Potent relay stations for electron transfer in proteins: π∴π Three-electron bonds

The paper is of relevance to weak interactions between two parallel rings of close aromatic amino acids, which may participate in electron hole transport in proteins. The ab initio calculations reveal the possibility for the formation of the πâ̂́π three-electron bond between two parallel aromatic rings, facilitating electron hole transport in proteins as the effective relay stations. The relay functionality of these special structures comes from their lower local ionization energies and proper binding energies, which vary with the different aromatic amino acids and the arrangements of the same aromatic rings according to the local microsurroundings in proteins.