title: Quantifying through-space charge transfer dynamics in π-coupled molecular systems.
abstract: Understanding the role of intermolecular interaction on through-space charge transfer characteristics in π-stacked molecular systems is central to the rational design of electronic materials. However, a quantitative study of charge transfer in such systems is often difficult because of poor control over molecular morphology. Here we use the core-hole clock implementation of resonant photoemission spectroscopy to study the femtosecond charge-transfer dynamics in cyclophanes, which consist of two precisely stacked π-systems held together by aliphatic chains. We study two systems, [2,2]paracyclophane (22PCP) and [4,4]paracyclophane (44PCP), with inter-ring separations of 3.0 and 4.0 Å, respectively. We find that charge transfer across the π-coupled system of 44PCP is 20 times slower than in 22PCP. We attribute this difference to the decreased inter-ring electronic coupling in 44PCP. These measurements illustrate the use of core-hole clock spectroscopy as a general tool for quantifying through-space coupling in π-stacked systems.
authors.affiliation: Department of Applied Physics and Applied Mathematics, Columbia University, 500 W 120th Street, Room 201, New York 10027, New York, USA.
authors.forename: Arunabh
authors.initials: A
authors.lastname: Batra
authors.forename: Gregor
authors.initials: G
authors.lastname: Kladnik
authors.forename: Héctor
authors.initials: H
authors.lastname: Vázquez
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Meisner
authors.forename: Luca
authors.initials: L
authors.lastname: Floreano
authors.forename: Colin
authors.initials: C
authors.lastname: Nuckolls
authors.forename: Dean
authors.initials: D
authors.lastname: Cvetko
authors.forename: Alberto
authors.initials: A
authors.lastname: Morgante
authors.forename: Latha
authors.initials: L
authors.lastname: Venkataraman