Showing papers by "Bruce S. Ault published in 1998"
TL;DR: In this article, the matrix isolation technique has been employed to isolate several intermediates, in sequence, in the oxidation of CH3OH by CrCl2O2, leading to the production of HCl and ClCrO2OCH3.
Abstract: The matrix isolation technique has been employed to isolate several intermediates, in sequence, in the oxidation of CH3OH by CrCl2O2. Consistent with previous theoretical calculations, a hydrogen-bonded complex formed initially after twin jet deposition and was enhanced by matrix annealing to 33 K. This complex was photodestroyed by Hg arc irradiation with λ < 500 nm, and led to the production of HCl and ClCrO2OCH3. These species were also produced by room temperature reaction of the two precursors in a flow system followed by rapid matrix trapping. Heating the flow reaction zone above 150 °C led to destruction of ClCrO2OCH3, and production of CH2O and HCl. Above 250 °C bands due to CH2O were destroyed and bands due to CO and CO2 grew in. High-level density functional calculations (B3LYP/6-311G*) were carried out to identify potential intermediates in this system and to provide theoretical vibrational spectra for comparison to experiment.
38 citations
TL;DR: The matrix isolation technique with twin-jet deposition has been coupled with infrared spectroscopy for the isolation, identification, and characterization of the 1:1 complexes of TiF4 with NH3 and (CH3)3N as discussed by the authors.
Abstract: The matrix isolation technique with twin-jet deposition has been coupled with infrared spectroscopy for the isolation, identification, and characterization of the 1:1 complexes of TiF4 with NH3 and (CH3)3N. For each of these complexes, two perturbed Ti−F stretching modes were observed to be red-shifted 40−90 cm-1 from the triply degenerate parent TiF4 mode at 792 cm-1, indicating a reduction of symmetry in the complex to at least C3v. In addition, the symmetric deformation mode of the NH3 subunit shifted 228 cm-1 to higher energy, indicating that TiF4 is a moderate strength Lewis acid. Merged jet deposition of these reagents led to no observed product in the matrix and no parent TiF4, suggesting that a reaction to form a nonvolatile product in the merged or reaction region had occurred, probably forming the very stable 1:2 complex.
5 citations