Ruthenium diimines are unique in their emissivity. Optical excitation with light of less than 500 nm leads to a strong emission in the 600-700 nm range. All emissive ruthenium complexes appear to undergo intersystem crossing from the absorptive singlet metal-to-ligand charge-transfer (MLCT) state to an emissive triplet MLCT state localized on the lowest-energy metal-ligand pair. In contrast to this currently accepted model, in which a single emissive state is populated and then equilibrates among other states based on a particular set of conditions, the excitation-wavelength dependence of the [(bpy)2RudppH]3+ emission suggests two emissive pathways. One populates an emissive MLCT state localized on a bpy-Ru pair, and the other populates a lower-energy MLCT state localized on the dpp-Ru pair.
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http://dx.doi.org/10.1021/ic700837u | DOI Listing |
J Chem Theory Comput
January 2025
HUN-REN Wigner Research Centre for Physics, P.O. Box 49, H-1525 Budapest, Hungary.
Chemistry
December 2024
Indian Institute of Technology Kanpur, Chemistry, Department of Chemistry, Indian Institute of Technology Kanpur, 208016, Kanpur, INDIA.
Herein, the photophysical, photochemical properties and photogenerated excited state dynamics of two new Ru(II) complexes, viz. [Ru(p-ttp)(bpy)(PTA)]2+ [1]2+, [Ru(p-ttp)(phen)(PTA)]2+ [2]2+ having a phosphorus-based ligand PTA [p-ttp = p-tolyl terpyridine; bpy = 2,2'-bipyridyl; phen = 1,10-phenthroline and PTA = 1,3,5-triaza-7-phosphaadamantane] are reported. Upon excitation with 470 nm LED, [1]2+ and [2]2+ neither undergo ligand release nor exhibit room temperature luminescence/1O2 generation.
View Article and Find Full Text PDFJ Phys Chem Lett
December 2024
Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States.
Ni 2,2'-bipyridine complexes are commonly invoked intermediates in metallaphotoredox cross-coupling reactions. Despite their ubiquity, design principles targeting improved catalytic performance remain underdetermined. A series of Ni(bpy)(Ar)Cl (R = MeOOC, -Bu, R' = CH, CF) complexes were proposed to have multiconfigurational electronic structures on the basis of multiconfigurational/multireference calculations, with significant mixing of Ni → bpy metal-to-ligand charge transfer (MLCT) configurations into the ground-state wave function.
View Article and Find Full Text PDFFood Chem
December 2024
State Key Lab of Food Science and Resources, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China. Electronic address:
Medium- and long-chain triacylglycerols (MLCTs) have been widely used in the field of pharmaceutical nutrition. However, the application of MLCT as enteral nutrition remains underexplored. Our previous in vitro digestion experiment revealed that MLCTs can improve the bioaccessibility of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in comparison with physically mixed oils (MOs).
View Article and Find Full Text PDFDalton Trans
December 2024
Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via Piero Gobetti 101, 40129 Bologna, Italy.
The 4-methyl-2-(pyridin-2-yl)-2,1-borazaronaphthalene molecule Hazab-py has been successfully used, for the first time, as a ligand in a ruthenium(II) polypyridine complex A (with the formula [Ru(dtbbpy)(azab-py)], where dtbbpy = 4,4'-di--butyl-2,2'-bipyridine). This compound was characterized by NMR spectroscopy and high-resolution mass spectrometry (MS), and its electrochemical and photophysical properties were fully investigated and compared to those of its homoleptic analogue [Ru(dtbbpy)] (B), an archetypical mono-cationic cyclometalated complex C (with the formula [Ru(dtbbpy)(ppy)], where Hppy = 2-phenylpyridine), and the more structurally similar analogue [Ru(dtbbpy)(naft-py)] (D), where the B-N unit of the azaborine ligand is replaced by a standard CC one, resulting in the 2-(naphthalen-2-yl)pyridine ligand (Hnaft-py). The presence of the novel 1,2-azaborine ligand induces a 0.
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