Related Experiment Video
Updated: Jun 18, 2025
09:33
Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
3.3K
Tracking the conical intersection dynamics for the photoinduced Jahn-Teller switch of a Mn(iii) complex
Ryan Phelps1, Eleftheria Agapaki1, Euan K Brechin1
1EaStCHEM School of Chemistry, University of Edinburgh David Brewster Road EH9 3FJ Edinburgh UK olof.johansson@ed.ac.uk.
Chemical Science
|August 2, 2024
Summary
Researchers explored ultrafast dynamics of manganese(iii) complexes, revealing insights into photoinduced Jahn-Teller switching. This work guides the development of optically controlled single-molecule magnets for ultrafast data storage.
Area of Science:
- * Physical Chemistry
- * Materials Science
- * Quantum Dynamics
Background:
- * Octahedral manganese(iii) ions exhibit Jahn-Teller (JT) distortion, crucial for single-molecule magnets (SMMs).
- * Controlling JT distortion with light offers potential for ultrafast magnetic data storage.
- * The dynamics of photoinduced JT switching, especially at conical intersections, require further investigation.
Purpose of the Study:
- * To elucidate the ultrafast dynamics of the photoinduced Jahn-Teller switch in manganese(iii) complexes.
- * To investigate the vibrational wavepacket motion during and after passage through a conical intersection.
- * To provide insights for designing optically controlled SMMs.
Main Methods:
- * Ultrafast transient absorption spectroscopy was employed.
- * Solutions of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)manganese(iii) (Mn(dpm)3) in ethanol were studied.
- * Analysis focused on vibrational wavepacket generation and propagation on excited and ground state potential energy surfaces.
Main Results:
- * A vibrational wavepacket with a frequency of ~155 cm-1 was observed on the excited state surface, associated with a JT-active mode.
- * Coherent motion persisted through the conical intersection to the ground state, launching wavepackets at ~180 cm-1 (elongated) and ~110 cm-1 (compressed).
- * Phase shifts indicated a one-mode reaction coordinate and passage through the conical intersection at specific fractions of the vibrational period.
Conclusions:
- * Direct insights into the non-adiabatic dynamics of Mn(iii) complexes during photoinduced JT switching were obtained.
- * The study clarifies the role of vibrational wavepackets and conical intersections in the switching mechanism.
- * Findings will guide the rational design of single-molecule magnets controllable by light for advanced data storage applications.
Related Concept Videos
03:02Colors and Magnetism
11.6K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
11.6K
02:58Crystal Field Theory - Octahedral Complexes
26.3K
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...
26.3K
02:42Valence Bond Theory
8.5K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
8.5K
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
990
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
990
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
41.9K
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,...
41.9K
02:52Stereoisomerism
11.8K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
11.8K