Theoretical study on the reaction of Be(3P) with methane

The reaction mechanism of Be(3P) with CH4 has been investigated theoretically at the QCISD(T)/6-311++G(d,p)//UB3LYP/6-311G(d) levels. It is shown that the excited Be atom can readily insert into C-H bond of methane without a barrier and the reaction proceeds through the insertion intermediate H-Be-CH3(3A′) followed by three processes, i.e., direct decomposition, rearrangement and intersystem crossing. Five possible reaction channels, yielding organoberyllium compounds BeH, BeCH3, HBeCH2, HBeCH and HBeCH3(1A1), respectively, have been examined. The high reactivity of Be(3P) atom with methane is supposed to be due to small steric hindrance compared with other group 2 and 12 metal atoms. Our results well rationalize the experimental observations.