Evaluation of energy transfer in perylene-cored anthracene dendrimers

Quantitative evaluation of F?rster-type fluorescence resonance energy transfer (FRET) was undertaken by statistical investigations on perylene-cored anthracene dendrimers.     

Evaluation of effective thermal conductivity of fireworks compositions

Effective thermal conductivity of fireworks raw materials and their mixture have been measured by the temperature modulated DSC and the hot wire method, in order to predict spontaneous ignition properties precisely. As a result, an excellent linear correlation has been obtained between the density and the λ_e by the TMDSC method. Moreover, the low-density data by the hot wire method lie on the extrapolated point of the linear correlation. Thus, the λ_e within the ordinary limit of fireworks composition can be measured by the TMDSC method. Krupiczka’s estimation method shows a good agreement with the experimental values.     

Immunoassay for acetamiprid detection: application to residue analysis and comparison with liquid chromatography

This work describes the fundamental ability of a commercial ELISA to determine acetamiprid and the application of the ELISA to residue analysis in fruit and vegetable samples. The ELISA exhibited satisfactory sensitivity (I ₅₀ 0.6 ng/g; limit of detection 0.053 ng/g) and a high selectivity for acetamiprid versus other neonicotinoid analogs (thiacloprid amide). Methanol, which influenced the sensitivity of the ELISA the least, was selected as the extractant for the ELISA analysis. Simple dilution of sample extracts with water eliminated matrix interferences. Average recoveries from the acetamiprid-spiked agricultural samples were >95% using a simple extraction method. Analytical results obtained from the ELISA were comparable to those obtained from the reference HPLC method (r>0.99). The ELISA applied to the residue analysis of acetamiprid in agricultural products is a rapid, simple, and cost-effective method, and could be successfully applied to the detection of acetamiprid before the distribution of produce.     

Densities and Viscosities of Tris(acetylacetonato)cobalt(III) Complex Solutions in Various Solvents

The densities and the viscosities of tris(acetylacetonato)cobalt(III) solutions in acetonitrile, dichloromethane, chloroform, tetrachloromethane, benzene, toluene, ethylbenzene, and p-xylene were measured in the dilute concentration regions at several temperatures ranging from 278 to 313 K under ambient pressure. The partial molar volumes of the solvents and solute were calculated. They are independent of concentration and increase slightly as the temperature increases. The viscosity A- and B-coefficients of the Jones-Dole equation were obtained. The A-coefficients were found to be zero within experimental error. The B-coefficients are positive and decrease as the temperature increases. Thermodynamic quantities of activation for viscous flow were calculated on the basis of Eyring’s viscosity equation. From the quantities obtained in this study, along with some information from the literature, it is suggested that structure-making interactions occur between the segments of the complex and the solvent molecules. These interactions include electrostatic interactions between the local charge on the complex and the dipole moment of the solvent in solutions of acetonitrile and dichloromethane, interlocking packing interactions along C ₃-axis of the complex with solvent in solutions of chloroform and tetrachloromethane, and π-electron interactions between the chelate ring of the complex and the solvent in solutions of benzene, toluene, ethylbenzene, and p-xylene.     

Forcings with the countable chain condition and the covering number of the Marczewski ideal

We prove that the covering number of the Marczewski ideal is equal to ₁ in the extension with the iteration of Hechler forcing.     

Synthesis and properties of highly fluorescent indolizino[3,4,5-ab]isoindoles

We report here the synthesis, X-ray structures, optical and electrochemical properties, fabrication of light-emitting devices, and density functional calculations for indolizino[3,4,5-ab]isoindole (INI) derivatives. Strongly luminescent heterocycles based on the INI unit were synthesized by 1,3-dipolar cycloaddition reactions between pyrido[2,1-a]isoindole (PIS) and acetylene or ethylene derivatives. They are indolizino[3,4,5-ab]isoindoles 2-9 and 14-15, benzo[1',2'-1,2]indolizino[3,4,5-ab]isoindoles 10, pyridazino[4',5':1,2]indolizino[3,4,5-ab]isoindoles 12-13, and 2,3-hydropyridazino[4',5':1,2]indolizino[3,4,5-ab]isoindole-1,4-dione 11. The relative luminescence quantum yield can be as high as 90%. Their reduction and oxidation potentials and high luminescence can make these heterocycles possible alternatives to tris(8-hydroxyquinolinato)aluminum (Alq(3)). The brightness of the light-emitting device reached as high as 10(4) cd/m(2) and indolizino[3,4,5-ab]isoindole 3 emits beautifully blue light. The X-ray crystal structures of INI derivatives were obtained for the first time. The geometries obtained from X-ray data and density functional theory calculations shed more light on an interesting formally antiaromatic 16pi system, which is divided into 10pi and 6pi aromatic systems. We also report a relatively easy protonation of INI, which occurs at a carbon, rather than nitrogen atom.     

Cyclophane porphyrins and their metal complexes: Biomimetic study on receptor site of hemoprotein oxygen binding

A new symmetric porphyrin, 7,8,17,18-tetraethyl-3,13-dimethylporphyrin-2, 12-dipropionic acid and its derivatives were synthesized by the a,c-biladiene route. Condensation of the dipropionic acid with diamine, [H₂N(CH₂)_nNH₂, n= 6,7,8,9,10,12, and14], afforded the corresponding cyclophane porphyrins. The bridged groups were characterized by the ¹H-NMR spectra of their zinc complexes. The spin state of the Fe(III) complexes of the cyclophane porphyrins was investigated by changing the size of the bridged chain or size of axial ligand. The cyclophane-porphyrinato (III) perchlorate complexes in a mixture of MeOH and CHCl₃, with 4-benzylpyridine provide a model for methemoproteins. Steric constraint between an axial ligand and the bridge group, [-CH₂CH₂CONH(CH₂)_nNHCOCH₂CH₂]at the bridged face determines the ratio of the penta- and hexa-coordinated ferric complexes. The rate of O-binding to the Co(II) cyclophane porphyrins is mar present result indicates that removal of a solvent molecule or sixth axial ligand from the near proximity of the Co(II) complex increases the rate of O- binding.     

Synthesis and structural and electronic properties of the diacetylene- and ethylene-groups connected octaethylporphyrin(Ni) tetramer

The tetramer of octaethylporphyrin nickel complex [OEP(Ni)], connected with diacetylene and ethylene linkages, was synthesized. Its structural and electronic properties were studied, proving that two constituents of the diacetylene-group connected OEP(Ni) dimer face to each other in s-cis conformation about the ethylene linkage but not so closely as to induce a transannular π-electronic interaction between them.