Photoreactivity of 5-iodouracil-containing DNA-Sso7d complex in solution: the protein-induced DNA kink causes intrastrand hydrogen abstraction from the 5-methyl of thymine at the 5' side

Photoirradiation of 5-iodouracil-containing DNA, d(GTAAT(I)UAC)(2) with Sso7d protein, possessing significant kink in DNA in the crystal structure induces an unprecedented intrastrand H abstraction at the methyl group of T(5), together with selective photooxidations at Met29 of Sso7d. The reactivity of the deoxyuridin-5-yl radical can be explained by the crystal structure of the d(GTAATTAC)(2)-Sso7d complex, suggesting that the interaction of DNA-Sso7d in solution is substantially similar to its crystal structure.     

Über die Einwirkung von Thiolen und Sulfinsäuren auf Chinolacetate, 2. Mitt

Zusammenfassung In Fortsetzung einer früheren Arbeit wird die Addition von H₂S und Verbindungen der Typen RSH und RSO₂H (RC₆H₅) in verschiedenen Lösungsmitteln mit verschiedenen basischen Katalysatoren an verschiedene o-Benzochinolacetate und auch an ein o-Benzochinondiacetat untersucht. Zum Unterschied von C₆H₅SH geben die oben erwähnten Thiole auch m-.bzw. o-Substitution. Die Methansulfinsäure wird wie die Benzolsulfinsäure in 1,4-Stellung addiert. Die Abhängigkeit der Additionsstelle vom Lösungsmittel und Katalysator ist von theoretischem Interesse, weil sie zeigt, daß die hier beschriebenen Additionsreaktionen nicht durch Grenzstrukturen beschrieben werden können, wie sie sonst mit Erfolg bei Additionsreaktionen acyclischer , -ungesättigter Ketone verwendet werden.     

Wrinkle-Based Measurement of Elastic Modulus of Nano-Scale Thin Pt Film Deposited on Polymeric Substrate: Verification and Uncertainty Analysis

Wrinkle-based measurement of elastic modulus for a nano-scale thin film was analyzed. As a demonstrative example, the wrinkles of Pt films on a Polydimethylsiloxane (PDMS) substrate under compressive loading were formed with a well-defined wavelength, corresponding to the difference of elastic moduli between the films and substrates. The elastic modulus of the Pt nano-scale thin film measured with the wrinkle-based measurement was found to be consistent with that independently measured with micro-tensile test. Uncertainty of the wrinkle-based measurement was analyzed to figure out the main uncertainty components for the evaluation of elastic modulus measurement, and guidelines for the reliable wrinkle-based measurement were suggested.     

Die Konstitution des Phlorrhizins

Ohne Zusammenfassung     

Über Carbonyl-bis-aminosäuren und deren Umwandlungsprodukte II

Ohne Zusammenfassung     

Syntheses and structural properties of rare earth carbodiimides

Crystalline samples of rare earth carbodiimides were synthesized by solid-state metathesis reactions of rare earth trichlorides with lithium cyanamide in sealed silica ampules. Two distinct structures were determined by single-crystal X-ray diffraction. The structure determined for Sm2(CN2)3 [C2/m, Z = 2, a = 14.534(2) A, b = 3.8880(8) A, c = 5.2691(9) A, beta = 95.96(2) degrees , R1 = 0.0267, and wR2 = 0.0667] was assigned for RE2(CN2)3 compounds with RE = Y, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Er, and the structure determined for Lu2(CN2)3 [R32, Z = 3, a = 6.2732(8) A, c = 14.681(2) A, R1 = 0.0208, and wR2 = 0.0526] was assigned for the smallest rare earth ions with RE = Tm, Yb, and Lu by powder X-ray diffraction. Both types of crystal structures are characterized by layers of [NCN](2-) ions whose arrangements can be derived from the motif of a closest packed layer of sticks. These layers alternate with layers of rare earth ions in a one-by-one sequence. Different tilting arrangements of the N-C-N-axes relative to the stacking directions (c) and different arrangements of RE3+ ions within metal atom layers account for the two distinct structures in which Sm3+ and Lu3+ ions adopt the coordination numbers 7 and 6, respectively.     

Spin state transition in LaCoO3 studied using soft x-ray absorption spectroscopy and magnetic circular dichroism

Using soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co-L(2,3) edge, we reveal that the spin state transition in LaCoO3 can be well described by a low-spin ground state and a triply degenerate high-spin first excited state. From the temperature dependence of the spectral line shapes, we find that LaCoO3 at finite temperatures is an inhomogeneous mixed-spin state system. It is crucial that the magnetic circular dichroism signal in the paramagnetic state carries a large orbital momentum. This directly shows that the currently accepted low- or intermediate-spin picture is at variance. Parameters derived from these spectroscopies fully explain existing magnetic susceptibility, electron spin resonance, and inelastic neutron data.     

Photo-induced desorption of NO from NiO(100): calculation of the four-dimensional potential energy surfaces and systematic wave packet studies

The velocity distributions of the laser-induced desorption of NO molecules from an epitaxially grown film of NiO(100) on Ni(100) have been studied [Mull et al., J. Chem. Phys., 1992, 96, 7108]. A pronounced bimodality of velocity distributions has been found, where the NO molecules desorbing with higher velocities exhibit a coupling to the rotational quantum states J. In this article we present simulations of state resolved velocity distributions on a full ab initio level. As a basis for this quantum mechanical treatment a 4D potential energy surface (PES) was constructed for the electronic ground and a representative excited state, using a NiO5Mg(18+)13 cluster. The PESs of the electronic ground and an excited state were calculated at the CASPT2 and the configuration interaction (CI) level of theory, respectively. Multi-dimensional quantum wave packet simulations on these two surfaces were performed for different sets of degrees of freedom. Our key finding is that at least a 3D wave packet simulation, in which the desorption coordinate Z, polar angle theta and lateral coordinate X are included, is necessary to allow the simulation of experimental velocity distributions. Analysis of the wave packet dynamics demonstrates that essentially the lateral coordinate, which was neglected in previous studies [Klüner et al., Phys. Rev. Lett. 1998, 80, 5208], is responsible for the experimentally observed bimodality. An extensive analysis shows that the bimodality is due to a bifurcation of the wave packet on the excited state PES, where the motion of the molecule parallel to the surface plays a decisive role.