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Why Are Dithienylethene‐Linked Biscobaltocenes so Hard to Photoswitch?
Author(s) -
Escribano Alejandra,
Steenbock Torben,
Stork Conrad,
Herrmann Carmen,
Heck Jürgen
Publication year - 2017
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201601146
Subject(s) - molecular switch , photoswitch , density functional theory , chemistry , thiophene , cobalt , ring (chemistry) , photochemistry , diarylethene , excited state , photochromism , computational chemistry , molecule , inorganic chemistry , organic chemistry , atomic physics , physics
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.