Thiophene-substituted fulleropyrrolidine derivatives as acceptor molecules in a thin film organic solar cell

A study of the design of thiophene-substituted fulleropyrrolidine derivatives as the acceptor in photovoltaic cells has been carried out using poly(3-hexylthiophene) (P3HT) as the model donor polymer. It was found that five types of thiophene-substituted fulleropyrrolidine worked as a good acceptor partner with P3HT, and the highest power conversion efficiency (PCE) was obtained for 1-(2-(2-methoxyethoxy)ethyl)-2-(2-thiophen-2-yl)fulleropyrrolidine (2.99%); this is superior to that of the P3HT polymer including methyl [C60]-PCBM under the same experimental conditions.     

Enantioselective synthesis of gabapentin analogues via organocatalytic asymmetric Michael addition of α-branched aldehydes to β-nitroacrylates

Michael addition reaction of α-branched aldehydes to β-nitroacrylates was successfully carried out by using a mixed catalyst consisting of a primary amino acid, L-phenylalanine, and its lithium salt to give β-formyl-β'-nitroesters having a quaternary carbon centre in good yields (up to 85%) with high enantioselectivity (up to 98% ee). By using benzyl β-nitroacrylates as Michael acceptors, the obtained β-formyl-β'-nitroesters were converted into various 4,4-disubstituted pyrrolidine-3-carboxylic acids including analogues of gabapentin (Neurotin(?)) in one step from the Michael adducts in high yields.     

Realtime 3D profile measurement by using the composite pattern based on the binary stripe pattern

In this paper, a one-shot composite pattern based on three-step binary stripe pattern is developed to meet the demand of real-time 3D shape measurement for complicated objects. Theoretical analysis and numerical simulation prove that the proposed pattern can provide higher accuracy than the composite pattern based on the traditional three-step phase shifting. Furthermore, the significant advantage for the proposed composite pattern is that it can provide the unique location of the stripe boundary, resulting in the elimination of the ambiguity which usually arises for measurement of complicated object with the phase shifting method. The proposed composite pattern has been implemented to measure three different complicated objects. The results demonstrate that it is appropriate for the real-time 3D shape measurement.     

Development of palladium-catalyzed transformations using propargylic compounds

It is known that propargylic compounds having an ester and a halide at the propargylic positions react with palladium complexes leading to π-propargylpalladium and allenylpalladium complexes, which cause various transformations in the presence of the reactants. The aim of the present study was to develop novel palladium-catalyzed transformations using propargylic compounds. As diastereoselective reactions of propargylic compounds with bis-nucleophiles, we have developed palladium-catalyzed reactions of propargylic carbonates with 2-substituted cyclohexane-1,3-diones, 2-(2-hydroxyphenyl)acetates and 2-oxocyclohex-3-enecarboxylates. These processes produce highly substituted cyclic compounds in a highly stereoselective manner. Through our studies on the construction of substituted 2,3-allenols by the reactions of propargylic oxiranes, it has been made clear that palladium-catalyzed coupling reactions occur in the presence of arylboronic acids and terminal alkynes. The processes can be carried out in mild conditions to yield substituted 4-aryl-2,3-allenols in a diastereoselective manner. In our attempt to develop CO2-recycling reactions, we developed a methodology for the synthesis of cyclic carbonates by palladium-catalyzed reactions of propargylic carbonates with phenols. Our findings suggested that the process proceeds through a pathway involving decarboxylation-followed fixation of the liberated CO2. Diastereoselective, enantioselective, and enantiospecific construction of cyclic carbonates have been achieved by the application of this methodology.     

Synthesis and characterization of Th2N2(NH) isomorphous to Th2N3

Using a new, low-temperature, fluoride-based process, thorium nitride imide of the chemical formula Th(2)N(2)(NH) was synthesized from thorium dioxide via an ammonium thorium fluoride intermediate. The resulting product phase was characterized by powder X-ray diffraction (XRD) analysis and was found to be crystallographically similar to Th(2)N(3). Its unit cell was hexagonal with a space group of P3m1 and lattice parameters of a = b = 3.886(1) and c = 6.185(2) ?. The presence of -NH in the nitride phase was verified by Fourier transform infrared spectroscopy (FTIR). Total energy calculations performed using all-electron scalar relativistic density functional theory (DFT) showed that the hydrogen atom in the Th(2)N(2)(NH) prefers to bond with nitrogen atoms occupying 1a Wyckoff positions of the unit cell. Lattice fringe disruptions observed in nanoparticle areas of the nitride species by high-resolution transmission electron microscopic (HRTEM) images also displayed some evidence for the presence of -NH group. As ThO(2) was identified as an impurity, possible reaction mechanisms involving its formation are discussed.     

Assessing continuum postulates in simulations of granular flow

Continuum mechanics relies on the fundamental notion of a mesoscopic volume “element” in which properties averaged over discrete particles obey deterministic relationships. Recent work on granular materials suggests that a continuum law may be inapplicable, revealing inhomogeneities at the particle level, such as force chains and slow cage breaking. Here, we analyze large-scale three-dimensional discrete-element method (DEM) simulations of different granular flows and show that an approximate “granular element” defined at the scale of observed dynamical correlations (roughly three to five particle diameters) has a reasonable continuum interpretation. By viewing all the simulations as an ensemble of granular elements which deform and move with the flow, we can track material evolution at a local level. Our results confirm some of the hypotheses of classical plasticity theory while contradicting others and suggest a subtle physical picture of granular failure, combining liquid-like dependence on deformation rate and solid-like dependence on strain. Our computational methods and results can be used to guide the development of more realistic continuum models, based on observed local relationships between average variables.