Thermal decomposition of transannular peroxide of anthracene (POA) (or 9,10-epidioxido anthracene) was studied by means of electron paramagnetic resonance spectroscopy (EPR) in the solid as well as in the liquid phase...Thermal decomposition of transannular peroxide of anthracene (POA) (or 9,10-epidioxido anthracene) was studied by means of electron paramagnetic resonance spectroscopy (EPR) in the solid as well as in the liquid phases. Decomposition process proceeds via cleavage of the O-O bridge of the POA molecule, generating thus an alcoxy intermediate radical. Its concentration increases to a certain equilibrium stage during the time scale of the experiment. EPR spectra in the solid state were of the singlet type at the temperatures over 350 K, a doublet like anisotropic spectra were measured at the room temperature, both having g-value 2.0033. EPR spectrum from POA decomposed in benzene indicates four protons with higher (2aH = 0.305 mT, 2aH = 0.335 mT) and four protons with a lower (2aH = 0.075 mT, 2aH = 0.105 mT) splitting constants, corresponding well the radical expected after cleavage of O-O bridge.展开更多
基金support of Operational Program Research and Development for Innovations co-funded by the European Regional Development Fund(ERDF)and national budget of Czech Republic within the framework of the Centre of Polymer Systems project(reg.number CZ.1.05/2.1.00/03.0111)supported by the Scientific Grant Agency of the Slovak Republic(Project VEGA/1/0018/09).
文摘Thermal decomposition of transannular peroxide of anthracene (POA) (or 9,10-epidioxido anthracene) was studied by means of electron paramagnetic resonance spectroscopy (EPR) in the solid as well as in the liquid phases. Decomposition process proceeds via cleavage of the O-O bridge of the POA molecule, generating thus an alcoxy intermediate radical. Its concentration increases to a certain equilibrium stage during the time scale of the experiment. EPR spectra in the solid state were of the singlet type at the temperatures over 350 K, a doublet like anisotropic spectra were measured at the room temperature, both having g-value 2.0033. EPR spectrum from POA decomposed in benzene indicates four protons with higher (2aH = 0.305 mT, 2aH = 0.335 mT) and four protons with a lower (2aH = 0.075 mT, 2aH = 0.105 mT) splitting constants, corresponding well the radical expected after cleavage of O-O bridge.
