No abstract available

[en] The results of the measurement of the rotational Raman spectra of isotopically pure species ⁷⁹Br₂ and ⁸¹Br₂ were reported. It is shown that the pure rotational Raman spectra of fairly heavy linear molecules can be obtained directly with photoelectric recording

[en] ⁸¹Br NQR frequencies and differential scanning calorimetry (DSC) were measured as a function of temperature. [NH₃(CH₂)₄ NH₃]CdBr₄ (1) and [NH₃(CH₂)₅NH₃]CdBr₄ (2) showed a doublet and quartet ⁸¹Br NQR spectrum, respectively. [NH₃(CH₂)₅NH₃]ZnBr₄ (3) and [NH₃(CH₂)₆NH₃]ZnBr₄ (4) exhibited a four-line ⁸¹Br NQR spectrum. From the NQR results, it is inferred that (1) and (2) consist of infinite two-dimensional sheets of corner-sharing CdBr₆ octahedra, whereas (3) and (4) have isolated [ZnBr₄]^2- tetrahedra. All of the crystals except (1) showed at least one structural phase transition above 380 K.

No abstract available

No abstract available

[en] The D → X transition is studied for both natural Br₂, using 1576-A radiation from an F₂ laser to excite thee fluorescence. The characteristic interference structure at the long-wavelength end of the spectrum is found to be much more sensitive to changes in isotopic mass than to changes in the vibrational and rotational quantum numbers, when all three represent comparable changes in the energy of the excited state. These dependences are consistent with predictions from semiclassical theory

[en] The crystal structure of the low-temperature phase (LTP) of the title compound was determined at 220 K (monoclinic, P2_1/c). The 4-aminopyridinium cations (4-NH₂C₅H₄NH⁺) were found to be ordered in LTP, while being severely disordered in the room-temperature phase (monoclinic, C2/c). The tetrabromoantimonate anions (SbBr₄^-) were incorporated into the infinite polyanion chains of irregular SbBr₆ octahedra with two-edges sharing. The trans-Br-Sb-Br moiety in the SbBr₄^- anion was approximately symmetric differing from the asymmetric Br-Sb···Br moiety found in LTP of pyridinium tetrabromoantimonate (3). The N-H moieties in both of the pyridine ring and the amino (-NH₂) group participate in the formation of N-H···Br hydrogen bonds. It was shown that the ⁸¹Br NQR spectrum of LTP is closely related to the anion structure and the hydrogen bonds. The distinctive anion structures, as well as the different types of phase transitions, exhibited by the PyH and 4-APyH salts, seemed to be attributable to the difference in the hydrogen bond scheme between them. (author)

[en] As part of the ongoing sewerage rehabilitation and expansion program of the Manila Waterworks and Sewerage System (MWSS), flow conditions within existing sewerage systems of Metro Manila were evaluated. A radioactive tracer solution was used to measure the flow of sewege through different sewer lines and lift stations of the MWSS under gravity flow and various pumping conditions. Forty millicuries of Bromine-82 was introduced at a constant rate selected injection points and samples for radioactivity determination were taken downstream. With this dilution method, also known as tracer rate balance method, the rates of flow of sewege in some sewege lines and lift stations were obtained. The low relative deviations (5.0%) are indicative of the very good precision of the measurements. (author)

[en] The magnetic d+pole moments of the lower states of ''aligned'' rotational bands with j(>=)9/2 for the series of odd nuclei: sup(71,73,75,77)As, ⁸¹Br, sup(67,69,71,73)Ge, sup(107,109,111,113,115)Cd, sup(193,195,197,199)Hg are calculated within the framework of the angular momenta coupling scheme (AMCS). The same deformation parameter delta=0.15 was chosen for all the nuclei. The magnetic dipole moments of the isomeric states of the nuclei in question w+th γ(>=)9/2 are described well within the framework of the selected model. On this basis it can be assumed that the properties of these states are essentially determined by the Coriolis forces and that these states are deformed with the deformation parameter of approximately 0.15. ''Aligned'' rotational bands have so far been found only for Hg, sup(107,109)Cd, sup(71,73)Ge, and ⁶⁹As isotopes

[en] Bromine-81 magnetic resonance measurements are used to detect the formation of bromide-organomercurial-protein complexes. When an organomercurial compound is placed in a NaBr solution of various proteins, the bromine-81 magnetic resonance line broadens. This phenomenon can only be observed if the mercury coordination number is at least 3 with the sites being occupied by the organic moiety, the protein, and a bromide. Under these conditions quadrupolar relaxation becomes more efficient as bromide exchanges between the bound and the free states. The complexes are characterized by determining their correlation times at the binding site(s) (segmental motion) as well as the bromide ion-exchange rates. A possible fourth coordination site on mercury can be detected by adding DMSO to a NaBr solution containing the bromide-organomercury-protein complex. 22 refs., 3 figs., 1 tab