6 research outputs found

    NMR investigations into the reactivity of drug acyl glucuronides

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    FISCALIS Project Group - Analysis and Characterisation of Alcoholic Products (ACAP)

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    The purpose of the ACAP working group (composed of JRC, TAXUD and 11 Member States Custom Laboratories) was to provide scientific support for the resolution of the issue of divergent classifications of alcoholic beverages for excise duties, whether by providing objective criteria for classification, or providing sound scientific information for revision of legislation. In particular, there is a need for analytical methods allowing for the differentiation between "fermented" and "distilled" ("non-fermented") beverages and for the detection of ethanol addition. At present there is no commonly agreed solution of these problems which has resulted in the Customs Laboratories of the Member States developing their own particular approaches to deal with these issues. This can lead to divergent classification between Member States and consequent problems both for administrations and the trade. Two complementary pathways of investigation have been examined in this study: NMR fingerprinting and "classical analysis", both handled by multivariate data analysis. It is the findings of this study that it is likely to be extremely difficult or even impossible to create workable ¿general¿ models based on analytical methods. Unfortunately, the difficulties are the greatest precisely with those categories that are the most problematic for excise classification purposes. Even if an analytical model was eventually developed it is likely to need to be an extremely complex mechanism in order to take account of the broad range of beverages, and diverse chemical characteristics, of products that fall within the problem categories ("other fermented beverages" etc.). On the issue of 'added alcohol' the findings reinforce that is not plausible to ascertain the amounts by a scientific study of the finished product only. The case-to-case approach to classification applied by Member States remains therefore the only possible approach in the context of the current legislation.JRC.I.5-Physical and chemical exposure

    Rare Nuclearities and Unprecedented Structural Motifs in Manganese Cluster Chemistry from the Combined Use of Di-2-Pyridyl Ketone with Selected Diols

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    The combined use of di-2-pyridyl ketone ((py)2CO) with various diols in Mn cluster chemistry has afforded five new compounds, namely, [Mn11O2(OH)2{(py)2CO2}5(pd)(MeCO2)3(N3)3(NO3)2(DMF)4](NO3)∙2DMF∙H2O (1∙2DMF∙H2O), [Mn11O2(OH)2{(py)2CO2}5(mpd)(MeCO2)3(N3)3(NO3)2(DMF)4](NO3) (2), [Mn12O4(OH)2{(py)2CO2}4(mpd)2(Me3CCO2)4(NO3)4(H2O)6](NO3)2∙2MeCN (3∙2MeCN), [Mn4(OMe)2{(py)2C(OMe)O}2(2-hp)2(NO3)2(DMF)2] (4), and [Mn7{(py)2CO2}4(2-hp)4(NO3)2(DMF)2](ClO4)∙DMF (5∙DMF) ((py)2CO22− and (py)2C(OMe)O− = gem-diol and hemiketal derivatives of di-2-pyridyl ketone, pdH2 = 1,3-propanediol, mpdH2 = 2-metly-1,3-propanediol, 2-hpH2 = 2-(hydroxymethyl)phenol). Complexes 1 and 2 are isostructural, possessing an asymmetric [MnIII5MnII6(μ4-O)(μ3-O)(μ3-OH)(μ-OH)(μ3-OR)2(μ-OR)10(μ-N3)]8+ core. Compound 3 is based on a multilayer [MnIII8MnII4(μ4-O)2(μ3-O)2(μ3-OH)2(μ-OR)12]10+ core, while complex 4 comprises a defective dicubane core. The crystal structure of 5 reveals that it is based on an unusual non-planar [MnIII5MnII2(μ-OR)12]7+ core with a serpentine-like topology. Direct current (dc) magnetic susceptibility studies revealed the presence of dominant antiferromagnetic exchange interactions in complex 3, while ferromagnetic coupling between the Mn ions was detected in the case of compound 5. Fitting of the magnetic data for complex 4 revealed weak antiferromagnetic interactions along the peripheral MnII∙∙∙MnIII ions (Jwb = −0.33 (1) cm−1) and ferromagnetic interactions between the central MnIII∙∙∙MnIII ions (Jbb = 6.28 (1) cm−1)
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