram-negative bacteria isolated from different sources of food (pork fillet, minced meat and sausages) and clinical isolates, as well as three different Candida albicans isolates. All cumin oils and cuminic aldehyde exhibited a considerable inhibitory effect against all the organisms tested, except Pseudomonas spp.     

Chemical composition, olfactory evaluation and antimicrobial activity of selected essential oils and absolutes from Morocco

The chemical compositions of selected essential oils from North Africa, especially Morocco, of geranium, wild Moroccan chamomile and rosemary as well as absolutes of rose and geranium were determined using GC/FID and GC/MS. These oils and absolutes were tested concerning their antimicrobial activity against some food spoilage strains obtained from fresh milk and minced meat products, like sausages and pork fillet, in accordance with ISO testing procedures. Gram-positive (Bacillus cereus and Staphylococcus aureus) and Gram-negative (Escherichia coli, Salmonella abony and Pseudomonas aeruginosa) strains were used, as well as the yeast Candida albicans. Using a serial broth dilution method, all samples demonstrated weak antimicrobial activity against the Gram-negative bacteria and the yeast, compared with the activity towards the Gram-positive bacteria.     

Synthesis and Crystal Structure of a Bixbyite‐Type Solid Solution Zr0.43Er0.57O1.07N0.43

A powder of the composition 40 mol‐% Er₂O₃ and 60 mol‐% ZrO₂ has been prepared. The anion deficient fluorite related compound Zr₃Er₄O₁₂ [R\bar{3} : a = 971.79(7) pm and c = 907.976(0) pm] was produced. This precursor was treated with gaseous ammonia at temperatures between 25 and 1200 °C. The reaction was followed in situ by X‐ray diffraction in a high temperature reaction chamber under a constant flow of ammonia. The nitridation of Zr₃Er₄O₁₂ led to a nitride oxide of the solid‐solution‐type with an apparent composition Zr_0.43Er_0.57O_1.07N_0.43 The compound crystallizes isostructural to bixbyite due to vacancy ordering [Ia\bar{3} : a = 1036.37(4) pm]. The reoxidation of the nitride oxide was monitored in DTA/TG experiments exhibiting an almost complete reoxidation to the starting composition except for some inclusions of dinitrogen.     

Cover Picture: Synthesis and Reactivity of Functionalized Binary and Ternary Thiometallate Complexes [(RT)4S6], [(RSn)3S4]2−, [(RT)2(CuPPh3)6S6], and [(RSn)6(OMe)6Cu2S6]4− (R=C2H4COOH,CMe2CH2COMe; T=Ge,Sn) (Chem. Eur. J. 27/2009)

Proof‐of‐principle is reported for a directed functionalization and derivatization of chalcogenidometallate cages with respect to the formation of hybrid compounds containing (M)/T/E semi‐conductor nodes (M=Cu; T=Ge, Sn; E=S). In their Full Paper on page 6595 ff. , S. Dehnen et al. show how it is possible to generate functionalized ternary CuSnS or CuGeS clusters and to transfer COMe ligands into CR(N–NH₂) or CR(N–NHPh) terminal groups by reaction of a series of novel, functionalized thiometallate cages [(RT)_nS_m] (n/m=4/6, 3/4), the R ligands of which are terminated by COO(H) or COMe.

     

Liquid scintillation detectors for high energy neutrinos

Large liquid scintillation detectors have been generally used for low energy neutrino measurements, in the MeV energy region. We describe the potential employment of large detectors (>1 kiloton) for studies of higher energy neutrino interactions, such as cosmic rays and long baseline experiments. When considering the physics potential of new large instruments the possibility of doing useful measurements with higher energy neutrino interactions has been overlooked. Here we take into account Fermat’s principle, which states that the first light to reach each PMT will follow the shortest path between that PMT and the point of origin. We describe the geometry of this process, and the resulting wavefront, which we call the “Fermat surface”, and discuss methods of using this surface to extract directional track information and particle identification. This capability may be demonstrated in the new long baseline neutrino beam from Jaeri accelerator to the KamLAND detector in Japan. Other exciting applications include the use of Hanohano as a movable long baseline detector in this same beam, and LENA in Europe for future long baseline neutrino beams from CERN. Also, this methodology opens up the question as to whether a large liquid scintillator detector should be given consideration for use in a future long baseline experiment from Fermilab to the DUSEL underground laboratory at Homestake.