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Two new compounds, bis (DL-erythro-α-2-piperydylium-2,8-bis(trifluoromethyl)-4-quinolinemethanol) tetrachlorocuprate(II) tetrahydrate [LH+]2[CuCl4]2??4H2O 1 [L = mefloquine] and bis(DL-erythro-α-2-piperydylium-2,8-bis(trifluoromethyl)-4-quinolinemethanol) tetrabromocadmate (II) bis(methanol) [LH+]2[CdBr4]2?·2CH3OH 2, have been synthesized and characterized by elemental analysis, 1H-NMR and IR spectroscopy. Single-crystal X-ray diffraction analysis of 1 showed the structure to be ionic with formula unit comprising two protonated monocationic mefloquine molecules of opposite chirality, a tetrachlorocuprate (II) anion and a complement of four water molecules, disordered over several sites. The crystals are orthorhombic, space group Pnma, a = 9.6975(1) Å, b = 29.5385(3) Å, c = 15.9423(1) Å, V = 4566.67(7) Å3, Z = 4. The formula unit of compound 2 comprises two protonated monocationic mefloquine molecules, a tetrabromocadmate(II) anion and two molecules of methanol. The crystals are orthorhombic, space group Fdd2, a = 17.2185(5) Å, b = 55.456(2) Å, c = 9.5140(3) Å, V = 9084.6(5) Å3, Z = 8. The mefloquine molecule is protonated at the piperidinyl N atom and extensive hydrogen bonding occurs in both crystal structures. The conformation of the mefloquine cation in 1 and 2 is very similar to that recently observed in other salts of the drug, confirming its relevance in the context of antimalarial action. 相似文献
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Lifetime of levels up to 22+, have been measured in 78Kr and an oblate shape is assigned to the ground state using the CSM and the configuration dependent shell correction calculations.
Calculations further show that 78Kr is highly γ-soft nucleus. The experimental Q
t values coupled with theoretical calculations indicate an oblate shape for 78Kr at low spins and triaxial shape at higher spins 相似文献
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Stable isotope methods are potentially quite useful for validating natural or enhanced mineral degradation of contaminants. For this reason, a continuous flow gas chromatograph (GC), isotope ratio mass spectrometer (IRMS) has been coupled with a quadrupole mass selective detector (MSD) to allow simultaneous mass spectral and stable carbon isotope ratio data to be obtained from a single chromatographic analysis. This allows the target contaminant and any extra-cellular degradation intermediates to be both qualified and quantified. Previously acceptable limits of precision (0.3 parts per mil) are undesirable given the small fractionation observed during aerobic degradation. To further understand the fate of organic contaminants and to gain information about the metabolic degradative pathway employed by a microorganism, routine isotopic analyses on a range of analytes have been performed. Quantities of sample producing mass-44 ion beam signal (I(44)) of 2 x 10(-10) to 1 x 10(-8) A were analysed. When the IRMS was tuned for high sensitivity, ion source nonlinearities were overcome by peak height correction from an algorithm that was produced using known isotopic standards of varying concentrations. This led to sample accuracy of <0.01 per thousand and sample precision of 0.1 per thousand. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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KM Clauwaert Van Bocxlaer JF HJ Major JA Claereboudt WE Lambert Van den Eeckhout EM Van Peteghem CH De Leenheer AP 《Rapid communications in mass spectrometry : RCM》1999,13(14):1540-1545
This paper describes the investigation of the potential of a quadrupole orthogonal acceleration time-of-flight mass spectrometer (Q-TOF) equipped with an atmospheric pressure ionisation interface for quantitative measurements of small molecules separated by reversed phase liquid chromatography. To this end, the detection limits and linear dynamic range in particular were studied in an LC/MS/MS experiment using 3,4-methylenedioxymethamphetamine standards and 3,4-methylenedioxyethylamphetamine for internal standardisation. In a second phase, the experiment was repeated with real biological extracts (whole blood, serum, and vitreous humour). A calibration for 3,4-methylenedioxymethamphetamine and its metabolite 3,4-methylenedioxyamphetamine was prepared in each of these matrices again using 3,4-methylenedioxyethylamphetamine as internal standard. The resulting quantitative data were compared with those obtained by liquid chromatography with fluorescence detection for the same extracts. The Q-TOF results revealed excellent sensitivity and a linear dynamic range of nearly four decades (2-10 000 pg on-column, r(2) = 0.9998, 1/x weighting). Furthermore, all the calibration curves prepared in biological material were superimposable, LC/MS/MS and LC-fluorescence, and the quantitative results for actual samples compared very favourably. It was concluded that the Q-TOF achieves a linear dynamic range for quantitative LC/MS/MS work exceeding that of fluorescence detection and at much better absolute sensitivity. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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Lifetimes of high spin states up to {
}=22+ in the yrast positive parity bands have been measured to investigate the shape evolution with increasing spin in 72, 74Se. The Q
t values derived from these measurements indicate that prolate shape stabilizes for 72Se, while a triaxial shape develops for 74Se at higher spins. Comparison of the observed trend in Q
t with spin for 72, 74Se with that of the corresponding kryptones isotones emphasizes the stability provided by N=38 prolate shell gap even at high rotational frequency. 相似文献
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Joshua Ayoola Obaleye Mino R. Caira Adedibu C. Tella 《Journal of chemical crystallography》2007,37(10):707-712
Abstract A novel polymeric zinc(II) complex of quinine, [chlorosulphato (2-ethenyl)-4-azabicyclo[2.2.2]oct-5-ylium-(6-methoxyquinolin-4-yl)
methanol zinc(II)] has been synthesized and characterized. Single-crystal X-ray diffraction analysis of the complex (C20H25ClN2O6SZn) revealed that quinine forms a zigzag coordination polymeric complex with Zn(II) of extended chains –ZnCl–O–SO2–O–Zn–O–SO2–O–ZnCl–. The crystals are monoclinic, space group C2 with a = 20.5035(5), b = 9.7943(2), c = 11.7814(4) ?, β = 96.578(2)°, Z = 4, V = 2350.3(1) ?3. The complex exhibits a tetrahedral geometry. Each Zn(II) centre is thus coordinated to an O atom from each of two sulphate
bridges, a Cl atom and quinoline atom N(4) of the quinine moiety. The second quinuclidine nitrogen in the quinine is protonated.
In the crystal, there is linkage of two polymeric chains related by a twofold rotation axis, resulting in a bilayer. The linking
is achieved by hydrogen bonding from the quinine cation which provides two donors (–OH, N+–H), to oxygen atoms of sulphate groups which act as acceptors.
Graphical Abstract The new polymeric zinc(II) complex of quinine, [chlorosulphato (2-ethenyl)-4-azabicyclo[2.2.2]oct-5-ylium-(6-methoxy quinolin-4-yl)
methanol Zinc(II)] has been synthesized and structurally characterized The compound was characterized by IR spectroscopy,
elemental analysis and X-ray diffraction. X-ray analysis showed that quinine forms a zigzag coordination polymeric complex
with Zn(II) of extended chains –ZnCl–O–SO2–O–Zn–O–SO2–O–ZnCl–.
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