Experimental Spin State Determination of Iron(II) Complexes by Hirshfeld Atom Refinement
Daniel Brüx1, Ben Ebel1, Niklas Pelzer1
1Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074, Aachen, Germany.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|December 23, 2024
Summary
This study introduces Hirshfeld Atom Refinement for determining transition metal complex spin states. The method successfully distinguishes high-spin from low-spin configurations in iron complexes.
Area of Science:
- Inorganic Chemistry
- Crystallography
- Computational Chemistry
Background:
- Determining the spin state of transition metal complexes is crucial for understanding their properties.
- Experimental methods for spin state determination can be challenging, especially for spin-crossover compounds.
Purpose of the Study:
- To present the first experimental determination of spin states in transition metal complexes using Hirshfeld Atom Refinement.
- To demonstrate the efficacy of Hirshfeld Atom Refinement in distinguishing between high-spin and low-spin states.
Main Methods:
- Utilized Hirshfeld Atom Refinement (HAR) for experimental spin state determination.
- Investigated two iron(II) complexes: (NH4)2Fe(SO4)2 · 6 H2O and [Fe(pic)3]Cl2 · EtOH.
- Refined crystal structures using wavefunctions of different spin multiplicities and analyzed refinement indicators and residual electron density.
Main Results:
- Hirshfeld Atom Refinement clearly distinguished between high-spin and low-spin configurations in the investigated iron complexes.
- The method proved effective even for compounds exhibiting spin-crossover behavior.
- Successful experimental determination of spin states was achieved.
Conclusions:
- Hirshfeld Atom Refinement is a viable and powerful method for experimentally determining spin states in transition metal complexes.
- This technique offers a new approach for characterizing the electronic properties of metal complexes.
- The study highlights the potential of HAR in advancing the field of inorganic chemistry.
Keywords:
Hirshfeld Atom RefinementIronSolid-state structuresSpin state determinationX-ray diffractionMore Related Videos
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
8.5K
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.0K
Related Concept Videos
03:02Colors and Magnetism
11.5K
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...
11.5K
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
01:03Atomic Nuclei: Nuclear Spin State Overview
866
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
866
02:58Crystal Field Theory - Octahedral Complexes
26.1K
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...
26.1K
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.0K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.0K
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
938
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
938