Growth of Hybrid Chiral Thin Films by Molecular Layer Deposition Zinc/Cysteine as a Case Study

Atomic and molecular layer deposition (ALD and MLD) are techniques based on surface-directed self-limiting reactions that afford deposition of films controlled at the monolayer level and with extreme conformality, even on ultra-high-aspect-ratio and porous substrates. These methodologies are typically used to deposit thin films with desirable physical properties and functionality. Here, the MLD process is harnessed to demonstrate the growth of molecularly thin chiral films that inherit a desirable chemical property directly from the source precursor: using this innovative technique, enantioselective nanosurfaces are managed to be grown. Specifically, the formation of a Zn/Cysteine nanostructure by MLD is demonstrated for both the l- and d- enantiomers. The reaction and growth mechanism of these chiral hybrid inorganic-organic nanosurfaces are studied via various experimental procedures; their enantioselectivity is also demonstrated. The findings contribute to the understanding of the structure and chiral nature of hybrid inorganic-organic nanosurfaces and open the path to the bottom-up synthesis of diverse chiral nanosurfaces. These chiral nanostructures may play a key role in many aspects of chiral chemistry and are valuable for both fundamental science and practical applications.