Skip navigation

Please use this identifier to cite or link to this item: http://hdl.handle.net/20.500.12128/20528
Title: Ground- and excited-state properties of Re(I) carbonyl complexes - effect of triimine ligand core and appended heteroaromatic groups
Authors: Choroba, Katarzyna
Kotowicz, Sonia
Maroń, Anna
Świtlicka, Anna
Szłapa-Kula, Agata
Siwy, Mariola
Grzelak, Justyna
Sulowska, Karolina
Maćkowski, Sebastian
Schab-Balcerzak, Ewa
Machura, Barbara
Keywords: Re(I) carbonyl complexes; Triimine ligands; Photoluminescence; Electroluminescence; Femtosecond transient absorption spectroscopy
Issue Date: 2021
Citation: Dyes and Pigments, Vol. 192, (2021) art. no. 109472
Abstract: In this work, a series of six rhenium(I) complexes bearing 2,2′ :6′ ,2′′ -terpyridine (terpy), 2,6-di(thiazol-2-yl)pyridine (dtpy), and 2,6-di(pyrazin-2-yl)pyridine (dppy) with appended quinolin-2-yl and N-ethylcarbazol-3-yl groups were prepared and spectroscopically investigated to evaluate the photophysical consequences of both the trisheterocyclic core (terpy, dtpy and dppy) and the heterocyclic substituent. The [ReCl(CO)3(Ln-κ2N)] complexes are regarded as ideal candidates for getting structure–property relationships, while terpy-like framework represents an excellent structural backbone for structural modifications. The replacement of the peripheral pyridine rings of 2,2′ :6′ ,2′′ -terpyridine by thiazoles and pyrazines resulted in a significant red-shift of the absorption and emission of [ReCl(CO)3(Ln-κ2N)] due to stabilization of the ligand-centred LUMO orbital. Both quinoline and Nethylcarbazole are extended π-conjugation organic chromophores, but they differ in electron-donating abilities. The low-energy absorption band of Re(I) complexes with the triimine ligands bearing quinolin-2-yl group was contributed by the metal-to-ligand charge-transfer (MLCT) electronic transitions. The introduction of electrondonating N-ethylcarbazol-3-yl substituent into the triimine acceptor core resulted in the change of the character of the HOMO of Re(I) complexes and a significant increase of molar absorption coefficients of the longwavelength absorption, which was assigned to a combination of 1MLCT and 1ILCT (intraligand chargetransfer) transitions. Regardless of the appended heteroaromatic group, the emitting excited state of Re(I) terpy-based complexes was demonstrated to have predominant 3MLCT character, as evidenced by comprehensive studies including static and time-resolved emission spectroscopy along with ultrafast transient absorption measurements. The diodes with Re(I) complexes dispersed molecularly in a PVK:PBD matrix were emissive andeffects of the complex structure on colour of emitted light and its intensity was pronounced.
URI: http://hdl.handle.net/20.500.12128/20528
DOI: 10.1016/j.dyepig.2021.109472
ISSN: 0143-7208
1873-3743
Appears in Collections:Artykuły (WNŚiT)

Files in This Item:
File Description SizeFormat 
Choroba_Ground_and_excited_state.pdf10,63 MBAdobe PDFView/Open
Show full item record


Uznanie Autorstwa 3.0 Polska Creative Commons License Creative Commons