Crystal structure of potassium trifluoro(2-methyl-1,3-dithiano)borate, K(C5H9BF3S2)

C5H9BF3KS2, triclinic, P (1) over bar (no. 2), a = 11.9238(5) angstrom, b = 13.6060(5) angstrom, c = 14.0280(3) angstrom, alpha = 114.995(2)degrees, beta = 92.035(2)degrees, gamma = 92.390(2)degrees, V = 2057.4 angstrom(3), Z = 8, R-gt(F) = 0.049, wR(ref)(F-2) = 0.117, T = 296 K.

Crystal structure of 1,1,3-trimethyl-2-(2-(2,2,6-trimethyl-cyclohexyl)ethyl) cyclohexane, C20H34

C20H34, monoclinic, P12(1)/n1 (no. 14), a = 10.647(l) angstrom, b = 6.6844(9) angstrom, c = 11.723(1) angstrom, beta = 99.75(1)degrees, V = 822.3 angstrom(3) Z = 2, R-gt(F) = 0.043, wR(ref)(F-2) = 0.110, T = 93 K.

THE PHO-2A MUTANT OF NEUROSPORA-CRASSA WHICH IS DEFICIENT IN PI-REPRESSIBLE ALKALINE-PHOSPHATASE (EC 3.1.3.1) IS ALSO DEFECTIVE IN PI-REPRESSIBLE ACID-PHOSPHATASE (EC 3.1.3.2)

1. The mycelial Pi-repressible acid phosphatase presented p-nitrophenylphosphatase activity with negative cooperativity and Michaelian behavior when synthesized by the wild-type and pho-2A mutant strains of Neurospora crassa, respectively.2. The major acid phosphatase present in cell extracts of the pho-2A mutant of N. crassa grown in low Pi medium is more thermolabile (t1/2 = 4 min at 54-degrees-C, pH 5.4) than that of the wild strain (stable for at least 80 min at 54-degrees-C, pH 5.4).3. The pho-2A mutant of N. crassa secreted a more thermolabile acid phosphatase (t1/2 = 30 min at 50-degrees-C, pH 5.4) than the wild strain (t1/2 of at least 80 min at 50-degrees-C, pH 5.4).4. The pho-2A mutant of N. crassa synthesized a more thermolabile acid phosphatase (t1/2 = 37 min at 54-degrees-C, pH 5.4) than the wild strain in high Pi medium (t1/2 = 14 min al 54-degrees-C, pH 5.4).5. The pleiotropic nature of the pho-2 locus and its possible involvement in the mechanism of phosphatase secretion by N. crassa are proposed.

Determination of absolute configuration of 1,3-diols by the modified Mosher's method using their di-MTPA esters

1,3-Diols are frequently involved in biologically important compounds and, therefore, determination of the stereochemistry of these structural elements, in particular those in acyclic systems, has been one of the focuses of attention in natural products chemistry. The modified Mosher's method, commonly used for the determination of the absolute configuration of secondary alcohols, was applied to determine the absolute configuration of 1,3-diols with their di-MTPA esters. Several epimeric pairs of syn- and anti-1,3-diols with known absolute configurations were converted to the corresponding di-MTPA esters and the Delta delta values were then calculated. For the acyclic syn-1,3-diols, the Delta delta values were systematically arranged as predicted from the basic concept of the modified Mosher's method, demonstrating that the method is valid for these compounds. In contrast, the Delta delta values were irregularly arranged for the acyclic anti-1,3-diols and, accordingly, this method is not valid for these cases. These results are complementary to those of the previously reported CD exciton chirality method and, hence, the combined use of the modified Mosher's method and the CD exciton chirality method can determine the absolute configuration of the acyclic 1,3-diols. Also, this method is successfully applicable to cyclic 1,3-diols irrespective of their relative stereochemistry. (C) 2002 Wiley-lass, Inc.

3D hydrogen-bonded network built from copper(II) complexes of 1,3-propanediamine

The reaction of Cu(NO3)(2).3H(2)O with 1,3-propanediamine (pn), in the presence of NaN3, afforded a 1:1 co-crystal formed by [Cu(NO3)(2)(pn)(2)] and [Cu(N-3)(NO3)(pn)(2)] (1 and 2), which were characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction. In both compounds, the copper(II) centers are in a distorted octahedral environment, formed by four N atoms of two bidentate pn ligands in the basal plane, whereas the axial bonds are formed by two O atoms from the nitrate ligands in 1 and one O atom from the nitrate ligand and one N atom from the azide ion in 2. The asymmetric unit of the crystal consists of two crystallographically independent 1 and 2 complexes, which are held together in a 3D network by a series of N - H center dot center dot center dot O and N - H center dot center dot center dot N hydrogen bonds, as well C - H center dot center dot center dot O interactions. New supramolecular synthons are identified by the occurrence of two geometrically distinct molecular recognition patterns involving the NO3- ion and amino groups from pn ligands.

Nitrosyl ruthenium complexes with general formula [RuCl3,(NO)(P-P)] (P-P={PPh(2)(CH2)(n)PPh(2)},n=1-3 and {PPh(2)-CH=CH-PPh(2)}). X-ray structure of [RuCl3(NO){PPh(2)(CH2)(3)PPh(2)}]

Ruthenium(II) complexes with general formula [RuCl3(NO)(P-P)] were obtained in the solid state, where P-P = PPh(2)(CH2)(n)PPh(2) (n = 1-3) and PPh(2)-CH = CH-PPh(2). The P-31 NMR spectra of these compounds measured in CH2Cl2 showed only singlets, consistent with a fac configuration containing two equivalent phosphorus atoms, However the X-ray diffraction data show that the [RuCl3(NO){PPh(2)(CH2)(3)PPh(2)}] complex crystallizes in a met configuration, where one of the phosphorus atoms is trans to the NO group, in a slightly distorted octahedral geometry. Copyright (C) 1996 Elsevier B.V. Ltd

Crystal structure of potassium trifluoro[1,3-dithiano]borate, K(C4S2H7BF3)

C4H7BF3KS2, monoclinic, P12(1)/cl (no. 14), a = 14.7374(3) angstrom, b = 9.06121) angstrom, c = 13.5805(2) angstrom, beta = 98.964(4)degrees, V = 1791.4 angstrom(3), Z = 8, R-gt(F) = 0.029, wR(ref)(F-2) = 0.010, T = 296 K.

Electrolytic treatment of wastewater containing n-phenyl-n '-1,3-dimethylbutyl-p-phenylenediamine

This study investigated the effects of electrolytic treatment using Dimensionally Stable Anode (DSA, 70%TiO2/30%RuO2) type electrodes in simulated wastewater containing aromatic amine n-phenyl-n'-1,3-dimethylbutyl-p-phenylenediamine (Flexzone 7P). A low direct current density of 0.025 A cm(-2) was applied for periods up to 60 minutes and a 52.6% decrease in Flexzone 7P concentration was observed. Ultraviolet-visible spectra, gas chromatography, toxicity and biodegradation tests were carried out with the aim of verifying the toxic by-products that were formed. Ultraviolet-visible spectra of simulated wastewater exhibited changes in the aromatic amine's molecular structure. Additionally, based on the S. cerevisiae toxicity test, it was observed that detoxification of the wastewater occurred after 15 minutes of electrolysis. It was also observed that five minutes of treatment were sufficient to improve the biodegradation rate, determined through the respirometric Bartha method.

Kinetic properties of de-repressible alkaline phosphatase (EC 3.1.3.1) from Neurospora crassa

De-repressible alkaline phosphatase from N. crassa shows inhibition by PNP-P and a hyperbolic mixed-type inhibition by Pi. Both increasing concentrations of Pi and decreases in assay pH abolished inhibition by the substrate. Also, Pi promoted polymerization of the enzyme molecule, whose effect may account for the inhibitory behaviour shown by the enzyme in the presence of low Pi concentrations. © 1991 Rapid Communications of Oxford Ltd.

Determination of metal ions in fuel ethanol after preconcentration on 5-amino-1,3,4-thiadiazole-2-thiol modified silica gel

This work describes the synthesis and characterization of 5-amino-1,3,4-thiadiazole-2-thiol modified silica gel (SiATT), and the results of a study of the adsorption and preconcentration (in batch, and in flow using a column technique) of Cd(II), Co(II), Cu(II), Fe(III), Ni(II), Pb(II) and Zn(II) in ethanol medium. The adsorption capacities for each metal ion were (in mmol g -1): Cd(II) = 0.11, Co(II) = 0.10, Cu(II) = 0.20, Fe(III) = 0.20, Ni(II) = 0.16, Pb(II) = 0.08 and Zn(II) = 0.12. The results obtained in the flow experiments, showed a recovery of ca. 100% of the metal ions adsorbed in a column packed with 2 g of SiATT, using 5 mL of 2.0 mol L -1 HCl solution as eluent. The sorption-desorption of the metal ions made possible the development of a preconcentration method and quantification by Flame AAS of metal ions at trace level in fuel ethanol.

Preparation of a silica gel modified with 2-amino-1,3,4-thiadiazole for adsorption of metal ions and electroanalytical application

Silica gel with a specific area of 382 m2 g-1 and an average pore diameter of 60 Å was chemically modified with 2-amino-1,3,4-thiadiazole, for the purpose of selective adsorption of heavy metals ions and possible use as a chemically modified carbon paste electrode (CMCPE). The following properties of this functionalized silica gel are discussed: selective adsorption of heavy metal ions measured by batch and chromatographic column techniques, and utilization as preconcentration agent in a chemically modified carbon paste electrode (CMCPE) for determination of mercury(II). The chemical selectivity of this functional group and the selectivity of voltammetry were combined for preconcentration and determination. ©2006 Sociedade Brasileira de Química.

Crystal structure of potassium trifluoro[1,3-dithiano]borate, K(C 4S2H7BF3)

C4H7BF3KS2, monoclinic, P121/c1 (no. 14), a = 14.7374(3) Å, b = 9.0612(1) Å, c = 13.5805(2) Å, β = 98.964(4)°, V = 1791.4 Å3, Z = 8, Rgt(F) = 0.029, wRref(F2) = 0.010, T = 296 K. © by Oldenbourg Wissenschaftsverlag.

Structural control of photoluminescence of four poly(urethane-urea-co-1,3,5-triazine)s: Synthesis and characterization

A series of segmented poly(urethane-urea)s containing 1,3,5 triazine in the hard block and hexamethylene spacers in the soft block was prepared. The hard to soft segment ratio was varied systematically, to afford a series of polymers in which the chromophore concentration varied from 4.2% to 18.1%. Although triazine emission is located in the UV region, the films with higher content of the chromophore emitted a visible blue light (425 nm) when excited at the very red-edge of the absorption band. The photophysical properties of the materials were strongly dependent on the relative amount of triazine moieties along the main chain. Isolated moieties emit in copolymers with small amount of triazine groups, indicating that even though in solid state, these moieties tend to be apart. Two photophysical consequences were observed when the amount of triazine increases: there is some energy transfer process involving isolated moieties with consequent decrease of the lifetime and an additional red-edge emission attributed to aggregated lumophores. The mono-exponential decay observed for the isolated form is substituted by a bi-exponential decay of the aggregated species. The materials were not strong emitters, but since the N-containing triazine moieties are good electron transport groups, the polymers have potential application as electron transport enhancers in various applications. © 2006 Elsevier B.V. All rights reserved.

Comparison of β-1,3-glucanase production by Botryosphaeria rhodina MAMB-05 and Trichoderma harzianum Rifai and its optimization using a statistical mixture-design

Botryosphaeria rhodina MAMB-05 produced β-1,3-glucanases and botryosphaeran when grown on glucose, while Trichoderma harzianum Rifai only produced the enzyme. A comparison of long-term cultivation (300h) by B. rhodina demonstrated a correlation between the formation of botryosphaeran (48h) and its consumption (after 108h), and de-repression of β-1,3-glucanase synthesis when glucose was depleted from the nutrient medium, whereas for T. harzianum enzyme production commenced during exponential growth. Growth profiles and levels of β-1,3-glucanases produced by both fungi on botryosphaeran also differed, as well as the production of β-1,3-glucanases and β-1,6-glucanases on glucose, lactose, laminarin, botryosphaeran, lasiodiplodan, curdlan, Brewer's yeast powder and lyophilized fungal mycelium, which were dependent upon the carbon source used. A statistical mixture-design used to optimize β-1,3-glucanase production by both fungi evaluated botryosphaeran, glucose and lactose concentrations as variables. For B. rhodina, glucose and lactose promoted enzyme production at the same levels (2.30UmL -1), whereas botryosphaeran added to these substrates exerted a synergic effect favorable for β-glucanase production by T. harzianum (4.25UmL -1). © 2010 Elsevier B.V.