Matrix spectroscopy of Ag, Ta, W, and Mo trapped in Ar and Xe using a triode sputtering source

Abstract

Inelastic helium scattering studies of the vibrational spectroscopy and dynamics of ordered Ar, Kr, and Xe multilayers physisorbed on Ag(111) J. Chem. Phys. 88, 7893 (1988); 10.1063/1.454301Multiple trapping sites and symmetry splitting in cryogenic matrices: Infrared spectroscopy of HCN in Ar, Kr, and Xe Atomic species of tungsten, molybdenum, and tantalum were extracted from a triode sputtering source and subsequently trapped in xenon and argon matrices at \0 'K. It is shown that this approach is particularly convenient for matrix isolation spectroscopy of materials which are difficult to vaporize. Good correlation with the gas spectrum is obtained for the strong spectral features. There is evidence that some spectral features are greatly enhanced in the matrix spectra over those in the gas spectra. Using silver/xenon as a prototype system it is shown that a wide range of plasma conditions can be used without aggregation. However, certain plasma conditions are identified which lead to weak spectra of siiver dimers. Spectral shifts due to matrix effects are found to be W / Ar = 850 em -I, W /Xe = 700 cm-I for Vi < 37 000 cm-I and 0 cm-I above, Mo/Ar = 2650 cm-I, Mo/Xe = 1150 cm-I , Ta/Xe = 980 cm-I for Vi < 33 000 cm-I and -3230 cm-I above. In the spectrum of Ta/Xe a remarkable red shift of 3230 cm -I for energies above 33 000 em -I is observed. This is in sharp contrast to the Ta spectrum in argon, where a surprisingly consistent perturbation of approximately 1000 cm-I to the blue is observed.

Electrical properties of sodium copper sulfide (Na3Cu4S4), a mixed-valence one-dimensional metal

“…The electrical conductivity for pressed pellets of Na3Cu4S4 has been measured with the four-probe van der Pauw technique. 11 For samples which we believe to be free of CuS contamination, the room-temperature conductivity is consistently near 300 "1 cm"1. Thus, for five separate preparations which gave both the correct crystal morphology and copper analyses, the range of conductivity values was 290-350 "1 cm"1, with an average = 328 ± 35 "1 cm"1.…”

Infrared Spectra of CH3−CrH, CH3−WH, CH2WH2, and CH⋮WH3Formed by Activation of CH4with Cr and W Atoms

“…This could derive from the rearrangement of III or from the direct excitation of W atoms to react with CH 4 . The 240−380 nm irradiation covers the 5 D → 5 F resonance absorption of W on the basis of the matrix absorption spectrum and the gas-phase lines, , and this excitation can reasonably be expected to activate the W reaction with CH 4 . Finally, these bands are in the W−H stretching region, but none of them was produced in previous investigations with H 2 as the reagent …”

Infrared Spectra of the CH3−CrF, CH2WHF, and CH⋮WH2F Molecules: Reversible Photochemical Interconversion by α-Hydrogen Transfer

“…Similarly, CH 2 WHF and CH⋮WH 2 F are interconverted by visible and UV light (Scheme 1). The ultraviolet irradiation contains the resonance absorptions of Mo and W in solid argon, , and this excitation can promote the insertion reaction to form more CH 3 −MoF and CH 3 −WF, which can undergo further rearrangements. The infrared spectra indicate that these α-H transfer reactions are completely reversible.…”