Introducing Prism[4]arene: A Macrocycle with Enantiomerically Resolvable Inherent Chirality and Intriguing Chiroptical Properties

Year: 2025

Authors: Della Sala P., Talotta C., De Rosa M., Superchi S., Santoro E., Geremia S., Hickey N., Fuse M., Abbate S., Mazzeo G., Longhi G., Gaeta C.

Autors Affiliation: Univ Salerno, Dipartimento Chim & Biol A Zambelli, Lab Supramol Chem, I-84084 Fisciano, Salerno, Italy; Univ Basilicata, Dipartimento Sci Base & Applicate, I-85100 Potenza, Italy; Univ Trieste, Ctr Eccellenza Biocristallog, Dipartimento Sci Chim & Farmaceut, I-34127 Trieste, Italy; Univ Brescia, Dipartimento Med Mol & Traslaz, I-25123 Brescia, Italy; CNR, Ist Nazl Ott INO, Res Unit Brescia, I-25123 Brescia, Italy.

Abstract: This study presents the first report of an inherently chiral prismarene with resolved enantiomers. Prism[4]arenes, synthesized via a thermodynamic template approach using a tailor-made selective cation, effectively maintain their chirality due to their strained macrorings and narrow annuli, which prevent the flipping of naphthalene rings. The solid-state structure of the synthesized PrS[4] iPe revealed a racemic crystal composed of all-pR and all-pS enantiomeric pairs, forming supramolecular polymeric chains of homochiral molecules interlinked by intermolecular host-guest interactions. Both enantiomers were resolved by using chiral high-performance liquid chromatography (HPLC), and their chiroptical properties were thoroughly investigated. Configurational assignment was achieved through time-dependent density functional theory (TDDFT) computations alongside electronic circular dichroism/ultraviolet-visible (ECD/UV-vis) spectral analysis. Notably, the circularly polarized luminescence (CPL) properties exhibited a significant dissymmetry ratio of 0.008 for these prism[4]arenes, due to electric and magnetic dipole transition moments both directed along the cylinder axis. Furthermore, the ability of PrS[4] iPe to achieve enantioselective recognition with chiral ammonium guests was demonstrated.

Journal/Review: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

Volume: 147 (24)      Pages from: 20843  to: 20854

More Information: Financial support was from PRIN_PNRR 2022: Prismarene-based chemosensors for monitoring organic water contam inants (PRISMASENS) (PRIN_PNRR P2022XHLTX), CUP D53D23017250001. We acknowledge the CINECA award under the ISCRA initiative for the availability of high-performance computing resources and support.
KeyWords: Circularly-polarized Luminescence; Gas-phase; Noncovalent Complexes; Alpha-cyclodextrin; Recognition; Binding; Pseudorotaxanes; Dissociation; Hosts; Acids
DOI: 10.1021/jacs.5c04512