AFM-Raman colocalization setup: Advanced characterization technique for polymers

The optimization of manufacturing processes and the investigation of polymer materials during their life cycle imply an extended knowledge of the physical and chemical properties of the material. To obtain colocalized chemical, morphological, and thermomechanical information on the same sample area, we have developed an innovative colocalized atomic force microscopy (AFM)-Raman setup and a sample preparation strategy using cryoultramicrotomy. The developed technique allows perfect cross-sectioning of thin membranes (10–300?µm) without embedding avoiding chemical contamination. The opened surface is characteristic of the material’s bulk properties and allows spectroscopic and near-field measurements without sample artifacts. Additionally, thin sections can be collected for complementary transmission electron microscopy.     

Preparation and X-Ray crystal structure of a Novel Nickel(II) complex with dithiocarbimate

The reaction of potassiumN-(methanesulfonyl)-dithiocarbimate, K₂[S₂C=NSO₂CH₃], with nickel(II) chloride hexahydrate, NiCl₂·6H₂O, formed the complex anion bis(N-(methanesulfonyl)-dithiocarbimate)nickelate(II), [Ni(S₂C=NSO₂CH₃)₂]^2}-, which was isolated as its tetra-n-butylammonium salt. The UV-Vis data obtained were consistent with the formation of a nickelsulfur diamagnetic planar complex. The¹H NMR and the¹³C NMR spectra showed the expected signals for then-Bu₄N⁺ cation and the dithiocarbimate moiety. The single-crystal structure analysis showed that tetra-n-butylammonium bis(N-(methanesulfonyl)-dithiocarbimate)nickelate(II), (Bu₄N)₂[Ni(S₂C=NSO₂CH₃)₂], crystallizes in the monoclinic space groupP2_l/c witha=9.3197(5),b=15.0795(8),c=17.5286(9) å,=91.262(3),V=2462.8(3) å³, andZ=2. The nickel atom is coordinated to four sulfur atoms.     

Thermal characterization of mercury(II) bis(dialkyldithiocarbamate) complexes

Summary Solid-state M-4-MeO-Bz compounds, where M stands for bivalent Mn, Co, Ni, Cu and Zn and 4-MeO-Bz is 4-methoxybenzoate, have been synthesized. Simultaneous thermogravimetry-differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy, elemental analysis and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to have information about the composition, dehydration, thermal stability and thermal decomposition of the isolated compounds.     

Lignocellulosics to biofuels: An overview of recent and relevant advances

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Quantu-design and development of a software package dedicated to k0-standardized NAA

This work shortly describes the main steps involved in the design and development of the software package Quantu, created to conduct k ₀-standardized NAA. The package comprises a database as well as two individual programs. Quantu-MCA is dedicated to (g-ray spectrum analysis and Quantu-INAA is the interface for the database administration, also dealing with k ₀-method calculations.     

Isolation and structure determination of bioactive isoflavones from callus culture of Dipteryx odorata

Crude extracts of callus and roots of Dipteryx odorata were analyzed by HPLC to detect and quantify isoflavone contents. Based on spectroscopic and X-ray crystallography data the structures of two isoflavones were elucidated as 7-hydroxy-4',6-dimethoxyisoflavone and 3',7-dihydroxy-4',6-dimethoxyisoflavone. The production of dry biomass of 7-hydroxy-4',6-dimethoxyisoflavone in cultured callus was 4.12 mg/g, approximately eleven fold higher than the amount accumulated in roots of D. odorata wild-growing plants. The 7-hydroxy-4',6-dimethoxyisoflavone was effective against glyceraldehyde-3-phosphate dehydrogenase from Trypanosoma cruzi. This is the first report on those bioactive isoflavones accumulated in callus of D. odorata.     

Bromine-substituted 1,2,3,4-tetrahydro-4-methylspiro[quinoline-2-cyclohexanes]

The bromination of 1,2,3,4-tetrahydro-4-methylspiro[quinoline-2-cyclohexane] has been carried out under various conditions. Dibromo and monobromo derivatives have been obtained; the monobromo derivatives were synthesized by cyclization of 1-allyl-1-bromophenylaminocyclohexanes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1350–1353, October, 1991.