Self-Assembled Polyhedral Oligosilsesquioxane Dendrimers for Circularly Polarized Luminescence Energy Transfer

Abstract

Polyhedral oligosilsesquioxanes (POSSs), as the smallest possible particle of silica, have rarely been incorporated into chiral nanostructures due to their shape-persistent structure and nanoscale size. In this work, we show the construction of two chiral organic building units containing POSS segments and the fabrication of chiral coassemblies as a matrix for circularly polarized luminescence (CPL) harvesting and color conversion. POSSs were separately conjugated to N-terminal aromatic glutamic dendrons appended with pyrene and naphthalimide luminophores, respectively, through an alkyl spacer (PGP and NGP). The structural similarity allows for the molecular intercalation between the species to afford chiral coassembled arrays, where energy transfer occurred due to the spectra overlap between the appended chromophores. Although PGP and NGP feature left-and right-CPL, their coassembly exhibited exclusive left-CPL identical to that of the energy transfer donor PGP. The energy transfer underwent a CPL light-harvesting modality to achieve specific chiroptical responses. This work illustrates an application of POSS moieties in controlling supramolecular chirality and CPL in functional nanoassemblies.

Discriminatory fluorescence and FRET in the chiral-perovskite/RhB system

“…11,12 However, due to the difficulty in introducing intrinsic chirality in NCs, 13 donor-acceptor systems involving chiral nanostructures remain unexplored. The related study could be expected to provide a deeper understanding on the intricate interplay of molecular chirality, 14 energy transfer, 15,16 and related chiroptical effects, 17 which holds the potential to exert a substantial influence on the advancement of optical devices, information storage techniques, and the frontier of quantum computing. Besides, in many previously published studies, energy transfer, discriminatory optical properties (CD and CPL) and chirality are generally considered concurrently.…”

Chiral molecular nanosilicas

“…POSS have been intensively incorporated into ordered architectures with versatile phases such as lamellar, bcc and a special A15 phase via delicate designs. [18][19][20] Due to the high crystallinity and apolar nature, POSS have seldom been applied to construct helical systems, and a precise control over the helical orientation of POSS has not been well accomplished to date. Foldamers are dened as synthetic polymers or oligomers adopting a compact conformation.…”

Manipulating Supramolecular Chirality and Circularly Polarized Luminescence of Cholesteryl Naphthalimides with Multiple Chiral Domains

“…Supramolecular self-assembly or coassembly, as a common way to construct biological macromolecules, has attracted extensive attention. The supramolecular assembly process is mainly dominated by intermolecular noncovalent weak forces, including π–π stacking, C–H···π, hydrogen-bonding interactions, halogen-bond interactions, metal–ligand coordination, van der Waals force, steric hindrance, CH/HC interactions, and so on. − Through rational design of building blocks and control of assembly environments, it is possible to control highly ordered arrangement of building blocks to form nanostructures with different dimensions, such as nanofibers (1D), , semipermeable membranes (2D), and vesicles (3D). , So far, a variety of building blocks have been developed, such as amino acid derivatives, , metal complexes, aromatic compounds, fullerenes, proteins, and polyhedral oligosilsesquioxanes (POSSs) − to construct multifunctional nanomaterials, which have been applied in drug delivery, catalysis, crystal engineering, synthesis of macromolecules, and other fields.…”