Novel photocatalysts based on ruthenium complexes with NHC (N-heterocyclic carbene)-type bridging ligands have been prepared and structurally and photophysically characterised. The identity of the NHC-unit of the bridging ligand was established unambiguously by means of X-ray structural analysis of a heterodinuclear ruthenium-silver complex. The photophysical data indicate ultrafast intersystem crossing into an emissive and a non-emissive triplet excited state after excitation of the ruthenium centre. Exceptionally high luminescence quantum yields of up to 39% and long lifetimes of up to 2 μs are some of the triplet excited state characteristics. Preliminary studies into the visible light driven photocatalytic hydrogen formation show no induction phase and constant turnover frequencies that are independent on the concentration of the photocatalyst. In conclusion this supports the notion of a stable assembly under photocatalytic conditions.
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http://dx.doi.org/10.1039/c4dt01546k | DOI Listing |
Molecules
December 2024
Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China.
Endohedral metallo-borospherenes M@B have received considerable attention since the discovery of B in 2014. However, the coordination bonding nature of most of actinide-doped endohedral An@B still remains in dispute or unexplored. Extensive and systematic first-principles theory calculations performed herein unveil the ground states of triplet U@B (, , A), quartet U@B (, , B), quintet Np@B (, , A), sextet Np@B (, , A), septet Pu@B (, , A), octet Am@B (, , A), and octet Cm@B (, , A) at the coupled-cluster with triple excitations CCSD(T) level.
View Article and Find Full Text PDFNPJ Quantum Mater
January 2025
NIST Center for Neutron Research, Gaithersburg, MD 20899 USA.
The detailed anisotropic dispersion of the low-temperature, low-energy magnetic excitations of the candidate spin-triplet superconductor UTe is revealed using inelastic neutron scattering. The magnetic excitations emerge from the Brillouin zone boundary at the high symmetry and points and disperse along the crystallographic -axis. In applied magnetic fields to at least = 11 T along the , the magnetism is found to be field-independent in the ( 0) plane.
View Article and Find Full Text PDFChemistry
January 2025
Shandong University, School of Chemistry and Chemical Engineering, 27 Shanda Nan Road, 250100, Jinan, CHINA.
Photophysical properties of condensed systems generally originate from collective contributions of all components in their stochastically fluctuated structures and are strongly influenced under strain of chromophores. To precisely identify how the stochastically fluctuated monomers synergistically manipulate the properties, we propose a statistic strategy over sufficient ab initio molecular dynamics (AIMD) samplings and for the first time uncover that synergistic oscillatory twisting (SOT) of neighboring under-strain monomers manipulates the bifunction of rubrene crystal. The under-strain trunk SOT can regulate both singlet fission (SF) and triplet-triplet annihilation (TTA), enabling their coexistence and dominance switching by dynamically modulating the matching of excitation energies.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Road, Winnipeg, Manitoba R3T 2N2, Canada.
The ability to manipulate excited-state decay cascades using molecular structure is essential to the application of abundant-metal photosensitizers and chromophores. Ligand design has yielded some spectacular results elongating charge-transfer excited state lifetimes of Fe(II) coordination complexes, but triplet metal-centered (MC) excited states─recently demonstrated to be critical to the photoactivity of isoelectronic Co(III) polypyridyls─have to date remained elusive, with temporally isolable examples limited to the picosecond regime. With this report, we show how strong-field donors and intramolecular π-stacking can conspire to stabilize a long-lived MC excited state for a remarkable 4.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Department of Chemistry, The University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States.
ConspectusLight-driven polymerizations and their application in 3D printing have revolutionized manufacturing across diverse sectors, from healthcare to fine arts. Despite the popularized notion that with 3D printing "imagination is the only limit", we and others in the scientific community have identified fundamental hurdles that restrict our capabilities in this space. Herein, we describe the group's efforts in developing photochemical systems that respond to nontraditional colors of light to elicit the rapid, spatiotemporally controlled formation of plastics.
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