Development of two new techniques for studying the gas phase chemistry of negative ions is reported. Collision induced dissociation (CID) of (M-1)- ions has been accomplished in a newly constructed triple stage quadrupole mass spectrometer. This instrument was assembled by adding two additional Finnigan quadrupole mass filters to a Finnigan Model 3200 CI mass spectrometer. Generation of (M-1)- ...

The Rb-NH interaction is investigated as a prototype for interactions between alkali-metal atoms and stable molecules. For spin-aligned Rb and NH that interact on a quartet surface (4A"), the interaction is relatively weak, with a well depth of 0.078 eV. However, there are also doublet surfaces of ion-pair character that are very much deeper (well depth 1.372 eV). They may be important for atom...

The Rb-NH interaction is investigated as a prototype for interactions between alkali metal atoms and stable molecules. For spin-aligned Rb and NH that interact on a quartet surface (A), the interaction is relatively weak, with a well depth of 0.078 eV. However, there are also doublet surfaces of ion-pair character that are very much deeper (well depth 1.372 eV) and may be important for atom mol...

The theory describing homonuclear indirect nuclear spin-spin coupling (J) interactions between pairs of quadrupolar nuclei is outlined and supported by numerical calculations. The expected first-order multiplets for pairs of magnetically equivalent (A2), chemically equivalent (AA'), and non-equivalent (AX) quadrupolar nuclei are given. The various spectral changeovers from one first-order multi...

Efficient method is proposed for computing thermal rate constant of recombination reaction that proceeds according to the energy transfer mechanism, when an energized molecule is formed from reactants first, and is stabilized later by collision with quencher. The mixed quantum-classical theory for the collisional energy transfer and the ro-vibrational energy flow [M. Ivanov and D. Babikov, J. C...

We present negative ion formation from collisions of neutral potassium atoms with D-ribose (C5H10O5), the sugar unit in the DNA/RNA molecule. From the negative ion time-of-flight (TOF) mass spectra, OH(-) is the main fragment detected in the collision range 50-100 eV accounting on average for 50% of the total anion yield. Prominence is also given to the rich fragmentation pattern observed with ...

For a high-quality single crystal of UPd3 we present the relevant elastic constants and ultrasonic attenuation data. In addition to the magnetic phase transition at T2 = 4.4±0.1K and the quadrupolar transition at T1 ∼ 6.8K, we find orbital ordering at T0 = 7.6±0.1K concomitant with a symmetry change from hexagonal to orthorhombic. A striking feature is the splitting of the phase transition at T...

Fluoride ion channels of the Fluc family combat toxicity arising from accumulation of environmental F-. Although crystal structures are known, the densely packed pore region has precluded delineation of the ion pathway. Here we chart out the Fluc pore and characterize its chemical requirements for transport. A ladder of H-bond donating residues creates a 'polar track' demarking the ion-conducti...

the charge-transfer complexation reaction between iodine and dibenzo- 18-crown- 6 (db18c6) has been studied spectrophotometrically in chloroform solution at different temperatures. the resulting donor-acceptor complex was formulated as (db 18c6…i )i . the spectrophotometric results , as well as the conductivity measurements, indicated that the gradual release of tiiodide ion from its contact io...

Knowledge of ionicity is requisite for successful identification of those salt qualities required to design and couple the most appropriate fluid for performance of an intended chemical function. We report on utilisation of (35)Cl(-) quadrupolar coupling constants (C(Q)) to quantitatively assess the ionicities of given chloride salts, by exploiting the electronic response of the quadrupolar chl...