Cheng Research Group

Functional Nanocomposite Materials


For the past few years we have been developing structurally simple hydrazone-based rotary switches and studying their pH and Lewis acid activation. As part of this effort, we have studied i) their isomerization mechanism, ii) induced them to undergo conformational and configurational changes, iii) conducted structure-property analysis, iv) developed a new zinc(II)-initiated activation mechanism (coordination-coupled deprotonation) and v) then used it in modulating two different molecular switches through proton relay cascades. These studies taught us how to manipulate intricate motion in these hydrazone-based systems. We are now applying this knowledge to control the properties of bulk materials, such as polymers and liquid crystals, push systems away from equilibrium, and bring about signal transduction and amplification cascades.

An offshoot of this project has been the development of a BF2-azo compound that can be switched between its trans and cis configurations using only visible light. We are currently looking into ways to red-shift the activation wavelength of this system so we can use it in various bio-applications.