Estimation of the orientation of heme in cytochrome C immobilized on a carboxylate-terminated alkanethiol monolayer on a au electrode by the use of electroreflectance spectroscopy with polarized light incidence

Electroreflectance (ER) spectroscopy was used for the estimation of the orientation of heme in a horse heart cytochrome c molecule immobilized on a self-assembled monolayer of 11-mercaptoundecanoic acid on both polycrystalline gold (Au) and single crystalline Au(111) electrodes. The intensity ratio of the ER signal of p-polarized incident light against s-polarized incident light as a function of the incident angle of the light was analyzed in two ways: a doubly degenerate transition for the Soret absorption band of the heme was assumed in one, and the anisotropy of the two orthogonal transitions was taken into account in the other. The doubly degenerate model failed in the expression of the experimental data, pointing to the existence of the anisotropy. Two orthogonal in-plane linear electric dipoles with different magnitudes were assumed to be responsible for the Soret band absorption in a new analysis procedure. This enabled us to fit the experimental data closely to the simulated data. The result revealed that the heme plane is near-vertical to the electrode surface. The need of clarification of the anisotropic heme transition was invoked.     

Urea coordinated titanium trichloride Ti(III)[OC(NH)2]6Cl3: a single molecular precursor yielding highly visible light responsive TiO2 nanocrystallites

A coordination complex, Ti(III)[OC(NH2)2]6Cl3, was first synthesized via reacting hot alcoholic solutions of TiCl3 and urea, which was subsequently employed as a molecular precursor for nanocrystalline TiO2 via thermal decomposition. Fourier transform IR spectroscopy confirmed C=O-->Ti coordination bond formation, while Rietveld refinement revealed a hexagonal crystal structure (space group: Pc1) for the complex with a = b = 16.438(4) A, c = 15.423(3) A, alpha = beta = 90 degrees , gamma = 120 degrees , and V = 3608.9(13) A3. Thermal decomposition and phase evolution processes of the complex were investigated in air by combined means of elemental analysis, Fourier transform IR, differential thermal analysis/thermogravimetry, X-ray diffraction, and Raman spectroscopy. Characterizations of the resultant TiO2 powders were achieved by scanning electron microscopy, high-resolution transmission electron microscopy, the Brunauer-Emmett-Teller analysis, thermal desorption spectroscopy, and UV-vis spectroscopy. Simultaneous doping of C, N, and Cl was realized upon pyrolyzing the molecular precursor in air, leading to significantly lowered direct and indirect interband transition energies of the resultant TiO2. As a consequence, the anatase nanopowders obtained at 450 and 500 degrees C, with specific surface areas of 97.8 and 64.1 m2/g, respectively, exhibit significantly higher efficiency than Degussa P25 in the bleaching of methyl orange solution under visible light (mainly consisting two wavelengths of 405 and 436 nm at 81:100 intensity ratio) irradiation, either at a fixed weight of TiO2 loading or at a fixed surface area of the loaded TiO2 powder.     

Infrared spectra and intensities of the H2O and N2 complexes in the range of the nu1- and nu3-bands of water

The IR spectra of complexes of water with nitrogen molecules in the range of the symmetric (nu(1)) and antisymmetric (nu(3)) bands of H(2)O have been studied in helium droplets. The infrared intensities of the nu(3) and nu(1) modes of H(2)O were found to be larger by factors of 1.3 and 2, respectively, in the N(2)-H(2)O complexes. These factors are smaller than those obtained in recent theoretical calculations. The conformation of the N(2)-H(2)O complex was estimated. Spectra and IR intensities of the (N(2))(2)-H(2)O and N(2)-(H(2)O)(2) complexes were also obtained and their structures are discussed.     

Measuring technique for static electricity using focused sound

A novel method is proposed for non-contact measurement of the distribution of electrostatic charge on a surface based on scanning the sample surface with a focused high frequency acoustic beam to excite movement of the sample surface. An electric field is induced by exciting a charged film-like object, and an electric field sensor measures it instead of an electrostatic field. The focused ultrasound waves are generated by controlling individually the phase of each 285 airborne ultrasound transducers.     

An Unusual Skeletal Rearrangement in the Biosynthesis of the Sesquiterpene Trichobrasilenol from Trichoderma

The skeletons of some classes of terpenoids are unusual in that they contain a larger number of Me groups (or their biosynthetic equivalents such as olefinic methylene groups, hydroxymethyl groups, aldehydes, or carboxylic acids and their derivatives) than provided by their oligoprenyl diphosphate precursor. This is sometimes the result of an oxidative ring‐opening reaction at a terpene‐cyclase‐derived molecule containing the regular number of Me group equivalents, as observed for picrotoxan sesquiterpenes. In this study a sesquiterpene cyclase from Trichoderma spp. is described that can convert farnesyl diphosphate (FPP) directly via a remarkable skeletal rearrangement into trichobrasilenol, a new brasilane sesquiterpene with one additional Me group equivalent compared to FPP. A mechanistic hypothesis for the formation of the brasilane skeleton is supported by extensive isotopic labelling studies.     

Thermal extrusion of cellulose using hydroxypropyl methylcellulose

Cellulose - Hydroxypropyl methylcellulose (HPMC), a cellulose derivative, is highly water soluble, viscoelastic, and thermoplastic. However, the thermoplasticity of HPMC has not yet been studied in...     

Aerobic Toluene Oxidation Catalyzed by Subnano Metal Particles

Subnanocatalysts (SNCs) containing various noble metals (Cu, Ru, Rh, Pd, or Pt) with sizes of approximately 1 nm were synthesized using dendritic poly(phenylazomethine)s as a macromolecular template. These materials exhibit high catalytic performance during toluene oxidation without the use of harmful solvents or explosive oxidants, resulting in the formation of valuable organic products, including benzoic acid as the major product. In particular, Pt₁₉ SNC with a narrow particle size distribution exhibits extraordinary catalytic activity, with a turnover frequency of 3238 atom^?1 h^?1, which is 1700 times greater than that obtained by commercial Pt/C catalysts.     

Conformational analysis of N-aryl-N-(2-azulenyl)acetamides

Aromatic amides bearing 2-azulenyl group on the amide nitrogen were synthesized and their structures were investigated. The π-electron density of the N-aryl group was found to influence the cis-trans conformational preferences of these compounds in solution. X-ray crystallography revealed that the plane of the 2-azulenyl ring has a strong tendency to lie coplanar with the amide plane when the azulene group is located on the same side as the amide oxygen atom.