Related Experiment Video
Updated: May 15, 2026
06:35
Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Low-dimensional 3d-4f complexes assembled by low-spin [Fe(III)(phen)(CN)4]- anions
Diana Visinescu1, Luminita Marilena Toma, Oscar Fabelo
1Coordination and Supramolecular Chemistry Laboratory, Institute of Physical Chemistry Ilie Murgulescu, Romanian Academy, Splaiul Independentei 202, 060021 Bucharest, Romania. diana.visinescu@gmail.com
Inorganic Chemistry
|January 22, 2013
Summary
This study synthesized new mixed 3d-4f metal complexes. Magnetic susceptibility measurements revealed antiferromagnetic interactions in one complex and weak ferromagnetic interactions in another, with minimal interactions in the remaining two.
Area of Science:
- Coordination Chemistry
- Materials Science
- Magnetochemistry
Background:
- Mixed 3d-4f metal complexes are of interest for their unique structural and magnetic properties.
- Understanding the interplay between different metal ions and bridging ligands is crucial for designing novel magnetic materials.
Purpose of the Study:
- To synthesize and characterize novel mixed 3d-4f complexes incorporating iron(III) and rare-earth metals (Gd, Tb, Sm, Pr).
- To investigate the crystal structures and magnetic properties of these newly synthesized compounds.
Main Methods:
- Synthesis of four new mixed 3d-4f complexes: [{Fe(III)(phen)(CN)(4)}(4)Gd(2)(III)(bpym)(NO(3))(2)(H(2)O)(4)]·2CH(3)CN·2H(2)O}(n) (1), [{Fe(III)(phen)(CN)(4)}(4)Tb(2)(III)(bpym)(H(2)O)(8)]·(NO(3))(2)·2CH(3)CN}(n) (2), [{Fe(III)(phen)(CN)(4)}(4)Sm(III)(bpym)(NO(3))(2)(H(2)O)(5)]·2CH(3)CN}(n) (3), and [{Fe(III)(phen)(CN)(4)}(2)Pr(2)(III)(bpym)()(NO(3))(4)(H(2)O)(2)](n) (4).
- X-ray crystallography to determine the detailed crystal structures, revealing ladder-like motifs (1-3) and a 2D structure (4).
- Magnetic susceptibility measurements conducted over a temperature range of 1.9-300 K to probe magnetic interactions.
Main Results:
- Compounds 1-3 are isomorphous, featuring ladder-like structures with bpym-bridged dilanthanide(III) cations and [Fe(phen)(CN)(4)](-) units.
- Compound 4 exhibits a neutral two-dimensional structure with interlinked [Fe(phen)(CN)(4)](-) units.
- Magnetic studies indicated antiferromagnetic interactions in complex 1, weak ferromagnetic interactions in complex 3, and very weak interactions in complexes 2 and 4.
Conclusions:
- The synthesized mixed 3d-4f complexes display diverse structural architectures.
- The magnetic properties are influenced by the bridging ligands (cyanide and bpym) and the specific rare-earth ion.
- The observed magnetic interactions provide insights into the magnetic coupling mechanisms in these polynuclear coordination compounds.
Related Concept Videos
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...
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.
02:42Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
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,...
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...
02:57Coordination Number and Geometry
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.