TY - JOUR A1 - Moll, J. A1 - Wang, Cui A1 - Päpcke, A. A1 - Förster, C. A1 - Resch-Genger, Ute A1 - Lochbrunner, S. A1 - Heinze, K. T1 - Green Light Activation of Push-Pull Ruthenium(II) Complexes JF - Chemistry - A European Journal N2 - Synthesis, characterization, electrochemistry, and photophysics of novel homo- and heteroleptic ruthenium(II) complexes [Ru(cpmp)2] 2+ (22+) and [Ru(cpmp)(ddpd)]2+ (32+) bearing the tridentate ligands 6,2’’-carboxypyridyl-2,2’-methylamine-pyridylpyridine (cpmp) and N,N’-dimethyl-N,N’-dipyridin-2-ylpyridine-2,6-diamine (ddpd) are reported. The complexes possess one (32+) or two (22+) electron-deficient dipyridyl ketone fragments as electron accepting sites enabling intraligand charge transfer (ILCT), ligand-toligand charge transfer (LL’CT) and low-energy metal-to-ligand charge transfer (MLCT) absorptions. The latter peak around 544 nm (green light). 22+ shows 3MLCT phosphorescence in the red to near-infrared spectral region at room temperature in deaerated acetonitrile solution with an emission quantum yield of 1.3 % and a 3MLCT lifetime of 477 ns, while 3 2+ is much less luminescent. This different behaviour is ascribed to the energy gap law and the shape of the parasitic excited 3MC state potential energy surface. This study highlights the importance of the excited state energies and geometries for the actual excited state dynamics. Aromatic and aliphatic amines reductively quench the excited state of 22+ paving the way to photocatalytic applications using low-energy green light as exemplified with the green-light sensitized thiol-ene click reaction. KW - Green light excitation KW - Ruthenium(II) complexes KW - Phosphorescence KW - MLCT KW - Photoinduced electron transfer PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506759 DO - https://doi.org/10.1002/chem.202000871 SP - 1 EP - 13 PB - Wiley-VCH Verlag AN - OPUS4-50675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Otto, S. A1 - Moll, J. A1 - Förster, C. A1 - Geißler, Daniel A1 - Wang, Cui A1 - Resch-Genger, Ute A1 - Heinze, K. T1 - Three-in-One Crystal: The Coordination Diversity of Zinc Polypyridine Complexes JF - European Journal of Inorganic Chemistry N2 - The syntheses, structures, and photophysical properties of two new zinc(II) complexes bearing the tridentate N,N′-dimethyl-N,N′-dipyridin-2-ylpyridine-2,6-diamine (ddpd) ligand are presented. Structural investigations through single-crystal X-ray diffractometry, NMR spectroscopy, and density functional theory calculations revealed a diverse coordination behavior that depends on the counterion. Spectroscopic (UV/Vis and emission spectroscopy) and theoretical techniques (DFT and time-dependent DFT calculations) were employed to explore the photophysical properties of the complexes. KW - Zinc(II) complexes KW - X-ray diffractometry (XRD) KW - NMR spectroscopy KW - Density functional theory (DFT) KW - UV/Vis and emission spectroscopy PY - 2017 DO - https://doi.org/10.1002/ejic.201700948 SN - 1434-1948 SN - 1099-0682 VL - 43 SP - 5033 EP - 5040 PB - WILEY-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-43274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -