AUTHOR=Tabone Roberta , Feser Dominik , Lemma Enrico D. , Schepers Ute , Bizzarri Claudia TITLE=Intriguing Heteroleptic ZnII bis(dipyrrinato) Emitters in the Far-Red Region With Large Pseudo-Stokes Shift for Bioimaging JOURNAL=Frontiers in Chemistry VOLUME=9 YEAR=2021 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.754420 DOI=10.3389/fchem.2021.754420 ISSN=2296-2646 ABSTRACT=
Novel heteroleptic ZnII bis(dipyrrinato) complexes were prepared as intriguing emitters. With our tailor-made design, we achieved far-red emissive complexes with a photoluminescence quantum yield up to 45% in dimethylsulfoxide and 70% in toluene. This means that heteroleptic ZnII bis(dipyrrinato) complexes retain very intense emission also in polar solvents, in contrast to their homoleptic counterparts, which we prepared for comparing the photophysical properties. It is evident from the absorption and excitation spectra that heteroleptic complexes present the characteristic features of both ligands: the plain dipyrrin (Lp) and the π-extended dipyrrin (Lπ). On the contrary, the emission comes exclusively from the π-extended dipyrrin Lπ, suggesting an interligand nonradiative transition that causes a large