Synthesis,Raman and NMR spectroscopy of the trimetallic complexes [IrCl(SnCl3)(HgCl)(CO)(PR3)2]

Synthesis, Raman and NMR studies are presented for the new octahedral trimetallic complexes with composition [IrCl(SnCl₃)(HgCl)(CO)(PR₃)₂], R = p-XC₆H₄; X = H, CH₃O, F, Cl. Only the isomer containing the Cl₃SnIrHgCl fragment and trans phosphine ligands is observed. Force constants for the IrSn and IrHg bonds as well as ³¹P, ¹¹⁹Sn and ¹⁹⁹Hg NMR data are reported. The presence of a spin-spin coupling constant of more than 40,000 Hz between the ¹⁹⁹Hg and ¹¹⁹Sn atoms is shown to originate from a two-bond and not a one-bond interaction.     

NMR-Untersuchungen an Naturstoffen I.1H-NMR-spektroskopische Konformationsanalyse des Elemols

The preferential conformation of elemol (1 a) is determined by means of lanthanide induced shifts in the¹H-nmr spectrum.

     

Development of a chip-based capillary gel electrophoresis method for quantification of a half-antibody in immunoglobulin G4 samples

A method based on microfluidic technology was developed to support quantitative analysis of recombinant monoclonal immunoglobulin G4 (IgG4) antibody samples. The assay was performed on an Agilent 2100 Bioanalyzer in combination with the Protein 200 Plus LabChip Kit and the Protein 200 Plus assay software. Capillary electrophoresis principles have been transferred to a chip format that integrates all separation, staining, virtual destaining, and detection steps. The method is referred to in this paper as chip-based capillary gel electrophoresis (GelChip-CE method). The GelChip-CE method under nonreducing conditions proved to be a quantitative test for half-antibody determination in IgG4 samples. Similar to the traditional nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method, the GelChip-CE method includes a denaturing step prior to separation. We showed that denaturing the sample by heating resulted in an artificial increase in the amount of half-antibody detected, which could be prevented by addition of N-ethylmaleimide to the sample buffer. The GelChip-CE method allowed for analysis of IgG4 samples with more accuracy, higher precision, and a faster turnaround time than SDS-PAGE and reversed-phase high-performance liquid chromatography (RP-HPLC).     

间位苯基桥联的锰（Ⅲ）双咔咯的合成、表征及催化氧化性质

通过间苯二甲醛与5-氟苯基二吡咯甲烷反应合成了一种新的间位苯基桥联的双咔咯1,并利用锰盐与自由咔咯反应制备了其锰的金属配合物2。采用紫外、质谱、核磁、XPS等手段对化合物进行了表征。以苯乙烯为底物考察了锰双咔咯2的催化氧化性质,探讨了时间、溶剂、氧源、轴向配体对催化反应的影响。结果表明以亚碘酰苯和间氯过氧苯甲酸为氧源时催化的主要产物为环氧苯乙烷,而以双氧水和叔丁基过氧化氢为氧源时则主要产物为苯甲醛;在极性溶剂中的催化氧化产率较高。轴向配体对催化氧化有促进作用,不同轴向配体对催化反应产率提高的顺序是：1-甲基咪唑 >吡啶 >咪唑。     

The crystal and molecular structure of the steroidal alkaloid 20-epi-kibataline

The major constituent of the alkaloid fraction of the leaves of Paravallaris macrophylla Pierre has found to be the new paravallarine-type steroidal alkaloid 20-epi-kibataline. The structure of this steroidal alkaloid has been determined by X-ray analysis. The compound crystallizes in the monoclinic space group P2₁ with the lattice parameters a = 11.286, b = 14.250, c = 6.206 Å, β = 97.88°. The final R value was 0.067.     

Crystal and molecular structure of 9-vinyladenine

The title compound 9-vinyladenine crystallizes in the monoclinic space group C2/c with 16 molecules in the unit cell and the lattice parameters a = 13.682, b = 10.250, c = 21.674 Å, β = 97.72°. The crystal structure has been determined by direct methods and refined by full matrix least squares calculations up to the discrepancy factor R = 0.045. The two symmetry independent molecules differ in the orientation of the vinyl group relative to the adenine frame.     

The Crystal and Molecular Structure of 1α,2α-Methylene Gibberellin A3 Methyl Ester

The three-dimensional structure of the 1α,2α-methylene gibberellin A₃ methyl ester has been determined by single-crystal X-ray diffraction techniques. The crystals are monoclinic, space group P 2₁ with two molecules in the unit cell of dimensions a = 9.236, b = 7.109, c = 14.155 Å and β = 104.61º. The structure was refined to an R-value of 0.0983 for 1359 observed reflections.     

Phase transition in electrorheological plasmas

Applying an external electric AC field to a dusty plasma, the micro-particles arrange in strings or chains. In analogy to electrorheological fluids, such a system is called electrorheological plasma. Turning gradually the AC field into a DC field, the string formation is diminished until it vanishes completely in the DC case. In this way, a cross-over transition from a string-like to an isotropic micro-particle many-body system can be investigated. Experimental investigations of electrorheological plasmas are performed under microgravity conditions in parabolic flights. For analysing the image data, a supervised machine learning code was developed and a continuous cross over was found. A molecular dynamics simulation showed qualitatively similar results but also some deviations from the experimental results.     

SERS as tool for the analysis of DNA-chips in a microfluidic platform

A sequence-specific detection method of DNA is presented combining a solid chip surface for immobilisation of capture DNAs with a microfluidic platform and a readout of the chip based on SERS. The solid chip surface is used for immobilisation of different capture DNAs, where target strands can be hybridised and unbound surfactants can be washed away. For the detection via SERS, short-labelled oligonucleotides are hybridised to the target strands. This technique is combined with a microfluidic platform that enables a fast and automated preparation process. By applying a chip format, the problems of sequence-specific DNA detection in solution phase by means of SERS can be overcome. With this setup, we are able to distinguish between different complementary and non-complementary target sequences in one sample solution.