title: Structure-property relationships in an iridium(III) bis(terpyridine) complex with extended conjugated side chains.
abstract: Iridium(III) bis(terpyridine) complexes are known as excellent triplet emitters with emission lifetimes in the order of microseconds. We report the homoleptic complex [IrL2](3+) (L = 4'-(4-2,5-bis(octyloxy)-4-styrylphenyl)ethinyl)phenyl)-2,2':6',2″-terpyridine) that shows no detectable phosphorescence at room temperature but shows fluorescence. Emission spectra of [IrL2](3+) depend on the excitation wavelength. The origin of this behavior is studied with the help of results from (TD-)DFT calculations and is attributed to the selective excitation of different rotamers and isomers. Femtosecond-transient absorption experiments give further support for this interpretation as the specific excited-state absorption features of Z- and E-stilbene motives can be identified.
authors.affiliation: Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena , Helmholtzweg 4, 07743 Jena, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Kübel
authors.forename: Andreas
authors.initials: A
authors.lastname: Winter
authors.forename: Ulrich S
authors.initials: US
authors.lastname: Schubert
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dietzek