4,6-Dimethyl-o-quinone Methide and 4,6-Dimethylbenzoxete
摘要:
4,6-Dimethyl-o-quinone methide (4) was produced by FVP of alcohol 3 or of the trimer 6 and matrix isolated in Ar at 7.6 K. Photolysis of 4 with long wavelength light (>345 nm) at this temperature afforded 4,6-dimethylbenzoxete (5), which was observable up to room temperature in the solid state in the absence of water. 5 can be converted back to 4 by UV irradiation at 254/190 nm. Quantum chemical calculations on the thermal interconversion of 4 and 5 indicate activation barriers of the order of 40 kcal/mol for 4 --> 5, and 30 kcal/mol for 5 --> 4. The dimer, trimer, and tetramer (8, 6, and 7) of 4 are characterized.
Raman spectroscopy to determine the average concentration in the liquid phase and concentration distribution in the gas phase surrounding desorbing linear arrays of binary microdroplets. For this study, monodisperse microdroplets consisting of acetylene dissolved in acetone were generated by a modified vibratingorificeaerosolgenerator (VOAG). The 2-dimensional concentration fields of acetylene desorbed