Heterochiral Doped Supramolecular Coordination Networks for High-Performance Optoelectronics

Chiral self-sorting
has great potential for constructing new complex
structures and determining chirality-dependent properties in multicomponent
mixtures. However, it is still of great challenge to achieve high
fidelity chiral self-discrimination. Besides, the researches on the
coordination polymers or metal–organic frameworks for micro/nanooptoelectronics
are still rare due to their low conductivity and difficulty in developing
a rapid and simple scale-up synthetic method. Here, heterochiral supramolecular
coordination networks (SCNs) were synthesized by the solvothermal
reaction of naphthalene diimide enantiomers and cadmium iodide, using
the chirality as a synthetic tuning parameter to control the morphologies.
Intriguingly, heterochiral micro/nanocrystals exhibited photochromic
and photodetecting properties. Furthermore, we also developed a simple
and efficient doping method to enhance the conductivity and photoresponsivity
of micro/nanocrystals using hydrazine. From experimental and theoretical
studies, the mechanism was suggested as follows: the radicals in the
singly occupied molecular orbital level of the ligands provide charge
carriers that can undergo “through-space” transport
between π–π stacked ligands and the electron transfer
from adsorbed hydrazine to the SCNs results in reduction of energy
gap, leading to increased conductivity. Our findings demonstrate a
simple and powerful strategy for implementing coordination networks
with redox ligands for micro/nanooptoelectronic applications.