Aggregation-Induced Polarization (AIP) of Racemic and Achiral Organic Molecules Leading to Asymmetric Elliptical Polarization Displaying Optical Rotation
Abstract
Aggregation-induced polarization (AIP) was found to enable racemic and achiral molecules to show optical rotation in clear and transparent solutions. It also leads to the specific rotation of chiral molecules to be affected by their concentrations instead of being nearly consistent as documented in literature and textbooks. In this work, we examined AIP effect in a series of solutions containing small racemic, achiral and chiral molecules. After being irradiated with UVvis in prolonged periods inside polarimeter, racemic compounds of rac-BINOL, rac-BINAP, rac-BINAP oxide and achiral aggregation-induced emission (AIE) luminogens and 4CzIPN showed transient optical rotations in cosolvents of THF and water, i.e., the optical rotation appeared during an induction period and later returned toward baseline. Specific rotations of chiral cinchona derivatives and R or S BINOL/BINAP retained their intrinsic sign but showed their concentration dependence. Dynamic light scattering (DLS) directly revealed concentration-dependent aggregates’ populations, while Photoluminescence (PL) also provided complementary evidence for aggregation-dependent behavior in the racemic and cinchona series. Changes in solution state organization can therefore appear as a transient net rotation in racemic or achiral samples, and as specific rotation changes of an existing chiral response. The asymmetric polarization induced by
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BibTeX
@misc{yuan2026aggregationinduced,
title = {{Aggregation-Induced Polarization (AIP) of Racemic and Achiral Organic Molecules Leading to Asymmetric Elliptical Polarization Displaying Optical Rotation}},
author = {Qingkai Yuan and Hao Liu and Zacheaus M. Akinpelu and Minhao Liu and Guigen Li},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010316/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010316/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Aggregation-Induced Polarization (AIP) of Racemic and Achiral Organic Molecules Leading to Asymmetric Elliptical Polarization Displaying Optical Rotation
AU - Qingkai Yuan
AU - Hao Liu
AU - Zacheaus M. Akinpelu
AU - Minhao Liu
AU - Guigen Li
PY - 2026
DA - 2026/10/12
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010316/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010316/v1
AB - Aggregation-induced polarization (AIP) was found to enable racemic and achiral molecules to show optical rotation in clear and transparent solutions. It also leads to the specific rotation of chiral molecules to be affected by their concentrations instead of being nearly consistent as documented in literature and textbooks. In this work, we examined AIP effect in a series of solutions containing small racemic, achiral and chiral molecules. After being irradiated with UVvis in prolonged periods inside polarimeter, racemic compounds of rac-BINOL, rac-BINAP, rac-BINAP oxide and achiral aggregation-induced emission (AIE) luminogens and 4CzIPN showed transient optical rotations in cosolvents of THF and water, i.e., the optical rotation appeared during an induction period and later returned toward baseline. Specific rotations of chiral cinchona derivatives and R or S BINOL/BINAP retained their intrinsic sign but showed their concentration dependence. Dynamic light scattering (DLS) directly revealed concentration-dependent aggregates’ populations, while Photoluminescence (PL) also provided complementary evidence for aggregation-dependent behavior in the racemic and cinchona series. Changes in solution state organization can therefore appear as a transient net rotation in racemic or achiral samples, and as specific rotation changes of an existing chiral response. The asymmetric polarization induced by
ER -