posted on 2021-06-11, 09:43authored byYanqi Liu, Jianfeng Jia, Zeyu Liu, Ning Pu, Gang Ye, Wei Wang, Tongyang Hu, Tao Qi, Jing Chen
Coordination-driven
metal–phenolic assembly, a mechanism
associated with many essential biological functions, is being actively
exploited for engineering of advanced materials. However, a critical
challenge remains in the regulation of the dynamic metal–phenolic
networks to overcome the kinetic trapping for well-controlled nanofilm
formation. This study presents an adaptable competitive binding strategy
to shape the metal–phenolic complexes while modulating their
assembly behaviors. Kinetically stable metal–phenolic assemblies
with homogeneous hydrodynamic diameters are identified as a new class
of metal–phenolic building blocks. Spectroscopic studies and
density functional theory calculations reveal an inner-sphere complexation
of the competitive ligands to the metal centers of bis-complex metal–phenolic
species. Quantitative insights into the availability of competitive
ligands are achieved, and a series of applicable ligands are located.
Particularly, these kinetically stable building blocks, with good
dispersibility in both aqueous and organic media, revolutionize the
processing of metal–phenolic nanofilms, enabling the use of
versatile industrially friendly methods including homogeneous spray
coating, vertical deposition self-assembly, and ink-jet printing.
The obtained films exhibit superior properties in terms of mechanical
strength (EY = 13.7 GPa), surface smoothness,
and reinforced adhesion force. This study provides new mechanistic
understanding of the coordinative metal–phenolic assembly and
activates the toolkit of supramolecular chemistry for controllable
engineering of metal–organic hybrid films for multidisciplinary
applications.