17217-57-1Relevant articles and documents
Zinc oxide nanocrystal quenching of emission from electron-rich ruthenium-bipyridine complexes
Hue, Ryan J.,Vatassery, Rajan,Mann, Kent R.,Gladfelter, Wayne L.
, p. 4630 - 4639 (2015)
A series of heteroleptic bipyridine ruthenium complexes were prepared using known synthetic methods. Each compound incorporated one electron withdrawing 4,4′-dicarboxylic acid-2,2′-bipyridine and two bipyridines each of which had electron donating dialkylamine substituents in the 4 and 4′ positions. The electronic absorption spectra exhibited absorptions that moved to lower energy as the donor ability of the amine substituent increased. Density functional calculations established that the HOMO was delocalized over the metal and two pyridine groups located trans to the pyridines of the dicarboxylic acid bipyridine. The LUMO was delocalized over the dicarboxylic acid bipyridine. Cyclic voltammetry of the deprotonated compounds exhibit one quasi-reversible oxidation and three reductions. Coupled with the emission data, the excited state reduction potentials were estimated to range from -0.93 to -1.03 V vs. NHE. Monodispersed 3.2 nm diameter nanocrystals (NCs) of zinc oxide were found to quench partially the excited state of the dyes via a static quenching electron transfer process involving the formation of a dyad of the complex and the NC. The magnitude of the partial quenching of complexed dyes was correlated to the distribution of band gaps for the NCs, which is an inverse function of diameter. Dyes attached to the NCs on the small end of the particle size distribution had electron transfer rates that were uncompetitive with radiative and nonradiative decay mechanisms. This journal is
Structural and Synthetic Insights into Pyridine Homocouplings Mediated by a β-Diketiminato Magnesium Amide Complex
Davin, Laia,Clegg, William,Kennedy, Alan R.,Probert, Michael R.,McLellan, Ross,Hevia, Eva
supporting information, p. 14830 - 14835 (2018/09/25)
The reaction of [(DippNacnac)Mg(TMP)] (1) with 4-subtituted pyridines proceeds via sequential regioselective metallation and 1,2-addition to furnish a range of symmetric 4,4′-R2-2,2′-bipyridines in good yield, representing a new entry into bipyridine synthesis. Interestingly, the reaction of 1 with 2-OMe-pyridine led to formation of asymmetric bipyridine 6, resulting from the C6-magnesiation of the heterocycle followed by a C?C coupling step by addition to the C2 position of a second, non-metallated molecule, and subsequent elimination of [DippNacnacMgOMe]2 (7). Synthesis combined with spectroscopic and structural analysis help rationalise the underlying processes resulting in the observed reactivity, and elucidate the key role that the sterically encumbered β-diketiminate ligand plays in determining regioselectivity.
Photoinduced solid-state coloring behavior of boronium complexes
Yoshino, Junro,Sekikawa, Tenku,Hatta, Naoya,Hayashi, Naoto,Higuchi, Hiroyuki
supporting information, p. 5489 - 5492 (2016/11/19)
Boronium complexes bearing a 9-borabicyclononane framework with a bipyridine-type ligand display photoinduced solid-state coloring behavior. While the identity of the substituents on the boron atom is critical to gain photoresponsive capability, modifying the nitrogen-containing ligand structure and its substituents provides a wide variation in the photoinduced solid color.
