Related Experiment Video
Updated: May 7, 2026
10:51
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
First-principles electronic structure study of rhizoferrin and its Fe(III) complexes.
1Department of Physics and Astronomy, University of Central Florida, Orlando, FL, USA.
Summary
Rhizoferrin (Rf), a siderophore, forms stable iron(III) complexes with octahedral coordination. Density functional theory calculations reveal a low-spin, neutral chiral complex with high binding energy, predicting NMR parameters for future experiments.
Area of Science:
- Computational chemistry
- Biochemistry
- Inorganic chemistry
Background:
- Rhizoferrin (Rf) is a siderophore crucial for iron uptake in biological systems.
- Understanding the coordination chemistry of Rf with Fe(III) is vital for its biological function.
- Siderophores play a key role in iron bioavailability and microbial interactions.
Purpose of the Study:
- To determine the structure and coordination chemistry of rhizoferrin (Rf) and its Fe(III) complexes.
- To investigate the binding energy and properties of different Fe(III)-Rf complexes.
- To calculate and predict spectroscopic parameters for Rf and its Fe(III) complexes.
Main Methods:
- Density functional theory (DFT) calculations were employed.
- Structural and coordination properties of Rf-Fe(III) complexes were analyzed.
- Nuclear magnetic resonance (NMR) parameters (chemical shifts, spin-spin couplings) and nuclear quadrupole interaction (NQI) parameters were computed.
Main Results:
- The Fe(III) ion exhibits octahedral coordination within the Rf complex.
- A low-spin (S = 1/2), charge-neutral, chiral complex demonstrated the highest binding energy.
- Calculated chemical shifts for free Rf show excellent agreement with experimental data.
- Predicted NMR and NQI parameters for Fe(III) complexes are provided.
Conclusions:
- DFT calculations provide insights into the coordination chemistry of rhizoferrin with Fe(III).
- The study identifies a highly stable Fe(III)-Rf complex.
- The calculated spectroscopic parameters serve as predictions for future experimental validation.
More Related Videos
Related Concept Videos
02:58Crystal Field Theory - Octahedral Complexes
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...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
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,...
03:45Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
01:24Microbes and Other Elemental Cycles
Microbial activity plays a pivotal role in the biogeochemical cycling of iron and manganese, especially at the redox gradients characteristic of stratified aquatic environments. These cycles are driven by microbial transformations between oxidized and reduced forms of the metals, allowing organisms to exploit them for metabolic energy and structural purposes.Iron Cycling Across Redox GradientsIn neutral, oxygen-rich surface waters, iron is predominantly found in its oxidized, insoluble ferric...
03:02Colors and Magnetism
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 eye.
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 eye.
02:42Valence Bond Theory
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...