19259-90-6Relevant articles and documents
Santucci et al.
, p. 1262 (1969)
Photolysis of matrix-isolated acetyl chloride and infrared spectrum of the 1:1 molecular complex of hydrogen chloride with ketene in solid argon
Kogure, N.,Ono, T.,Suzuki, E.,Watari, F.
, p. 1 - 4 (1993)
Acetyl chloride in an argon matrix decomposed on irradiation to generate ketene and hydrogen chloride, which formed the ketene...HCl complex.The fundamental vibrational frequency of HCl in the complex was observed at 2679 cm-1, i.e. 191 cm-1 below the frequency of the corresponding HCl monomer in solid argon.The fundamental frequency of DCl in the ketene-d2...DCl complex formed by photolysis of acetyl chloride-d3 was observed at 1939 cm-1, i.e. 140 cm-1 below the frequency of the corresponding DCl monomer in solid argon.
"Meta elimination," a diagnostic fragmentation in mass spectrometry
Attygalle, Athula B.,Nishshanka, Upul,Weisbecker, Carl S.
experimental part, p. 1515 - 1525 (2012/05/05)
The diagnostic value of the "ortho effect" for unknown identification by mass spectrometry is well known. Here, we report the existence of a novel "meta effect," which adds to the repertoire of useful mass spectrometric fragmentation mechanisms. For example, the meta-specific elimination pathway described in this report enables unequivocal identification of meta isomers from ortho and para isomers of carboxyanilides. The reaction follows a specific path to eliminate a molecule of meta-benzyne, from the anion produced after the initial decarboxylation of the precursor. Consequently, in the CID spectra of carboxyanilides, a peak for the (R-CO-NH)- anion is observed only for the meta isomers. For example, the peaks observed at m/z 58, 86, 120, 128, and 170 from acetamido-, butamido-, benzamido, heptamido-, and decanamido-benzoates, respectively, were specific only to the spectra of meta isomers.
New transition-state models and kinetics of elimination reactions of tertiary alcohols over aluminum oxide
Dabbagh,Salehi, J. Mohammad
, p. 7619 - 7627 (2007/10/03)
A new transition-state model was developed in order to justify the anti intramolecular E2 elimination with cis (Z)-preference over pure alumina and interinolecular E2 elimination with trans (E)-preference over doped alumina. The reactions of model compounds 1,2,3-triphenyl-2-propanol (1), 1,2-diphenyl-2-propanol (2), and 3,3,3-trideuterio-1,2-diphenyl-2-propanol (3) with aluminum oxides with a pH range of 4.5-9.5 and thorium oxide in the temperature range of 200-350 °C in 2-hexanol have been investigated. Over acidic alumina (pH = 4.5 ±0.5), the ratio of E-isomer to Z-isomer (E/Z ? 2) for 2 was found to remain unchanged in this temperature range. At 300 °C, however, Saytzeff elimination favored Hofmann. Over pure alumina the E/Z ratio was equal to 0.650 (2-alkene/1-alkene = 0.750). At equilibrium, the E/Z ratio for 2 was equal to 4.5 with the formation of trace amounts of Hofmann adducts. The ratio of Saytzeff to Hofmann elimination was found to be pH independent. Any decrease in pH caused a slight increase in the E/Z ratio. The average primary kinetic isotope effect (kH/kD) for elimination at 230 °C was equal to 3.775 ± 0.227. The ratio of E/Z over thorium oxide at 300 and 350 °C was similar to that of aluminum oxide at 300 °C, but the Saytzeff elimination was surprisingly favored over Hofmann! The energy of activation (Ea), entropy of activation (AS?), selectivity, isotope effect (kH/kD), and semiempirical calculation (AM1) all agreed with concerted E2 elimination.
