The splittings observed in the 209Bi nuclear quadrupole resonances of a-Bi?0 3, in zero magnetic field, follow the typical pattern of a Zeeman perturbed NQR spectrum. The lineshapes in Bi30 4Br also indicate a poorly resolved splitting that points to the presence of an internal magnetic field in the order of 200 G. This exceeds notably the dipole nuclear magnetic fields (about several G), but i...

By single crystal C1-NQR Zeeman spectroscopy, the five independent C1 nuclear quadrupole coupling tensors in a-parachloral, (Cl3CCHO)3, have been studied at 24 ± 2 °C. The directions of the electric field gradient (EFG) tensor components have been determined. The principal axes are within ± 0.8° parallel to the C-Cl bond directions found by X-ray diffraction. Very small asymmetry parameters in ...

The detection of explosives is a challenging topic. The nitrogen-14 nuclear quadrupole resonance technique exploits the transitions between the energy levels split by the quadrupole interaction to detect the presence of explosives. It is a very promising new technique owing to its unambiguous detection and identification of explosives with low false alarm, high sensitivity and fast detection. T...

Two-dimensional exchange Cl nuclear quadrupole resonance spectroscopy for studies of the CCl3-group reorientation processes in hexachloroethane and chloral hydrate has been applied. Experimental results were interpreted on the basis of the 2D exchange nuclear quadrupole resonance theory, which takes into account the off-resonance irradiation. It has been demonstrated that 2D nuclear quadrupole ...

The quadrupole coupling constants in solids usually depend on temperature (see f.e. Ref. [1 — 8 ]). This can be explained by the change of vibration amplitudes of molecules, but the influence of the volume expansion on the electric field gradient has also to be taken into account [4], For 185Re and 187Re in some peirhenates NQR measurements have been reported [9 — 16]. With the exception of NH ...

2,3,4,4-Tetrachloro-l-oxo-l,4-dihydronaphthaline, ß-TKN, crystallizes in the orthorhombic space group D ^ P n m a with Z = 4, and the C1 N Q R spectrum consists of three lines with an intensity ratio of 2:1:1. The crystal structure of 2,2,3,4-tetrachloro-l-oxo-l,2-dihydronaphthaline, a-TKN, is described in literature as belonging to the polar space group C ^ P ^ with Z = 2. In contradiction to ...

Spectroscopic techniques allow for studies of materials and organisms on the atomic and molecular level. Examples of such techniques are nuclear magnetic resonance (NMR) spec-troscopy—one of the principal techniques to obtain physical, chemical, electronic and structural information about molecules—and magnetic resonance imaging (MRI)—an important medical imaging technique for, e.g., visualizat...