Computationally guided circularly polarized luminescence simulations in chiral adaptive supramolecular systems

Abstract

Chirality and chiral phenomena associated with electromagnetic waves universally arise across many different forms, which involve transitions between states with opposite symmetries. Recently, adaptive chirality (the post-induced chirality in initial achiral environments by asymmetric guests) has undergone a burgeoning development owing to the multitasking features of tetraphenylethene (TPE) faces restricted in particular chemical buildings. Conceptually, initial achiral hosts bearing TPE commutable helical units (P/M forms) can interface with enantiopure guests to produce supramolecular asymmetric luminophores (CPL-active molecules). In these terms, a robust interpretation of these chiroptical events is yet to be computationally provided. In this study, we provide a solid and accessible computational workflow able to accurately predict the circularly polarized luminescence spectra of TPE-based hosts with stereogenic chiral guests (deoxyribonucleotide monophosphate homo-dimers, dipeptide homo-pairs and organic acids). In virtue of a preliminary DFT benchmark, we decided to use the ωB97XD functional to realize a conformational investigation of H-bonded chiral multicomponents encapsulated within TPE-based architectures in the first excited state by means of Born–Oppenheimer molecular dynamics. Finally, an extensive TD-DFT examination concerning exchange–correlation functionals and basis sets revealed the B3LYP/6-311G(d,p) level as the most precise and transferable method to meticulously model the CPL sign, band shape and peak position in TPE-based chiral reconfigurable host–guest complexes.