Regulating the Morphology-Dependent Chiroptical Properties and Photoconductivity in Supramolecularly Orchestrated...

The work presents a systematic study to understand the morphology-dependent modulation of the chiroptical response and photoconductivity in helical assemblies in aqueous media. The outcome of the present investigation serves twin objectives by coupling the supramolecular strategies (tuning the noncovalent interaction pattern) with elegant designing of building blocks to achieve aforesaid targets. The T-shaped enantiomeric compound (-)-PZN-MET upon self-assembly yields double-helical architectures having strong chiroptical properties in the ground state (g_CD = -3.68 × 10^-2 at 292 nm) and high photoconductivity (ϕΣμ_max = 1.1 × 10^-4 cm² V^-1 s^-1). On the contrary, a V-shaped building block (-)-PZN-D-MET produces superhelical architectures having remarkable circularly polarized luminescence (g_lum = 10^-2) but relatively lower photoconductivity (ϕΣμ_max = 8.5 × 10^-5 cm² V^-1 s^-1). As indicated by collective experimental studies, from one perspective, the trade-off relationship between intra/intermolecular hydrogen bonding along with charge transfer characteristics has been employed to prepare bright CPL helical emitters in aqueous media. Conversely, the synergistic impact of intermolecular hydrogen bonding and π-π stacking has been unveiled to fabricate rigid double-helical assemblies having high photoconductivity.