35 research outputs found
New chiral complexes of palladium(0) containing P,S- and P,P-bidentate ligands
No full textNew chiral complexes of Pd(O) containing either the bis(phosphine) (6,6'-dimethoxybiphenyl-2,2'-diyl)bis(3,5-di-tert -butylphenylphosphine) (MeO-BIPHEP, 1) or the phosphine-sulfur chelate (2,3,4,6-tetra-O-acetyl-1-{(2-diphenylphosphino)benzyl)thio) -beta-D-glucopyranose ((2-Ph2PC6H4CH2) -S-CHCH(OAc)CH(OAc)CH(OAc)CH(CH2OAc)O,2) have been prepared, and the solid-state structure of one of these, Pd(benzoquinone)(2), has been determined. These Pd(O) complexes reveal interesting solution dynamics, as shown by 2-dimensional exchange spectroscopy. For the MeO-BIPHEP derivatives, one can obtain useful structural insights based on the observed restricted rotation around the aryl(3,5-di-tert-butylphenl)P-C bonds
Einfluss von Hemisphärenasymmetrien, dem Geschlecht, dem Pubertätsbeginn und pränatalen Hormonen auf die Persönlichkeit
No full textDas Ziel der vorliegenden Studie war bestehende Ergebnisse zum ?Kongruenzmodell der Hemisphärenasymmetrie? zu replizieren bzw. inkonsistente Ergebnisse durch eine Erweiterung des Versuchsdesigns zu erklären. Hierzu wurden zusätzlich das Geschlecht, das Fingerlängenverhältnis (FLV) und der Pubertätsbeginn miterhoben. Grundgedanke der Studie war, dass eine für das Geschlecht untypische pränatale Hormonexposition oder ein untypischer Pubertätsbeginn Grundlage für bisher gegensätzliche Ergebnisse sind. Um die Aktivierungsasymmetrien abzubilden wurden voneinander unabhängige behaviorale Lateralitätsmaße kombiniert (Händigkeit, Chimärische Gesichter, Dichotisches Hören, perzeptive und motorische Linienhalbierung) und analysiert, ob zusammen mit den zusätzlich erhobenen Variablen Unterschiede in der Persönlichkeit erklärbar sind. Hierzu wurden Fragebogen zur Schizotypie, den Big Five und Eysenck´s Persönlichkeitstheorie vorgelegt. Der Pubertätsbeginn wurde mittels Adoleszenzfragebogen und das FLV durch Scannen der Handflächen erhoben. Die Annahmen wurden an 209 Studierenden (107 Frauen, 102 Männer) im Alter von 19 bis 45 Jahren mittels multivariater Varianzanalysen überprüft. Es konnte gezeigt werden, dass eine untypische Pubertät und eine untypische pränatale Hormonsituation Einfluss auf einzelne Persönlichkeitseigenschaften haben könnten.The aim of the present study was to replicate existing findings respectively elucidate inconsistent findings of the ?Kongruenzmodell der Hemisphärenasymmetrie? by an extension of the experimental design. Additionally sex, second-to-fourth finger length ratio (2d:4d) and age at puberty were investigated. Main theory of the study was, that an atypical age at puberty or an atypical 2d:4d is the key to success and the interaction of interindividual differences in hemispheric specialization and the additional variables could explain differences in personality. For this purpose several personality questionnaires were presented (Schizotypal Personality Questionnaire, Big Five Inventory, Eysenck Personality Inventory) and furthermore a German version of the Adolescence Scale. Both hands were scanned to calculate the 2d:4d and five behavioural laterality measures (degree of right-handedness, ear dominance, motoric and perceptual line bisection performance, processing positive facial emotion) were examined to survey the interindividual differences in hemispheric specialization. The assumptions were tested with 209 students (107 female, 102 male) aged between 19 and 45 years by use of multivariate analysis of variance. Results show that an atypical age at puberty and 2d:4d could have influence on different aspects of personality.von Claudia TrabesingerGraz, Univ., Dipl.-Arb., 200
New Chiral Complexes of Palladium(0) Containing P,S- and P,P-Bidentate Ligands
No full textNew chiral complexes of Pd(0) containing either the
bis(phosphine) (6,6‘-dimethoxybiphenyl-2,2‘-diyl)bis(3,5-di-tert-butylphenylphosphine)
(MeO-BIPHEP, 1) or the phosphine−sulfur
chelate
(2,3,4,6-tetra-O-acetyl-1-{(2-diphenylphosphino)benzyl)thio}-β-d-glucopyranose
((2-Ph2PC6H4CH2)−S−CHCH(OAc)CH(OAc)CH(OAc)CH(CH2OAc)O,
2) have been prepared, and
the solid-state structure of one of these,
Pd(benzoquinone)(2), has been determined.
These
Pd(0) complexes reveal interesting solution dynamics, as shown by
2-dimensional exchange
spectroscopy. For the MeO-BIPHEP derivatives, one can obtain
useful structural insights
based on the observed restricted rotation around the
aryl(3,5-di-tert-butylphenyl) P−C bonds
Anisotrope dynamische Dauerfestigkeitsberechnung einer geschmiedeten Kurbelwelle – Vorstellung neuer Berechnungsmöglichkeiten durch Berücksichtigung von Materialeffekten aus der Herstellung
No full textPalladium−Allyl Complexes Based on 3,17-Dioxo-4-androstene. The Solid-State Structure of [Pd(η<sup>3</sup>-C<sub>19</sub>H<sub>29</sub>O<sub>2</sub>)(R-Binap)]PF<sub>6</sub>
No full textSeveral π-allyl compounds of the form
[Pd(η3-C19H29O2)(bidentate)](anion),
derived from
3,17-dioxo-4-androstene, have been prepared (bidentate =
R-Binap, 3a; S,S-Chiraphos,
3b;
(6,6‘-dimethoxybiphenyl-2,2‘-diyl)bis(3,5-di-tert-butylphenylphosphine),
MeO-Biphep, 3c; the
P,S-chelate
(2,3,4,6-tetra-O-acetyl-1-(2-diphenylphosphino)benzylthio)-β-D-glucopyranose),
7, phenanthroline, 8, and neocuproin,
9). The solid-state structure of
[Pd(η3-C19H29O2)(R-Binap)]PF6 has been determined by X-ray diffraction
methods. It is suggested that 3a (and
presumably other relatively large allyl complexes) accommodates the two
large ligands by
both hinging the allyl plane away from the Binap and rotating the allyl
ligand. Selected
aspects of the solution dynamics for 3a, 3c, and
9 have been followed by NOESY methods.
Allyl 13C NMR data are reported for the complexes
A structural model of pestivirus E(rns) based on disulfide bond connectivity and homology modeling reveals an extremely rare vicinal disulfide
No full textErns is a pestivirus envelope glycoprotein and is the only known viral surface protein with RNase activity. Erns is a disulfide-linked homodimer of 100 kDa; it is found on the surface of pestivirus-infected cells and is secreted into the medium. In this study, the disulfide arrangement of the nine cysteines present in the mature dimer was established by analysis of the proteolytically cleaved protein. Fragments were obtained after digestion with multiple proteolytic enzymes and subsequently analyzed by liquid chromatography-electrospray ionization mass spectrometry. The analysis demonstrates which cysteine is involved in dimerization and reveals an extremely rare vicinal disulfide bridge of unknown function. With the assistance of the disulfide arrangement, a three-dimensional model was built by homology modeling based on the alignment with members of the Rh/T2/S RNase family. Compared to these other RNase family members, Erns shows an N-terminal truncation, a large insertion of a cystine-rich region, and a C-terminal extension responsible for membrane translocation. The homology to mammalian RNase 6 supports a possible role of Erns in B-cell depletion
Electrochemical impedance spectroscopy of a Li–S battery: Part 2. Influence of separator chemistry on the lithium electrode/electrolyte interface
No full textInternational audienc
A Bimetallic Palladium Catalyst for Asymmetric Allylic Substitution Reactions<sup>†</sup>
No full textWith 1,1‘-diacetylruthenocene (9) as starting material,
the preparation of 1,1‘-bis[1-(1-{(R)-1-[(S)-2-(diphenylphosphino)ferrocenyl]ethyl})-1H-pyrazol-3-yl]ruthenocene
((R,R)-(S,S)-12) is attained in three steps. 12
coordinates to two independent Pd(II)−π-allyl units
to
form the dicationic complex 15, isolated as a
bis(hexafluorophosphate) salt. This has been
characterized by X-ray and 2D NMR methods in solution, along with the
analogous derivative
14, which contains
1-{(R)-1-[(S)-2-(diphenylphosphino)ferrocenyl]ethyl}-3-ruthenocenyl-1H-pyrazole ((R)-(S)-8b). The three
Pd(II)−allyl fragments in these two complexes show
very
similar conformational features. In the Pd-catalyzed substitution
reaction of ethyl (1,3-diphenylallyl)carbonate (1) with benzylamine, the
bimetallic catalyst containing ligand 12
and the mononuclear catalyst formed by 8b afford the same
high enantioselectivity (99.3%)
Unraveling gas evolution in sodium batteries by online electrochemical mass spectrometry
No full textInternational audienceIdentification of gaseous decomposition products from irreversible side-reactions enables understanding of inner working of rechargeable batteries. Unlike for Li-ion batteries, the knowledge of the gas-evolution processes in Na-ion batteries is limited. Therefore, in this study, we have performed online electrochemical mass spectrometry to understand gassing behavior of model electrodes and electrolytes in Na-ion cells. Our results show that a less stable solid–electrolyte interphase (SEI) layer is developed in Na-ion cells as compared with that in Li-ion cells, which is mainly caused by higher solubility of SEI constituents in Na-electrolytes. Electrolyte reduction on the anode has much larger contribution to the gassing in the Na-ion cells, as gas evolution comes not only from direct electrolyte reduction but also from the soluble species, which migrate to the cathode and are decomposed there. During cell cycling, linear carbonates do not form an SEI layer on the anode, resulting in continuous electrolyte reduction, similar to Li-ion system but with much higher severity, while cyclic carbonates form a more stable SEI, preventing further decomposition of the electrolyte. Besides the standard electrolyte solvents, we have also assessed effects of several common electrolyte additives in their ability to stabilize the interphases. The results of this study provide understanding and guidelines for developing more durable electrode–electrolyte interphase, enabling higher specific energy and improved cycling stability for Na-ion batteries
