title: Systematic Modulation of the Fluorescence Brightness in Boron-Dipyrromethene (BODIPY)-Tagged N-Heterocyclic Carbene (NHC)-Gold-Thiolates.
abstract: Five different highly fluorescent boron-dipyrromethene (BODIPY)-tagged N-heterocyclic carbene NHC-gold halide complexes were synthesized. The substitution of the halogeno ligand by 4-substituted aryl thiolates leads to a decrease in the brightness of the complexes. This decrease depends on the electronic nature of the thiols, being most pronounced with highly electron-rich thiols (4-R=NMe2). The brightness of the gold thiolates also depends on the distance between the sulfur atom and the BODIPY moiety. The systematic variation of the electron density of [(NHC-bodipy)Au(SC6H4R)] (via different R groups) enables the systematic variation of the fluorescence brightness of an appended BODIPY fluorophore. Based on this and supported by DFT calculations, a photoinduced electron-transfer quenching appears to be the dominant mechanism controlling the brightness of the appended BODIPY dye.
authors.affiliation: Organometallic Chemistry, TU Darmstadt, Alarich-Weiss-Str. 12, 64287, Darmstadt, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Halter
authors.affiliation: Organometallic Chemistry, TU Darmstadt, Alarich-Weiss-Str. 12, 64287, Darmstadt, Germany.
authors.forename: Roman
authors.initials: R
authors.lastname: Vasiuta
authors.affiliation: Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain.
authors.forename: Israel
authors.identifier: http://orcid.org/0000-0002-0186-9774
authors.initials: I
authors.lastname: Fernández
authors.affiliation: Organometallic Chemistry, TU Darmstadt, Alarich-Weiss-Str. 12, 64287, Darmstadt, Germany.
authors.forename: Herbert
authors.identifier: http://orcid.org/0000-0002-2257-983X
authors.initials: H
authors.lastname: Plenio
keywords: BODIPY; fluorescence; gold; ligand substitution; photoinduced electron transfer