Dynamic NMR study showed that 9.10-dimethyl-9-vinylphenanthrenium ion, generated under the conditions ensuring its "long life." undergoes very fast (Delta G(not equal) = 24.4 kJ/mol at -103 degrees C) degenerate 1,2-shift of the vinyl group. According to the DFT quantum-chemical calculations, the process is one-step, and the low energy of formation of the activated complex is determined by effective participation of 71 electrons of the vinyl group in delocalization of the positive charge; no such delocalization is intrinsic to the initial ion.
Dynamic NMR study showed that 9.10-dimethyl-9-vinylphenanthrenium ion, generated under the conditions ensuring its "long life." undergoes very fast (Delta G(not equal) = 24.4 kJ/mol at -103 degrees C) degenerate 1,2-shift of the vinyl group. According to the DFT quantum-chemical calculations, the process is one-step, and the low energy of formation of the activated complex is determined by effective participation of 71 electrons of the vinyl group in delocalization of the positive charge; no such delocalization is intrinsic to the initial ion.