One-dimensional (1D) organic chiral
supramolecules have received
a great deal of attention for their promising applications in chiral
recognition systems, chemical sensors, catalysts, and optoelectronics.
Compared to modifications at the imide position of a perylene diimide
(PDI), few studies have explored bay substitution of chiral PDIs and
their self-assemblies into 1D nanomaterials. Herein, we describe the
synthesis of three bay-substituted PDIs and explore the effects of
bay substitution on supramolecular chirality by examining circular
dichroism spectra and the optoelectronic performance of chiral PDI
nanomaterials in phototransistors. Among the three fabricated self-assemblies,
nanomaterials based on (R)-CN-CPDI-Ph exhibited the
highest electron mobility of 0.17 cm2 V–1 s–1, a low threshold voltage of −1 V, and
enhanced optoelectronic performance. For example, the photoresponsivity
and external quantum efficiency of (R)-CN-CPDI-Ph
assemblies were 4-fold higher than those of (R)-2Br-CPDI-Ph
and (R)-2F-CPDI-Ph. All three nanomaterials exhibited
fast switching speeds compared with previously reported N-substituted
PDIs, suggesting that bay substitution can be an effective means of
achieving rapid photoswitching. A comprehensive study using density
functional theory calculations and crystal analyses revealed that
the enhanced optoelectronic performance of (R)-CN-CPDI-Ph
nanomaterials is related to the substitution of CN at the bay position
of PDI. This minor change provides simultaneous improvements in electron
injectability and structural order. Our findings demonstrate that
bay substitution can significantly impact the self-assembly, supramolecular
chirality, and optoelectronic properties of PDI nanomaterials.