Determination of electrical and solar cell parameters of FTO/CuPc/Al Schottky devices

A Schottky structure is fabricated using CuPc sandwiched between fluorinated tin oxide (FTO) and aluminium electrodes. The electrical properties of the device are measured at room temperature. Permittivity of the device is calculated from capacitance measurements. The saturation current density, , diode ideality factor, n=3.02 and barrier height, are determined for the Schottky juction. Reverse bias versus is interpreted in terms of Schottky emission. Solar cell parameters are determined from the J-V characteristics. Power conversion efficiency, η of 0.0024% is obtained for the cell. Band gap energy of the material is determined from UV-visible absorption spectrum.     

Extending the biocatalytic scope of regiocomplementary flavin-dependent halogenase enzymes

Flavin-dependent halogenases are potentially valuable biocatalysts for the regioselective halogenation of aromatic compounds. These enzymes, utilising benign inorganic halides, offer potential advantages over traditional non-enzymatic halogenation chemistry that often lacks regiocontrol and requires deleterious reagents. Here we extend the biocatalytic repertoire of the tryptophan halogenases, demonstrating how these enzymes can halogenate a range of alternative aryl substrates. Using structure guided mutagenesis we also show that it is possible to alter the regioselectivity as well as increase the activity of the halogenases with non-native substrates including anthranilic acid; an important intermediate in the synthesis and biosynthesis of pharmaceuticals and other valuable products.     

Improvement of some pharmaceutical properties of mycophenolate mofetil (MMF) by para sulphonatocalix[4]resorcinarene inclusion complex

As a part of our investigations to unfold the chemistry of calixresorcinarene, we have focused on the formation of inclusion complex of a poorly soluble (43 μg ml^?1 at pH 7) drug mycophenolate mofetil (MMF) an immunosuppressive agent and an inosine monophosphate dehydrogenase (IMPDH) inhibitor with para sulphonatocalix[4]resorcinarene (PSC4R). The complete complexation of the drug was achieved after 48 h of stirring with para sulphonatocalix[4]resorcinarene(PSC[4]R) in water and evaporation of water yield the solid complex. The interaction between para sulphonatocalix[4]resorcinarene(PSC[4]R) and MMF in solid state inclusion complexes was accomplished by aqueous phase solubility studies, Thermal Analysis, HPLC, PXRD, FT-IR, and UV–Vis spectroscopy. The results of the phase solubility experiments are in good conformity to signify the formation of 2:1 PSC4R: MMF complexes. The purpose of this study was to enhance solubility and resulting in high dissolution rate and bioavailability of this essentially water insoluble drug. The results of the in vivo study shows that there is a remarkable change in the toxicity of the pure drug MMF and complex did not produce any mortality up to 2200 mg kg^?1.     

Polarographic reduction of pyruvic acid

The application of Delahay’s theory of kinetic polarographic currents as applied to the reduction of pyruvic acid has been examined. It is shown that the agreement between Delahay’s theory and the available data is more satisfactory, if one assumes that the current is controlled by the rate of the reaction between pyruvate ion and water molecule forming pyruvic acid and hydroxyl ion, than when one assumes the mechanism suggested by the earlier workers involving the rate of reaction between pyruvate ion and hydrogen-ion, both from the point of view of the magnitude of the diffusion current as well as its pH dependence. The results give an indication of the latter reaction being sluggish due to the activation energy requirements.     

Abbeugung des Lichts durch kolloide Lösungen

Ohne Zusammenfassung übersetzt von A. Siehr (Leipzig). Herrn Prof. H. E. Watson, D. Sc., F. I. C., M. I. Chem. E., m?chte ich an dieser Stelle meinen herzlichsten Dank für seine wertvolle Hilfe und Anleitung bei der Durchführung dieser Arbeit aussprechen.     

The multicomponent reaction of dimethoxycarbene, dimethyl butynedioate and electrophilic styrenes: an unprecedented synthesis of highly substituted cyclopentenone acetals

The zwitterionic species generated by the addition of dimethoxycarbene to dimethyl butynedioate is trapped by arylidenemalononitrile to yield cyclopentenone derivatives.     

Ortho-tellurated derivatives of some arylamines and imines

A range of novel bi-, tri- and multidentate organotellurium ligands containing Te and N donor atoms and their derivatives have been synthesised. The synthetic strategy involves telluration of orthochelating, monoanionic substrates derived from the following arylamines: N,N-dimethylbenzylamine, (S)-(-)-N,Ndimethyl-1-phenethylamine, N,N-dimethylnaphthylamine, (N,N-di-methylaminomethy l) ferrocene, tricarbony1(N, N-dimethylbenzenemethanamine) chromium and 2-(3-thienyl)-pyridine. In addition novel chiral hybrid Schiff base ligands have been prepared by the condensation reaction of bis(o-formylphenyl) telluride ando-butyltellurobenzaldehyde with (R)-(+)-l-phenethylamine and (1R, 2S)-(-)-norephedrine.     

Branched Carbon Nanotube Junctions Predicted by Computational Nanotechnology and Fabricated through Nanowelding

Examples of progress in fabricating branched multi-terminal multi-wall and single-wall carbon nanotube junctions as predicted by nanotechnology simulations, using template growth and nanowelding techniques, respectively, have been briefly reviewed in this report. It is argued that similar general progress in computational nanotechnology-driven fabrication of applications in other nanomaterials such as nanotubes, fullerenes, nanowires, quantum dots, DNA molecules, and nanoparticle-based systems and devices are also feasible. This is because, at nanometer length scale, system sizes have shrunk sufficiently small such that it is feasible to simulate the structural, stability, and physical and chemical characteristics with very high accuracy predictive simulations.     

A determinant of symmetric forms

Let Δ(α + β) = |H_λ2?r+1| where H_r is the complete symmetric function in (α₁ + β₁), (α₂ + β₂), …, (α_n + β_n). It is proved that Δ(α + β) ? Δ(α) + Δ(β). This inequality is generalised for certain symmetric functions defined by Littlewood. Let . Then we prove that Ω(α + β) ? Ω(α) + Ω(β). Here λ₁, λ₂, λ₃, …, λ_n is a partition such that λ_n > λ_n?1 > ··· > λ₂ > λ₁.