Enantiopure Double ortho‐Oligophenylethynylene‐Based Helical Structures with Circularly Polarized Luminescence Activity. Issue 1 (12th September 2021)

• Record Type: Journal Article
• Authors: Reiné, Pablo; Ortuño, Ana M.; Resa, Sandra; Álvarez de Cienfuegos, Luis; Ribagorda, María; Mota, Antonio J.; Abbate, Sergio; Longhi, Giovanna; Miguel, Delia; Cuerva, Juan M.
• Is Part Of: ChemPhotoChem. Volume 6:Issue 1(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-09-12
• Subjects: chiroptical properties -- circularly polarized luminescence -- foldamers -- helical structures -- supramolecular metallofoldamers; Photochemistry -- Periodicals; Periodicals; Electronic journals; 541.35
• DOI: 10.1002/cptc.202100160
• Languages: English
• ISSNs: 2367-0932

Abstract

Abstract: In this paper, we describe the optical and chiroptical properties of an enantiopure multipodal ortho‐ oligophenylethynylene ( S, S, S, S) ‐1 presenting four chiral sulfoxide groups at the extremes. The presence of these groups together with alkynes allows the coordination with carbophilic Ag(I), and/or oxophilic Zn(II) cations, yielding double helical structures in an enantiopure way. In this sense, different behaviors in absorption, fluorescence, ECD and CPL spectra have been found depending on the stoichiometry and nature of the metal. We have observed that Zn(II) coordination favors an intensity increase of the electronic circular dichroism (ECD) spectra of compound ( S, S, S, S) ‐1 yielding an M ‐helicity in the ortho ‐oligophenylene ethynylene ( o ‐OPE) backbone. On the other hand, ECD spectra of final Ag(I) complex shows two different bands with an opposite sign to the free ligand, thus giving the P ‐helical isomer. In addition, circularly polarized luminescence (CPL) exhibit an enhanced intensity and negative sign in both complexes. Computational studies were also carried out, supporting the experimental results. Abstract : That's a wrap : The optical and chiroptical properties of an enantiopure multipodal ortho‐ oligophenylethynylene presenting four chiral sulfoxide groups at the extremes are presented. The presence of the sulfoxide groups together with alkynes allows coordination with carbophilic Ag(I), and/or oxophilic Zn(II) cations, yielding double helical structures in an enantiopure way.