Stereoselective Plasmonic Interaction in Peptide-tethered Photopolymerizable Diacetylenes Doped with Chiral Gold Nanoparticles

Angew Chem Int Ed Engl. 2023 Sep 11;62(37):e202306751. doi: 10.1002/anie.202306751. Epub 2023 Aug 3.

Abstract

Designing polymeric systems with ultra-high optical activity is instrumental in the pursuit of smart artificial chiroptical materials, including the fundamental understanding of structure/property relations. Herein, we report a diacetylene (DA) moiety flanked by chiral D- and L-FF dipeptide methyl esters that exhibits efficient topochemical photopolymerization in the solid phase to furnish polydiacetylene (PDA) with desired control over the chiroptical properties. The doping of the achiral gold nanoparticles provides plasmonic interaction with the PDAs to render asymmetric shape to the circular dichroism bands. With the judicious design of the chiral amino acid ligand appended to the AuNPs, we demonstrate the first example of selective chiral amplification mediated by stereo-structural matching of the polymer-plasmonic AuNP hybrid pairs. Such ordered self-assembly aided by topochemical polymerization in peptide-tethered PDA provides a smart strategy to produce soft responsive materials for applications in chiral photonics.

Keywords: This work was supported by the Air Force Office of Scientific Research (Program Officer: Dr. Kenneth Caster), Grant # FA9550-20-1-0267. We thank the Institute of Nano Science and Technology (INST), Mohali for providing infrastructure and characterization facilities. A. Pal acknowledges DST, SERB grant CRG/2020/004251 for the financial support..