​Chiral Perovskite Nanoplatelets
In this part of our group, we are developing new strategies to imprint chirality onto organic – inorganic lead halide perovskite nanomaterials. Figure 1 shows the structure of a perovskite nanoplatelet with the composition methylammonium (MA+, red) lead (green) halide (X-, blue) passivated with chiral ligands. The ligands are used to imprint chirality onto the perovskites and the halide composition controls the photophysical properties. Figure 2. shows absorbance spectra (left) and corresponding circular dichroism spectra (right) with pure and mixed halide compositions. We are interested in understanding the imprinting mechanism that is responsible for the observed chiro-optical properties, as well as improving upon the stability of the system and applying it to studies of the CISS effect.  

Figure 1. Diagram showing the crystal structure of a perovskite nanoplatelet.

Figure 2. Absorbance (left) and circular dichroism (right) spectra of chiral methylammonium lead halide perovskites with different halide compositions.

​Electropolymerization of Chiral Polymers
We are also looking at how magnetic fields can be used to tailor the secondary structure of electropolymerized thin films. More specifically, by controlling the spin exchange interaction between a ferromagnetic substrate and an electrooxidized achiral monomer we can impart a handedness to the resulting polymeric films. Figure 3. outlines this process. 

Figure 3. In the first step, electrooxidation of an achiral monomer in the presence of a magnetic field results in a preferred molecular orientation on the substrate. The ferromagnetic substrate – monomer interaction breaks the symmetry of the achiral molecule which allows for the formation of a chiral polymer upon electropolymerization.