Abstract: The reaction mechanisms of Ti, Na with O2 were investigated at the MP2/6-311+G(d) level. Ti and Na atom were assumed to approach O2 in the manner of horizontally or vertically with respect to the O—O bond, respectively. Both neutral Ti/Na+O2 and anionic (Ti/Na+O2)- systems were considered. The binding energy and the charge curves for each reaction pathway were analyzed in detail, to validate the optimal reaction mode. The reaction of metal atom (Ti and Na) with O2 is easier in negatively charged system (Ti/Na+O2)- than the neutral Ti/Na+O2, and the vertical pathway is more favorable than the horizontal. Meanwhile, the calculated results show that Ti atom prefers to react with the singlet O2 in both neutral and negatively charged systems. Na is easy to react with the singlet O2 in the neutral system, but with triplet O2 in negatively charged system. The potential energy surface of Ti with O2 reaction was also calculated at CCSD(T)/6-311++G(3df)//MP2/6-311+G(d) for Ti+O2 and (Ti+O2)- systems.

Key words: Ti, Na, O2, Reaction mechanism, Potential energy profile, First-principle calculation