Two-dimensional tunneling of hydrogen in a Norrish type II process of a ketone

The two-dimensional tunneling of hydrogen in a Norrish type II process of pentane-2-one is examined through a potential barrier obtained by means of ab initio molecular orbital methods with a 6-31G∗∗ basis set and with a correction for electron correlation. The tunneling probability has been estimated using the WKB method with a polynomial function of the energy potential. Two-dimensional calculations lead to a lowering of the tunneling probability obtained by the conventional one-dimensional calculations provided the barrier oscillations are treated as anharmonic.