A novel synthesis of (±)-descarboxyquadrone

The novel synthesis of descarboxyquadrone (3) and its model compound (4) by using the acid-catalyzed rearrangement of [4.3.2]propellanones is described.     

Biooxidation of a synthetic waste by a microbial film grown on the liquid surface in a shallow flow reactor

A new process of biological waste treatment was developed by use of microbial films grown on the liquid surface in a shallow flow reactor. The performance of this process was tested using a synthetic waste that contained acetic acid as a model organic pollutant. About 90% of acetic acid (10,000 mg/L-1) in the synthetic waste was removed by setting alpha tau: (alpha specific liquid surface area, cm-1, and tau: hydraulic liquid detention time, h) higher than 15 cm-1/h. It was necessary to maintain alpha large enough (more than 10 cm-1 in most cases) to satisfy oxygen demand for the biooxidation. The oxygen balance and TOC determinations showed that the acetic acid removed was completely oxidized with oxygen transferred through the liquid surface. This process would contribute to energy savings, since it requires no forced aeration for oxygen supply.     

Aggregation behavior of latex particles in shear flow confined between two parallel plates

In this study, the aggregation and breakup behaviors of latex particles in shear flow confined between two parallel plates were investigated using an in situ observation apparatus with a laser scanning confocal microscope. To investigate the effects of shear rate and the gap width between two parallel plates on the size and structure of the aggregates in the steady state, the distributions of the projected cross-sectional area and perimeter-based fractal dimension of the aggregates were measured. As a result, the average size of the aggregates decreases as shear rate increases and the gap width decreases due to the hydrodynamic effect acting on the aggregates. The size distributions of the aggregates become narrow as the gap width decreases. In addition, the fractal dimension, that is, the structure of the aggregates, was almost independent of shear rate and the gap width and approximately 1.2, which suggests that the aggregates are relatively compact.     

Synthesis of N,N,N′,N′-tetrasubstituted 1,3-bis(4-aminophenyl)azulenes and their application to a hole-injecting material in organic electroluminescent devices

After a preliminary search of the reaction conditions for the Suzuki-Miyaura cross-coupling of haloazulenes with arylboronic acids, the title compounds were synthesized either by the direct coupling reaction between 1,3-dihaloazulene and the corresponding N,N-disubstituted 4-aminophenylboronic acids or by a two-step sequence involving the cross-coupling with 4-bromophenylboronic acid and subsequent Pd-catalyzed amination. Application of the title diamines to a hole-injecting material in organic electroluminescent devices was carried out to provide their prominent characteristics as a novel durable, non-cyanine and non-polyamine substance without color fade. The diamine derivatives, extended by an ethynyl unit between the azulenyl core and the 4-aminophenyl moiety, were also synthesized and found, unfortunately, unsuitable for vacuum deposition in preparing a multilayer composite.     

Synthesis and utility of 3-silylthiophenes having perfluoroalkyl groups

The synthesis of a novel class of 3-silyl substituted thiophenes possessing perfluoroalkyl groups on the silicon atom was investigated. The treatment of 3-bromothiophene with n-butyllithium followed by the reaction with halosilanes proceeded to afford the corresponding 3-silyl substituted thiophenes 1 in good yields. The chemical polymerization of the resulting 1 did not work well. However, the electropolymerization of 3-silylthiophenes 1a and 1b provided the corresponding polymers 5a and 5b with head-to-tail regioregularity. The cyclic voltammogram of the resulting polymers 5a and 5b indicated both n- and p-doping properties.     

Conductance of nano-systems with interactions coupled via conduction electrons: effect of indirect exchange interactions

A nano-system in which electrons interact and in contact with Fermi leads gives rise to an effective one-body scattering which depends on the presence of other scatterers in the attached leads. This non local effect is a pure many-body effect that one neglects when one takes non interacting models for describing quantum transport. This enhances the non-local character of the quantum conductance by exchange interactions of a type similar to the RKKY-interaction between local magnetic moments. A theoretical study of this effect is given assuming the Hartree-Fock approximation for spinless fermions of Fermi momentum k_F in an infinite chain embedding two scatterers separated by a segment of length L_c. The fermions interact only inside the two scatterers. The dependence of one scatterer onto the other exhibits oscillations of period π/k_F which decay as 1/L_c and which are suppressed when L_c exceeds the thermal length L_T. The analytical results given by the Hartree-Fock approximation are compared with exact numerical results obtained with the embedding method and the DMRG algorithm.