N-(2,6-Dihalobenzoyl)-N′-pyrimidinylharnstoffe

N-(2,6-Dichlorobenzoyl)- and N-(2,6-difluorobenzoyl)-N-pyrimidinylureas3b–3n have been synthesized by reaction of the corresponding aminopyrimidine derivatives with 2,6-dichlorobenzoyl isocyanate or 2,6-difluorobenzoyl isocyanate. The insecticidal activity of compounds3b–3n has been evaluated.

     

(Cycloheptatrienyl)hydridotungsten Complexes

Carbonyl(cycloheptatrienyl)iodo(phosphorus donor)tungstens ([WI(C₇H₇)(CO)L]; L = P(OMe)₃, 1a ; L = P[O(i-Pr)]₃, 1b ; L = PPh₃, 1c ) were prepared from dicarbonyl(cycloheptatrienyl)iodotungsten ([WI(C₇H₇)(CO)₂)] via a carbonyl-substitution process. Similarly, bromocarbonyl(phosphorus donor)(1,2,4,6-tetramethylcycloheptatrienyl)tungstens ([WBr(Me₄C₇H₃)(CO)L]; L = P(OMe)₃, 6a ; L = P[O(i-Pr)]₃, 6b ; L = PPh₃, 6c ) were obtained from the reaction of bromodicarbonyl(1,2,4,6)-tetramethylcycloheptatrienyl)tungsten ([WBr(Me₄C₇H₃)(CO)₂]; 4 ) with L. The reduction of 1a - c , 4 , and 6a , b with sodiumdihydridobis(2-methoxyethoxy)aluminium in toluene led to stable hydrido complexes [WH(R₄C₇H₃)(CO)L] (R = H, L = P(OMe)₃, 2a ; R = H, L = P[O(i-Pr)]₃, 2b ; R = H, L = PPh₃, 2c ; R = Me, L = P(OMe)₃, 7a ; R = Me, L = P[O(i-Pr)]₃, 7b ; R = Me, L = CO, 7d ). Complexes 2a and 7b were characterized by X-ray structure analyses.     

Experimental design-based development and single laboratory validation of a capillary zone electrophoresis method for the determination of the artificial sweetener sucralose in food matrices

A capillary zone electrophoresis (CZE) method, optimised chemometrically, underwent a complete in-house validation protocol for the qualification and quantification of sucralose in various foodstuffs. Separation from matrix components was obtained in a dinitrobenzoic acid (3 mM)/sodium hydroxide (20 mM) background electrolyte with a pH of 12.1, a potential of 0.11 kV cm^–1 and a temperature of 22 °C. Detection was achieved at 238 nm by indirect UV. Screening, optimisation and robustness testing were all carried out with the aid of experimental design. Using standard addition calibration, the CZE method has been applied to still, carbonated and alcoholic beverages, yoghurts and hard-boiled candy. The method allows the detection of sucralose at >30 mg kg^–1, with a linearity range of 50–500 mg kg^–1, making it suitable for implementation of the recently amended Sweeteners for use in foodstuffs Directive (European Parliament and Council (2003) Off J L237:3–12), which set maximum usable doses of sucralose for many foodstuffs, most ranging from 200 mg kg^–1 to 450 mg kg^–1.     

The application of low energy ion scattering spectroscopy (LEIS) in sub 28‐nm CMOS technology

With the transition to ≤28‐nm CMOS technology nodes, the surface analytical challenges with regard to steadily decreasing dimensions and still growing materials options raise the demand of high performing surface analysis techniques. Characterization of ultrathin films and multilayer stacks, especially in high‐k metal gate stacks, by means of low energy ion scattering spectroscopy (LEIS) with its monolayer sensitivity has been established as a very useful analysis technique next to Auger electron spectroscopy, X‐ray photoelectron spectroscopy , and time‐of‐flight secondary ion mass spectrometry. Questions regarding film nucleation, growth, coverage, and diffusion can be answered, thereby enabling those processes to be controlled appropriately. In this work, growth studies of ALD HfO₂ and TiN are shown, as well as film thickness determination based on surface spectra. PVD aluminum and lanthanum, acting as work function metals on the gate oxide, were deposited, and their film formation and closure were investigated. Further application fields of LEIS have emerged from the characterization of in‐die features on patterned wafers. As presented on test arrays, it is possible to detect material deep in trenches. This is an advantage if residues need to be identified after etch or clean processes.     

Biosynthesis and structure of aeruginoside 126A and 126B, cyanobacterial peptide glycosides bearing a 2-carboxy-6-hydroxyoctahydroindole moiety

Aeruginosins represent a group of peptide metabolites isolated from various cyanobacterial genera and from marine sponges that potently inhibit different types of serine proteases. Members of this family are characterized by the presence of a 2-carboxy-6-hydroxyoctahydroindole (Choi) moiety. We have identified and fully sequenced a NRPS gene cluster in the genome of the cyanobacterium Planktothrix agardhii CYA126/8. Insertional mutagenesis of a NRPS component led to the discovery and structural elucidation of two glycopeptides that were designated aeruginoside 126A and aeruginoside 126B. One variant of the aglycone contains a 1-amino-2-(N-amidino-Delta(3)-pyrrolinyl)ethyl moiety at the C terminus, the other bears an agmatine residue. In silico analyses of the aeruginoside biosynthetic genes aerA-aerI as well as additional mutagenesis and feeding studies allowed the prediction of enzymatic steps leading to the formation of aeruginosides and the unusual Choi moiety.     

Towards J/mol Accuracy for the Cohesive Energy of Solid Argon

The cohesive energies of argon in its cubic and hexagonal closed packed structures are computed with an unprecedented accuracy of about 5 J mol^?1 (corresponding to 0.05 % of the total cohesive energy). The same relative accuracy with respect to experimental data is also found for the face‐centered cubic lattice constant deviating by ca. 0.003 Å. This level of accuracy was enabled by using high‐level theoretical, wave‐function‐based methods within a many‐body decomposition of the interaction energy. Static contributions of two‐, three‐, and four‐body fragments of the crystal are all individually converged to sub‐J mol^?1 accuracy and complemented by harmonic and anharmonic vibrational corrections. Computational chemistry is thus achieving or even surpassing experimental accuracy for the solid‐state rare gases.     

Pilot study of capillary electrophoresis coupled to mass spectrometry as a tool to define potential prostate cancer biomarkers in urine

We describe the use of capillary electrophoresis (CE) coupled with mass spectrometry (MS) to identify single polypeptides and patterns of polypeptides specific for prostate cancer (CaP) in human urine. Using improved sample preparation methods that enable enhanced comparability between different samples, we examined samples from 47 patients who underwent prostate biopsy. Of this group, 21 patients had benign pathology and 26 with CaP, and these were used to define potential biomarkers, which allow discrimination between these two states. In addition, CE-MS data from these 47 urine samples were compared to that of 41 young men (control) without known or suspected clinical CaP to further confirm the polypeptides indicative for CaP. Upon crossvalidation of the same samples, several polypeptides were selected that enabled correct classification of the CaP patients with 92% sensitivity and 96% specificity. We then examined an additional 474 samples from patients with renal disease enrolled in other studies and found that 14 (3%) had polypeptides suggestive of CaP possibly indicating that they harbor clinical CaP. In conclusion, this early pilot study suggests that CE-MS of urine warrants further investigation as a tool that can identify putative biomarkers for CaP.