In this paper, we report on the identification of batches of analgesic paracetamol (acetaminophen) tablets using nitrogen-14 nuclear quadrupole resonance spectroscopy ((14)N NQR). The high sensitivity of NQR to the electron charge distribution surrounding the quadrupolar nucleus enables the unique characterization of the crystal structure of the material. Two hypothesis were tested on batches o...

The structure of the condensed bromocadmate anions in [C(NH2)3]Cd2Br5 (1) and [H2NNH3]3CdBr5 (2) were studied at room temperature by X-ray diffraction. (1) crystallizes with double-chains bridged by Br atoms (orthorhombic, Pmmn, Z = 2, a = 1394.0(5), b = 394.5(1), c = 1086.9(5) pm). This chain structure was not described previously. (1) shows three 8 'Br NQR lines at temperatures between 77 and...

The influence of the rf field inhomogeneity on the NQR nutation spectra of spin / = 3/2 nuclei in powder samples is investigated. To eliminate the rf field inhomogeneity effects, a method of reconstruction of the NQR nutation spectra, based on finding the deconvolution of the Fourier nutation spectrum with a function of the rf field distribution, is used. The method is successfully demonstrated...

The crystal structure of (Ph 3 P) 2 AgOC 6 H 2 Cl 3 (I) is reported along with the syntheses and C1 and 6 Cu NQR spectra of I and several related silver (I) and copper (I) 2,6-diand 2,4,6-trichlorophenolates containing phosphines, phosphites, and pyridine as co-ligands. I crystallizes in space group P2 Jc with a= 16.692(4) Ä, b= 17.942 (4) A, c = 12.857 (3) Ä, /? = 97.60 (1)°, F = 3816.68 Ä, an...

The sodium ion-translocating NADH:quinone oxidoreductase (Na(+)-NQR) from the human pathogen Vibrio cholerae is a respiratory membrane protein complex that couples the oxidation of NADH to the transport of Na(+) across the bacterial membrane. The Na(+)-NQR comprises the six subunits NqrABCDEF, but the stoichiometry and arrangement of these subunits are unknown. Redox-active cofactors are FAD an...

The effects of off-resonance irradiation in nutation NQR experiments are demonstrated both experimentally and theoretically. The theoretical description of the off-resonance effects in 2D nutation NQR spectroscopy is given, and general exact formulas for the asymmetry parameter are obtained. It is shown that the outcome of the off-resonance nutation experiments depends on the data acquisition p...

Nuclear quadrupole resonance (NQR) is a solid-state radio frequency spectroscopic technique that can be used to detect the presence of quadrupolar nuclei, that are prevalent in many narcotics, drugs, and explosive materials. Similar to other modern spectroscopic techniques, such as nuclear magnetic resonance, and Raman spectroscopy, NQR also relies heavily on statistical signal processing syste...

We report pure zero field nuclear magnetic resonance (NQR) measurements on the optimally doped three layer highTc-compounds HgBaCaCuO and HgBaCaCuO(F) with Tc 1⁄4 134 K. Above Tc two Cu NQR line pairs are observed in the spectra corresponding to the two inequivalent Cu lattice sites. Below Tc the Cu NQR spectra show additional lines leading to the extreme broadened Cu NQR spectra at 4.2 K well ...

The Na+-translocating NADH:quinone oxidoreductase (Na+-NQR) from Vibrio cholerae is a membrane-bound, respiratory Na+ pump. Its NqrF subunit contains one FAD and a [2Fe-2S] cluster and catalyzes the initial oxidation of NADH. A soluble variant of NqrF lacking its hydrophobic, N-terminal helix (NqrF') was produced in V. cholerae wild type and nqr deletion strain. Under identical conditions of gr...