Chiroptical properties of supramolecular assemblies originate through the asymmetric coupling of molecular transition dipole moments. Herein, we report a joint experimental and theoretical investigation to understand the influence of intermolecular interactions on chiroptical properties, particularly during the early stages of self-assembly. In this regard, phenyleneethynylene-based molecular systems appended with d- and l-isomers of phenylalanine have been synthesized with one as well as two electronic transitions in the spectral region of interest. When self-assembled, these molecules show distinctly different chiroptical properties with the right- and left-handed organizations, guided by the chirality of phenylalanines. The standard exciton approach explains the observation of a bisignated electronic circular dichroism signal in systems with a single transition but fails when applied to systems with two nearby transitions. Here, we present a generalized exciton approach that addresses the unusual chiroptical properties of systems with multiple transitions.
Emergence of Chiroptical Properties in Molecular Assemblies of Phenyleneethynylenes: The Role of Quasi-degenerate Excitations / Kar, Sabnam; Swathi, Swathi; Sissa, Cristina; Painelli, Anna; Thomas, K. George. - In: THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS. - ISSN 1948-7185. - 9:16(2018), pp. 4584-4590. [10.1021/acs.jpclett.8b01988]
Emergence of Chiroptical Properties in Molecular Assemblies of Phenyleneethynylenes: The Role of Quasi-degenerate Excitations
Swathi, Swathi.;Sissa, Cristina
;Painelli, Anna;
2018-01-01
Abstract
Chiroptical properties of supramolecular assemblies originate through the asymmetric coupling of molecular transition dipole moments. Herein, we report a joint experimental and theoretical investigation to understand the influence of intermolecular interactions on chiroptical properties, particularly during the early stages of self-assembly. In this regard, phenyleneethynylene-based molecular systems appended with d- and l-isomers of phenylalanine have been synthesized with one as well as two electronic transitions in the spectral region of interest. When self-assembled, these molecules show distinctly different chiroptical properties with the right- and left-handed organizations, guided by the chirality of phenylalanines. The standard exciton approach explains the observation of a bisignated electronic circular dichroism signal in systems with a single transition but fails when applied to systems with two nearby transitions. Here, we present a generalized exciton approach that addresses the unusual chiroptical properties of systems with multiple transitions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.