Related Experiment Video
Updated: Jul 9, 2025
10:57
Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
18.2K
Catalyzing Singlet Fission by Transition Metals: Second versus Third Row Effects.
Yuxuan Hou1, Ilias Papadopoulos2, Yifan Bo2
1Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada.
Precision Chemistry
|December 1, 2023
Summary
Platinum and palladium complexes with pentacene ligands undergo intramolecular singlet fission (iSF), generating triplet pairs. The mechanism of iSF differs between platinum(II) and palladium(II) centers, influenced by metal properties.
Area of Science:
- Inorganic Chemistry
- Photochemistry
- Materials Science
Background:
- Platinum(II) and palladium(II) complexes are synthesized with varying numbers of pentacene-based pyridyl ligands.
- Photophysical properties are investigated to understand intramolecular singlet fission (iSF) in these metal complexes.
Purpose of the Study:
- To characterize platinum(II) and palladium(II) complexes with pentacene ligands.
- To investigate the mechanism and efficiency of intramolecular singlet fission (iSF) in these complexes.
- To compare the photophysical behavior of platinum(II) and palladium(II) dimers.
Main Methods:
- Synthesis and characterization of platinum(II) and palladium(II) complexes.
- Steady-state and time-resolved transient absorption spectroscopy.
- Solvent-dependent studies to probe charge transfer and polarity effects.
Main Results:
- Intramolecular singlet fission (iSF) occurs efficiently, yielding triplet pairs, and is not hindered by intersystem crossing.
- Platinum(II) dimers show a direct iSF pathway forming correlated triplet pairs within 10 ns.
- Palladium(II) dimers exhibit solvent-dependent charge transfer mixing and a stable equilibrium of correlated triplet pairs with longer lifetimes (up to 170 ns).
Conclusions:
- The metal center (Pt(II) vs. Pd(II)) significantly alters the iSF mechanism.
- Differences in metal size and polarizability are key factors influencing the observed photophysical trends.
- Pentacene ligand separation facilitates chromophore decoupling and triplet pair generation.
More Related Videos
Related Concept Videos
02:58Properties of Transition Metals
26.0K
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
26.0K
04:00Periodic Classification of the Elements
45.6K
The periodic table arranges atoms based on increasing atomic number so that elements with the same chemical properties recur periodically. When their electron configurations are added to the table, a periodic recurrence of similar electron configurations in the outer shells of these elements is observed. Because they are in the outer shells of an atom, valence electrons play the most important role in chemical reactions. The outer electrons have the highest energy of the electrons in an atom...
45.6K
02:50Nuclear Fission
9.7K
Many heavier elements with smaller binding energies per nucleon can decompose into more stable elements that have intermediate mass numbers and larger binding energies per nucleon—that is, mass numbers and binding energies per nucleon that are closer to the “peak” of the binding energy graph near 56. Sometimes neutrons are also produced. This decomposition of a large nucleus into smaller pieces is called fission. The breaking is rather random with the formation of a large...
9.7K
03:51Molecular Orbital Theory II
19.2K
Molecular Orbital Energy Diagrams
19.2K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
42.7K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
42.7K
02:58Crystal Field Theory - Octahedral Complexes
26.6K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
26.6K