Related Experiment Video
Updated: Jun 25, 2025
10:52
Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
2.7K
Temperature-dependent NIR-CPL spectra of chiral Yb(III) complexes
Annika Sickinger1, Maxime Grasser2, Bruno Baguenard3
1Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie UMR 5182, F-69342 Lyon, France. francois.riobe@icmcb.cnrs.fr.
Physical Chemistry Chemical Physics : PCCP
|May 21, 2024
Summary
Chiral Ytterbium(III) complexes show temperature-dependent circularly polarized luminescence (CPL). New methods allow quantifying CPL contributions from crystal-field split states, crucial for understanding chiral lanthanide materials.
Area of Science:
- Coordination Chemistry
- Materials Science
- Spectroscopy
Background:
- Chiral lanthanide complexes, specifically Ytterbium(III), emit circularly polarized luminescence (CPL) in the near-infrared (NIR) region.
- The CPL is quantified by the dissymmetry factor (g_lum), influenced by crystal-field splitting (CFS) of the excited state.
- Room temperature CPL spectra are complex sums of contributions from multiple Stark sublevels, making quantification difficult.
Purpose of the Study:
- To develop an advanced setup for CPL measurements across a wide temperature range (4 K to 300 K).
- To investigate the temperature-dependent interrelation between crystal-field splitting (CFS), dissymmetry factor (g_lum), and CPL spectra in chiral Yb(III) complexes.
- To elucidate the individual contributions of crystal-field sublevels to the overall CPL spectrum.
Main Methods:
- Development of a specialized apparatus for variable-temperature CPL measurements.
- Synthesis and characterization of enantiopure Yb(III) complexes.
- Spectroscopic analysis of CPL spectra and dissymmetry factors as a function of temperature.
- Computational simulations using multireference wave-functions to interpret spectral contributions.
Main Results:
- Demonstrated strong temperature dependence of CPL spectra and g_lum for chiral Yb(III) complexes.
- Successfully resolved and quantified the contributions of individual Stark sublevels to the overall CPL.
- Experimental findings align with theoretical predictions from multireference wave-function calculations.
Conclusions:
- The CPL of chiral lanthanide complexes is highly sensitive to temperature due to variations in thermal population of crystal-field split sublevels.
- The developed variable-temperature CPL setup provides crucial insights into the fundamental mechanisms governing luminescence in chiral materials.
- This work enables more accurate characterization and design of chiral lanthanide complexes for applications requiring specific CPL properties.
Related Concept Videos
02:24Properties of Enantiomers and Optical Activity
17.0K
It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,...
17.0K
02:58Crystal Field Theory - Octahedral Complexes
26.4K
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...
26.4K
01:20Raman Spectroscopy: Overview
363
The underlying principle of Raman spectroscopy is based on the interaction between light and matter, specifically molecules' inelastic scattering of photons. When a monochromatic beam of light, typically from a laser source, interacts with a sample, most scattered light has the same frequency as the incident light. This is known as Rayleigh scattering.
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and...
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and...
363
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
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
42.4K
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,...
42.4K
01:14Photoluminescence: Applications
387
Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...
387