title: On the Origin of the Chiro-Optical Activity in Supramolecular Assemblies: A Quantum Chemical Study of C3 Octopolar Systems.
abstract: First-principles quantum chemical approach has been used to understand the origin of the chiro-optical signal induced by the chiral aggregation of an achiral chromophore. The study was focused in predicting the circular dichroism (CD) spectra of different π-stacked columnar oligomers built with C3 star-shape molecular bricks. We studied the influence of the relevant structural self-assembly parameters on the CD spectra (i.e., the number of units, the rotation angle and the intermonomer distance). A detailed analysis was based on the MO topologies and the magnetic and electric transition dipole moments, the vectors which determine the CD intensities, has been conducted. We have rationalized the influence of the various structural factors of supramolecular self-assemblies in connection with the nature of their CD spectroscopic signal, which provides new avenues for structure-spectroscopic relationships.
authors.affiliation: Departamento de Química Física, Universidad de Málaga , 29071-Málaga, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Nieto-Ortega
authors.affiliation: Departamento de Química Física, Universidad de Málaga , 29071-Málaga, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Casado
authors.affiliation: Departamento de Química Física, Universidad de Málaga , 29071-Málaga, Spain.
authors.forename: Juan T
authors.initials: JT
authors.lastname: López Navarrete
authors.affiliation: Departamento de Química Orgánica, Universidad Autónoma de Madrid , Cantoblanco, 28049-Madrid, Spain.
authors.forename: Gunter
authors.initials: G
authors.lastname: Hennrich
authors.affiliation: Departamento de Química Física, Universidad de Málaga , 29071-Málaga, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Ramírez