Unimolecular Electrical Rectification in Hexadecylquinolinium Tricyanoquinodimethanide

Abstract

Macroscopic and nanoscopic current−voltage measurements reveal asymmetries in the DC electrical conductivity through Langmuir−Blodgett multilayers and even monolayers of γ-(n-hexadecyl)quinolinum tricyanoquinodimethanide, C16H33Q-3CNQ (5). These asymmetries are due to a transition of the ground-state zwitterion to an excited-state conformer which is probably neutral. Unimolecular electrical rectification by monolayers of 5 is unequivocally confirmed.