Sensitised LnIIIEmission and Excited-State Dynamics of Cofacial 'Pacman' Porphyrin Terpyridine Complexes.
An asymmetric 'Pacman' metalloligand, [Zn(PXT)], which features a cofacial ZnII-porphyrin unit (P) covalently attached to a terpyridine (T) chelating group via a rigid xanthene (X) moiety has been prepared, and its interactions with several different trivalent LnIIIcations (NdIII, GdIII, YbIIIand LuIII) have been examined. The formation of 1:1 metal-ligand complexes was monitored by1H NMR spectroscopy and corroborated by HRMS data. Solution-stability constants were determined by UV/Vis titration, and the resulting complexes with NdIIIor YbIIIdemonstrated sensitised emission in the NIR region due to energy transfer from the ZnII-porphyrin donor to LnIIIacceptor. The energy transfer was investigated by transient absorption techniques, which provided insight into the kinetics and efficiency of the antenna effect.
School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, 4072, Australia.
Jane Y
JY
Liew
School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, 4072, Australia.
Joshua J
JJ
Brown
School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, 4072, Australia. egmoore@uq.edu.au.
Evan G
EG
Moore
Institute of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany. matthias.schwalbe@hu-berlin.de.
Matthias
M
Schwalbe
energy transfer; lanthanides; terpyridines; transient absorption; zinc porphyrins