The influence of the cations on the condensation of the anions in the salts (A')Zn(II) Br4 and (A)2Zn(II)Br4 is studied by 81 Br NQR and X-ray crystal structure analysis. (A')Zn(II)Br4(A' = [H3N(CH2)3NH3] + ) (1) shows a phase transition at 474 K. The phase II of (1) crystallizes with isolated [ZnBrJ " tetrahedra: monoclinic P2 t/«, Z = 4, a = 1108.4 (5), b = 1096.8 (2), c = 1118.5 (6) pm, and ...

Stable crystalline 2-chlorothiophene has two glass transitions at 164 and 186 K. CI NQR measurements were carried out between 77 and 200 K. Two NQR signals with full widths of about 100 kHz at half maximum were observed in this temperature range. The spin-lattice relaxation times Ti were measured at the two peak frequencies. The activation energy obtained from the results of the T\ measurements...

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 local bonding structure in the Ge–As–Se ternary glassy system has been investigated by As nuclear quadrupole resonance (NQR) at 77 K. For the compositions with average coordination number r 1⁄4 2:2; 2:4; 2:54 the NQR measurements yield no evidence for the presence of As–As homopolar bonds. For the composition Ge2As2Se5 ( r 1⁄4 2:67) the NQR lineshape exhibits two peaks corresponding to arse...

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...

Studies of the biological chemistry of aluminium can gain significantly from the use of the long-lived isotope 26Al as a tracer, although the cost of the isotope often precludes its determination by radiochemical counting techniques. Accelerator mass spectrometry (AMS) provides an ultra-sensitive method of determination, free from isobaric interference from atomic (26Mg) or molecular species. T...

The 444 nm 2 0 (1) bands of the A 2A'-X 2A" transition of the jet-cooled HP 35Cl and HP 37Cl radicals have been studied at high resolution using the pulsed electric discharge technique with a precursor mixture of PCl3 and H2. Spectra recorded with linewidths of approximately 360 MHz revealed resolved hyperfine structure in both isotopomers arising from the excited state Fermi contact interactio...

The fully energy-damped yields from the 35Cl+12C reaction have been systematically investigated using particle-particle coincidence techniques at a 35Cl bombarding energy of ∼ 8 MeV/nucleon. The fragment-fragment correlation data show that the majority of events arises from a binary-decay process with rather large numbers of secondary light-charged particles emitted from the two excited exit fr...