Synthesis of [FeFe] Hydrogenase Mimics with Lipoic acid and its Selenium Analogue as Anchor Groups

Abstract

FeFe] hydrogenase (H 2 ase) mimicking complexes containing lipoic and selenolipoic acid moieties connected to 2-hydroxy-1,3-dithiopropane and 2-hydroxy-1,3-diselenopropane bridging ligands were synthesized and characterized using different spectroscopic methods. X-ray diffraction analysis was utilized to determine the molecular structure of a triphenylphosphane substituted analogue. Cyclic voltammetry (CV) investigations on the redox chemistry in presence and absence of acetic acid (AcOH) revealed differing behaviours among the mimics. IR spectroelectrochemistry (IR SEC) enabled deeper insights of structural changes during electrochemical measurements. The elaboration of surface confined systems was studied in preliminary experiments. CV experiments showed that the lipoic acid derivatives of the [FeFe] H 2 ase mimics formed wellorganized self-assembled monolayers (SAMs) on Pt electrodes, a promising result for future work.