Revised structure of cercidinin A, a novel ellagitannin having (R)-hexahydroxydiphenoyl esters at the 3,4-positions of glucopyranose

The structure of cercidinin A, an ellagitannin isolated from the bark of Cercidiphyllum japonicum, was revised to 1,2,6-tri-O-galloyl-3,4-(R)-hexahydroxydiphenoyl-beta-D-glucose by two-dimensional NMR spectral analysis. Cercidinin A represents the first ellagitannin possessing a hexahydroxydiphenoyl group at the 3,4-positions of a modified 4C1-glucopyranose core.     

On the extremum property of electron density functions in position and momentum spaces

For statistically uncorrelated wave functions, the electron density ρ(r) is known to be an extremum function of the generalized electron-pair density g(q;a,b), which smoothly connects ρ(r), the electron-pair intracule (relative motion) density h(u), and the electron-pair extracule (center-of-mass motion) density d(R). The present systematic examination of the numerical Hartree–Fock results of moments rⁿ, uⁿ, Rⁿ and density values at the origin ρ(0), h(0), d(0) for 102 neutral atoms and 96 singly charged ions suggests that ρ(r) is local maximum for a small q and is local minimum for a large q of the function g(q;a,b). Analogous results are obtained for the momentum-space counterparts Π(p) and .     

Role of CH, CH3, and OH Radicals in Organic Compound Decomposition by Water Plasmas

Decomposition of acetone, methanol, ethanol, and glycerine by water plasmas at atmospheric pressure has been investigated using a direct current discharge. At torch powers of 910–1,050 W and organic compound concentrations of 1–10 mol%, the decomposition rate of methanol and glycerine was over 99%, while those of acetone and ethanol was 95.4–99%. The concentrations of H₂ obtained were 60–80% in the effluent gas for any compounds by pyrolysis. Based on the experimental results, the decomposition mechanism of organic compounds in water plasmas was proposed and the roles of intermediate species such as CH, CH₃, and OH have been investigated; CH radical generated from organic compounds decomposition was easily oxidized to form CO; incomplete oxidation of CH₃ leads to C₂H₂ generation as well as soot formation; and negligible amount of soot observed from glycerine decomposition even at high concentration indicated that oxidation of CH_×(×:1–3) was enhanced by OH radical.     

Relativistic segmented contraction basis sets with core-valence correlation effects for atoms 57La through 71Lu: Sapporo-DK-nZP sets (n?=?D, T, Q)

For the 15 lanthanide atoms ₅₇La through ₇₁Lu, we report Sapporo-DK-nZP sets (n?=?D, T, Q), which are natural extensions of the Sapporo-(DK)-nZP sets for lighter atoms and efficiently incorporate the correlation among electrons in the N through P shells as well as the relativistic effect. The present sets well describe the correlation among the 4s and 4p electrons, which are important in the excitation of 4f electrons. Atomic test calculations of ₅₇La, ₅₈Ce, ₅₉Pr, and ₆₀Nd at configuration interaction with the Davidson correction level of theory confirm high performance of the present basis sets. Molecular test calculations are carried out for ₅₇LaF and ₇₀YbF diatomics at the coupled-cluster level of theory. The calculated spectroscopic constants approach smoothly to the experimental values as the quality of the basis set increases.     

Modeling strain hardening of polydisperse polystyrene melts by molecular stress function theory

The strain hardening of blends of polystyrene (PS) and ultra-high molecular weight polystyrene (UHMW-PS) in elongational flow is modeled by the molecular stress function (MSF) theory. Assuming that the ratios of strain energies stored in polydisperse and monodisperse polymers are identical for linear and nonlinear deformations, the value of the only non-linear parameter of the theory in extensional flows, the maximum molecular stress f_max, can be determined and is shown to be related to steady-state compliance J_e0. Using only linear-viscoelastic data, the elongational viscosity of PS/UHMW-PS blends is consistently predicted by the MSF theory.     

Electronic coupling calculation and pathway analysis of electron transfer reaction using ab initio fragment-based method. I. FMO-LCMO approach

By making use of an ab initio fragment-based electronic structure method, fragment molecular orbital-linear combination of MOs of the fragments (FMO-LCMO), developed by Tsuneyuki et al. [Chem. Phys. Lett. 476, 104 (2009)], we propose a novel approach to describe long-distance electron transfer (ET) in large system. The FMO-LCMO method produces one-electron Hamiltonian of whole system using the output of the FMO calculation with computational cost much lower than conventional all-electron calculations. Diagonalizing the FMO-LCMO Hamiltonian matrix, the molecular orbitals (MOs) of the whole system can be described by the LCMOs. In our approach, electronic coupling T(DA) of ET is calculated from the energy splitting of the frontier MOs of whole system or perturbation method in terms of the FMO-LCMO Hamiltonian matrix. Moreover, taking into account only the valence MOs of the fragments, we can considerably reduce computational cost to evaluate T(DA). Our approach was tested on four different kinds of model ET systems with non-covalent stacks of methane, non-covalent stacks of benzene, trans-alkanes, and alanine polypeptides as their bridge molecules, respectively. As a result, it reproduced reasonable T(DA) for all cases compared to the reference all-electron calculations. Furthermore, the tunneling pathway at fragment-based resolution was obtained from the tunneling current method with the FMO-LCMO Hamiltonian matrix.     

Synthesis and oxygen permeation properties of 75 mol% Ce0.75Nd0.25O1.875–25 mol% Nd1.8Ce0.2CuO4 composite

An oxygen-permeable composite constituted to oxide ionic conductor phase (Ce_0.75Nd_0.25O_1.875) and oxide electronic conductor phase (Nd_1.8Ce_0.2CuO₄) was prepared using the acetate pyrolysis method. Based on electrical conductivity measurements, total electrical conductivity of 75 mol% Ce_0.75Nd_0.25O_1.875–25 mol% Nd_1.8Ce_0.2CuO₄ composite material was governed by the electronic conduction paths. With respect to the oxygen permeation properties, the results showed that oxygen permeation properties were unexplainable by a simple composite rule using the electrical transport properties of the bulk Ce_0.75Nd_0.25O_1.875 and the bulk Nd_1.8Ce_0.2CuO₄.     

Algebraic Independence of Reciprocal Sums of Binary Recurrences II

 Algebraic independence of the numbers for various d and l, where is a periodic sequence of algebraic numbers and is a sequence of integers satisfying a binary linear recurrence relation, is studied by Mahler’s method. Received 25 August 2000; in revised form 8 January 2002