title: Why Are Dithienylethene-Linked Biscobaltocenes so Hard to Photoswitch?
abstract: Attaching an organometallic unit to a dithienylethene (DTE) molecular switch can allow one to vary its switching and spectroscopic properties, and to create switchable magnetic properties. In this work, two different dithienylethene molecular switches are used as a bridge between two cobalt sandwich units. The only difference between the switching cores is in the size of the cycloalkene ring connecting both thiophene rings. The complexes present different oxidation states for the cobalt atoms, which are demonstrated to determine the switching reaction. The UV/Vis measurements show that while the Co(I) complexes undergo the switching reaction, the Co(II,III) complexes switch poorly. Kohn-Sham density functional theory calculations indicate diabatic ring-closure mechanisms and a large number of excited states hindering the cyclization reaction and favoring the relaxation to the open form of the molecular switch.
authors.affiliation: Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King Platz 6, 20146, Hamburg, Germany.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Escribano
authors.affiliation: Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King Platz 6, 20146, Hamburg, Germany.
authors.forename: Torben
authors.initials: T
authors.lastname: Steenbock
authors.affiliation: Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King Platz 6, 20146, Hamburg, Germany.
authors.forename: Conrad
authors.initials: C
authors.lastname: Stork
authors.affiliation: Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King Platz 6, 20146, Hamburg, Germany.
authors.forename: Carmen
authors.initials: C
authors.lastname: Herrmann
authors.affiliation: Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King Platz 6, 20146, Hamburg, Germany.
authors.forename: Jürgen
authors.identifier: http://orcid.org/0000-0001-6468-6863
authors.initials: J
authors.lastname: Heck
keywords: cobaltocene; density functional calculations; dithienylethene; molecular switches; nuclear magnetic resonance