Structural characterization of the catalytically significant sites on solid catalyst surfaces is frequently tenuous because their fraction, among all sites, typically is quite low. Here we report the combined application of solid-state (13)C-cross-polarization magic angle spinning nuclear magnetic resonance ((13)C-CPMAS-NMR) spectroscopy, density functional theory (DFT), and Zr X-ray absorption...

We report high resolution 15N NMR measurements of the paraelectric to antiferroelectric phase transition (TN = 216 K) of the model hydrogen-bonded antiferroelectric NH4H2AsO4 (ADA). We specifically examined whether the NH + 4 ions undergo a displacive or an order-disorder behavior at the phase transition. High resolution NMR measurements were made on 15N-enriched single crystals, using the CPMA...

The reaction of pentaerythritol and tetraethylorthocarbonate at 260 degrees C for 12 h yields a white crystalline material that was characterized by 13C CPMAS NMR, CHN analysis, FT-IR, electron and X-ray powder diffraction, and Rietveld analysis. The white crystalline material was found to have the formula C6H8O4 and a crystal structure with a monoclinic cell [a = 9.167 A, b = 5.681 A, c = 5.88...

Using solid-state cross-polarization-magic-angle-spinning (CPMAS) C and N nuclear magnetic resonance (NMR) and 2-D double cross polarization (DCP) MAS N C NMR techniques, microbially degraded Botryococcus braunii was analyzed to study the chemical nature of organic nitrogen in the algal residue. The amide linkage, as found in protein, was observed as the major nitrogen component in 201-day-old ...

The 1 l9Sn-CPMAS-NMR spectra of the complex [(/-PrSn)pO |4(OH6)]2+ ion were recorded for two different salts having twelve and four different tin atoms in the asymmetric unit, re­ spectively. Both spectra agree very well with X-ray crystallographic predictions, and thus dem­ onstrate the great sensitivity of heavy nuclei NM R spectroscopy to subtle structural changes. Infrared spectroscopy is s...

Poultry manure (PM) chars were obtained at different temperatures and charring times. Chemical-physical characterization of the different PM chars was conducted by cross-polarization magic angle spinning (CPMAS) (13)C NMR spectroscopy and thermal analysis. CPMAS (13)C NMR spectra showed that the chemical composition of PM char is dependent on production temperature rather than on production dur...

Several studies emphasize the importance of soil organic matter characteristics in hydrophobic contaminant sorption and outline the strong dependence of sorption on organic matter aromaticity. In this study, the role of organic matter aromaticity in phenanthrene sorption was investigated using humic acids (HAs) from compost, peat, and soil that were structurally modified by bleaching, hydrolysi...

The samples of brown coal, bitumen and humic acids (HA) extracted from them are characterized by means elemental proximate analyses, FTIR, 13С NMR (CPMAS) spectroscopy gas chromatography-mass spectrometry. presence biologically active substances is detected in the samples. biological activity preparations form sodium humates saponifiable component bituminous resin investigated depending on stru...

Aminobisphosphonates, e.g., alendronate and neridronate, are a well known class of molecules used as drugs for various bone diseases. Although these molecules have been available for decades, a detailed understanding of their most important physicochemical properties under comparable conditions is lacking. In this study, ten aminobisphosphonates, H(2)N(CH2)(n)C(OH)[P(O)(OH)(2)](2) in which n = ...

Solid-state 2-D N C NMR spectroscopy was applied for the ®rst time to reveal the chemical nature of nitrogen in degraded algae. Cross peaks indicating coupling between C and N were detected only for carboxyl/amide-C and Nsubstituted-alkyl-C. Cross peaks correlating N intensity to sp-C and supporting the presence of heteroaromatic-N were not observed. The Bloch decay N NMR spectrum demonstrated ...