- Preparation of 7-alkylcyclohepta-1,3,5-trienes from organometallics and either tropylium tetrafluoroborate or 7-ethoxycyclohepta-1,3,5-triene
-
The reaction of several organolithium compounds and the reaction of α-unsaturated organozinc and organoaluminium compounds with either the readily prepared tropylium tetrafluoroborate or with 7-ethoxycyclohepta-1,3,5-triene give the corresponding 7-alkylcyclohepta-1,3,5-trienes.On the other hand, with organomagnesium compounds, only 7-ethoxycyclohepta-1,3,5-triene gives the expected 7-alkylcyclohepta-1,3,5-trienes while the reaction of tropylium tetrafluoroborate is abnormal.
- Picotin, G.,Faye, A.,Miginiac, P.
-
p. 245 - 251
(2007/10/02)
-
- Energy Dependence of Collisional Deactivation of Highly Vibrationally Excited Ethylcycloheptatriene
-
Collisional self-deactivation of 7-ethylcycloheptatriene photoactivated to total internal energies of 123 kcal/mol (240 nm), 111 kcal/mol (265 nm), 106 kcal/mol (280 nm), and 100 kcal/mol (295 nm) has been investigated.The reaction products consisted of the positional isomers 1-, 2-, and 3-ethylcycloheptatriene and methyl-ethyl-substituted benzenes formed by structural isomerization.The pressure dependence of reaction products resulting from positional and structural isomerization was determined at each wavelength in a series of experiments without added bath gases.The yield of structural isomerization products decreased with increasing pressure, indicative of collisional stabilization of photoactivated ethylcycloheptatrienes.The ratio of positional to structural isomerization products increased with increasing pressure at fixed wavelength and increased with increasing wavelength at fixed pressure, consistent with a shorter lifetime for positional isomerization than for structural isomerization.Master equation calculations were done using RRKM theory and a stepladder model for deactivation.The model calculations predict that the average energy removed per deactivating collision, (ΔE), increases with increasing excess energy of photoactivated 7-ethylcycloheptatriene.
- Chung, Gui-Yung,Carr, Robert W.
-
p. 2831 - 2837
(2007/10/02)
-
- Absorption Spectra and Photochemical Rearrangements of Xylene and Methylcycloheptatriene Cations in Solid Argon
-
Matrix photoionization experiments have been performed for several p-dialkylbenzenes and alkylcycloheptatrienes.Broad absorptions at 23500 and 34700 cm-1 following UV matrix two-photon ionization of p-xylene are assigned to the parent cation, in agreement with photodissociation spectra of gaseous cation.A broad absorption at 20240 cm-1 following vacuum-UV matrix photoionization of 7-methylcycloheptatriene is assigned to the parent cation, in agreement with the difference between photoelectron bands.Mercury arc photolysis has been used to activate the extensive rearrangements of the p-xylene and 7-methylcycloheptatriene cations, which finally rearrange to a common conjugated triene cation identified as a substituted methylenecyclohexadiene cation.
- Kelsall, Benuel J.,Andrews, Lester,McGarvey, Glenn J.
-
p. 1788 - 1795
(2007/10/02)
-