Observation of current rectification by the new bimetallic iron(<scp>iii</scp>) hydrophobe [FeIII2(LN4O6)] on Au|LB-molecule|Au devices

Targeting the development of stimulus-responsive molecular materials with electronic functionality, we have synthesized and studied the redox and electronic properties of a new bimetallic iron hydrophobe [FeIII2(LN4O6)] (1). The new H6LN4O6 ligand displays bicompartmental topology capable of accomodating two five-coordinate HSFeIII ions bridged by tetraaminobenzene at a close distance of ca. 8 A. We show that the metal-based reduction processes in (1) proceed sequentially, as observed for electronically coupled metal centers. This species forms a well-defined Pockels-Langmuir film at the air–water interface, with collapse pressure of 32 mN m−1. Langmuir–Blodgett monolayers were deposited on gold substrates and used to investigate current–voltage (I–V) measurements. This unprecedented bimetallic hydrophobe [FeIII2(LN4O6)] (1) shows unquestionable molecular rectification and displays a rectification ratio RR between 2 and 15.