Twist Ferrocene Wires from Self-Assembly of Chiral Rod-Coil Organometallics

Abstract

Inspired by research on organometallics, the incorporation of transition metals into organic derivatives through covalent attachment has become a mature field. Because of improvements in synthesis, the ferrocene-based moiety is now a well-known organometallic moiety. Tunable ferrocene residues provide an attractive method to expand the range of properties. By taking advantage of self-assembly, various self-assembled organometallic morphologies including spheres, cylinders, vesicles, and lamellae with nanoscale iron-rich microdomains can be used in applications such as switches, transistors, and sensors for integration into microelectronic technology. Also, ordered nanostructures transform into semiconducting materials after oxidation and yield iron-rich magnetic ceramics after pyrolysis treatment. Helical morphologies can be obtained from the self-assembly of chiral supramolecules such as chiral liquid crystals, folded oligomers, chiral counterions, chiral dendrimers, dendron rod–coils, chiral homopolymers, chiral block copolymers, and chiral discotic molecules. In our previous studies, the self-assembly of a series of chiral Schiff based rod–coil amphiphiles was systematically examined. The self-assembled helical superstructures could be induced by chiral sugar, and a morphological transformation from helical to platelet-like morphology was driven by simply increasing the hydrophobic chain length at the chain end of the chiral rod–coil amphiphiles. The helical morphology results from the steric-hindrance effect of the chiral sugar packing in the self-assembly. Herein we aim to create iron-rich spiral superstructures by taking advantage of the self-assembly of chiral Schiff based rod–coil molecules that are end-capped with ferrocene (namely, chiral rod–coil organometallics). Figure 1