Showing papers by "Bruce S. Ault published in 1985"

Infrared matrix isolation study of the 1:1 molecular complexes of the hydrogen halides with methyl-substituted cyclopropanes

Abstract: The matrix isolation technique has been employed to isolate and characterize the hydrogen-bonded complexes formed between the hydrogen halides and a variety of methyl-substituted cyclopropanes. In each case, the complex was characterized by a shifting to lower energy of the hydrogen stretching frequency of the hydrogen halides; shifts slightly larger than those observed for the cyclopropane-hydrogen halide complexes were noted. In addition, a number of perturbed vibrational modes of the substituted cyclopropane were detected, and, as anticipated primary vibrations of the ring skeleton were affected. These perturbed modes, along with symmetry considerations, were used to deduce a likely structure for several of the complexes; for methylcyclopropane and 1,1-dimethylcyclopropane, hydrogen bonding to the carbon-carbon bond adjacent to the site of substitution was indicated. For several systems, a 1:2 complex was detected as well, but no definite structural information could be obtained. 38 references, 4 figures, 3 tables.

Infrared matrix isolation study of intermediate molecular complexes: complexes of tetrafluorogermane with oxygen-containing bases

Abstract: Etude et caracterisation des especes H 2 O•GeF 4 , CH 3 (H)O•GeF 4 , (CH 3 ) 2 O•GeF 4 , CD 2 O•GeF 4 et (CH 3 ) 2 CO•GeF 4 . Les spectres IR montrent que tous les composes sont lies par l'intermediaire de O au centre Ge. Comparaison avec des complexes deja etudies SiF 4

Matrix-isolation study of oxide-transfer reactions to halogen-containing Lewis acids: synthesis of the CO2F22- anion and attempted synthesis of the BF3O2- anion

Abstract: Synthese de l'anion CO 2 F 2 2− par reaction de Tl 2 O avec COF 2 (formation de Tl 2 + CO 2 F 2 2− ) qui elimine rapidement TlF en formant Tl + CO 2 F − . Un essai de preparation identique de BF 3 O 2− echoue

Matrix isolation study of the complexes of small-ring heterocycles. part 1. complexes of the hydrogen halides with ethylene oxide and related species

Abstract: The matrix isolation technique has been employed for the synthesis and isolation of the hydrogen-bonded complexes of oxygen-containing heterocycles with the hydrogen halides. For the saturated heterocycles, (CH 2 ) n O, n = 2–4, a 1:1 complex was observed in each case, while for furan, (CH) 4 O 1 both 1:1 and 1:2 complexes were observed. Infrared spectra of the 1:1 complexes of the saturated heterocycles with HF 1 HCl or HBr were dominated by intense, broad absorptions due to the hydrogen stretching motion of the complexed hydrogen halide, shifted considerably to lower energies. In addition, several vibrational modes of the perturbed base subunit in the complex were detected. The furan complexes, on the other hand, showed a much smaller shift of the hydrogen stretching motion, along with a considerably reduced bandwidth (4 cm −1 vs. approximately 50 cm −1 ). However, the spectra collectively suggested a stronger perturbation to the furan ring than to the skeletons of the saturated heterocycles, probably as a consequence of the rigidity of the furan ring. Within the sequence of saturated heterocycles, the degree of perturbation to the hydrogen halide, as measured by shift from the free hydrogen halide, increased with n , the number of CH 1 units in the ring. This is in accord with the proton affinities of these species, although the results for the furan complexes cannot be rationalized in this fashion.