Quantum chemical study on the mechanism for the cycloreversion of anthracene-benzene and naphthalene-benzene [4Â +Â 4] cycloadducts

► The potential energy curves for the cycloreversion of anthracene-benzene and naphthalene-benzene cycloadducts are studied. ► The reaction proceeds adiabatically from the σ, σ∗ excited state yielding the 1La state of anthracene or naphthalene. ► The fluorescent 1Lb state of naphthalene is formed via the internal conversion from the 1La state.