NQR (nuclear quadrupole resonance) spectroscopy is potentially one of the best ways of characterizing the bonding of metal cations such as zirconocene cations and Ag to halogen donor atoms in weakly coordinating anions and neutral ligands such as halocarbons. Known coordination of organoiodine atoms to silver ions was studied by 1 NQR spectroscopy in [Ag(p-C<sH4I2)](P02F2), [Ag(o-C 6 H 4 I 2 ) ...

Cl NQR measurements revealed two phase transitions at 14.5 K and 70 K in NH4ICl4. By deuteration of the ammonium ions, the respective transition temperature increased to 27 K and 74 K. In the lowest-temperature phase of NH4ICl4, by the deuteration a remarkable change of the temperature dependence of the Cl NQR frequencies was observed. The NQR spin-lattice relaxation-time minimum, ascribable to...

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 ...

The *H N M R spin-lattice relaxation time 7 \ , C1 NQR frequency VQ, and C1 NQR spin-lattice relaxation time 7 \ Q of [ Z n ( H 2 0 ) 6 ] [SnCl6] (zinc hexachlorostannate(IV) hexahydrate) have been measured at temperatures between 77 and 350 K. The NQR spin echo signal with Vq— 15.689 MHz at 77 K showed a positive temperature coefficient attributable to O H C l type H-bonds in the crystal. vQ a...

OBJECTIVE To determine whether oltipraz (4-methyl-5-pyrazinyl-3H-1,2-dithiole-3-thione) protects against oxidative injury in cultured human retinal pigment epithelial (hRPE) cells. METHODS Primary cultured hRPE cells were incubated with various concentrations of oltipraz followed by treatment with the chemical oxidant tert-butylhydroperoxide (tBH). Cell viability was assessed by release of la...

NMR, NQR, powder X-ray diffraction, DTA and AC conductivity were measured in RMBr4 (R = Ag, Cu; M = Al, Ga) and RM2Br7 (R = Li, Ag; M = Al, Ga). In RMBr4, the activation energy of Cu diffusion was evaluated fromCu NMR and was in good agreement with that fromBr NQR. In CuAlBr4, the e Qq/h value of Cu NMR and the value of Al NMR changed linearly with decreasing temperature, although the eQq=h val...

Crystalline stanous chloride dihydrate (SCD), more descriptively named dichloroaquatin(II) monohy­ drate SnCl2(OH2) • H20 [1, 2], is not a very stable compound. The vapour pressure of its crystal water is appreciable already at room temperature. If the com­ pound is stored in a dry atmosphere or under vacuum it quickly loses water and becomes highly reactive at its surface. One of the usual met...

The purpose of this report is to describe what progress was made in defining and explaining the phenomenon of NQR and to stress some functional roles of this type of release, as based on our own data and other observations.