LAUSR

Cucurbit[8]uril (CB[8])-stabilized charge transfer pair between 2, 6-dihydroxynaphthalene and methylviologen derivative has been theoretically studied at the PBE0-D3/6-311+G* level. The structure, interaction energy, electron density, and frontier orbital properties of the complex inside CB[8] have been computed and compared with the corresponding properties in gas and water at the same level. Geometric and energetic results show that the guest pair inside CB[8] represents closer packing and stronger binding energy. The VMD program makes the binding strength visible, and the results are consistent with the binding energy results in gas, water, and CB[8]. The results of charge transfer excitation analysis suggest that CB[8] weakens the effect of solvation on the charge transfer excitation to make the complex show a charge transfer character. The calculation results of HOMO and LUMO orbitals suggest that the cavity of the CB[8] is helpful for the intermolecular charge transfer when compared with the case in water and is not involved in this process. This investigation would be useful for our understanding on the function of CB[8] and helpful in designing the supramolecular systems.