Charge transfer through chemisorbed organic molecules – Neutralization of ionization processes at local sites in the molecule

The charge transfer through chemisorbed molecules has been studied by using normally oriented pyridine and benzoate molecules, chemisorbed on the Cu(1 1 0) surface. They yield H+ ions from the outer three C–H bond locations when ionized by electron impact. The local yield of these H+ ions allows the determination of the rate of electron transport through the molecule from the molecular contact point to the ionization position, causing ion neutralization. A superexchange (molecule-assisted tunneling) electron transfer process is found to control the electron-transfer event.