Heteroatom Effect at C7 of Norbornadiene-Quadricyclane System for Maximizing the Solar Energy Storage: DFT Calculations

An attempt is made to maximize the solar energy storage in norbornadiene (1)/quadricyclane (2) system, through exchanging of heteroatoms at C7 of 1 and 2; calculating the corresponding energies at MP2/6-311++G(3df,2p)//B3LYP/6-311++G(3df,2p) and B3LYP/6-311++G** levels of theory. Free energy gaps between 1X and 2X, ΔG(1x)-(2x), and solar energy storage is the most for 1Se, 1As and 1Al from group VIII, VII and III of the Table, respectively