Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Crystal Field Theory - Octahedral Complexes02:58

Crystal Field Theory - Octahedral Complexes

27.9K
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...
27.9K
Spin–Spin Coupling: One-Bond Coupling01:17

Spin–Spin Coupling: One-Bond Coupling

1.1K
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
1.1K
Metal-Ligand Bonds02:51

Metal-Ligand Bonds

21.5K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
21.5K
Crystal Field Theory - Tetrahedral and Square Planar Complexes02:46

Crystal Field Theory - Tetrahedral and Square Planar Complexes

44.7K
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,...
44.7K
Network Covalent Solids02:18

Network Covalent Solids

14.5K
Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
14.5K
Chemical Shift: Internal References and Solvent Effects01:17

Chemical Shift: Internal References and Solvent Effects

769
In an NMR sample, precise measurement of the absolute absorption frequencies of nuclei is difficult. A standard internal reference compound is added, and the frequency difference between the reference signal and sample signals is measured.
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
769

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Elastic Properties of BCN Alloys, Graphene, and <i>h</i>‑BN Monolayers Containing Point Defects.

ACS omega·2026
Same author

Platinum Atoms Dynamics on the Surface of Hexagonal Boron Nitride Containing Vacancy Defects.

ACS applied materials & interfaces·2026
Same author

Stationary Atoms in Liquid Metals and Their Role in Solidification Mechanisms.

ACS nano·2025
Same author

Casimir Force in Layered Materials and Control of the Stable Equilibrium.

The journal of physical chemistry letters·2025
Same author

Atom-by-atom assembly reveals structure-performance control in PdCu catalysts for CO<sub>2</sub> hydrogenation to methanol.

Chemical science·2025
Same author

The Accommodation of Excess Charge in Binary Particle Lattices: A Many-Body Electrostatic Study.

The journal of physical chemistry. B·2025

Related Experiment Video

Updated: Sep 12, 2025

Synthesis of Single-Crystalline Core-Shell Metal-Organic Frameworks
05:26

Synthesis of Single-Crystalline Core-Shell Metal-Organic Frameworks

Published on: February 10, 2023

2.7K

Spin crossover in metal-organic frameworks: A crystal embedded multi-reference study.

I Popov1, A Tchougréeff2, E Besley1

  • 1School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.

The Journal of Chemical Physics
|August 6, 2025
PubMed
Summary
This summary is machine-generated.

The periodic effective Hamiltonian of crystal field (pEHCF) method accurately models spin crossover (SCO) materials. Calculations reveal key factors influencing SCO behavior in Fe(pyridine)2Ni(CN)4 and Fe2(H0.67bdt)3 metal-organic frameworks (MOFs).

More Related Videos

A Technical Guide for Performing Spectroscopic Measurements on Metal-Organic Frameworks
10:13

A Technical Guide for Performing Spectroscopic Measurements on Metal-Organic Frameworks

Published on: April 28, 2023

2.6K
Synthesis and Characterization of Functionalized Metal-organic Frameworks
11:27

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Published on: September 5, 2014

48.3K

Related Experiment Videos

Last Updated: Sep 12, 2025

Synthesis of Single-Crystalline Core-Shell Metal-Organic Frameworks
05:26

Synthesis of Single-Crystalline Core-Shell Metal-Organic Frameworks

Published on: February 10, 2023

2.7K
A Technical Guide for Performing Spectroscopic Measurements on Metal-Organic Frameworks
10:13

A Technical Guide for Performing Spectroscopic Measurements on Metal-Organic Frameworks

Published on: April 28, 2023

2.6K
Synthesis and Characterization of Functionalized Metal-organic Frameworks
11:27

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Published on: September 5, 2014

48.3K

Area of Science:

  • Solid-state chemistry and materials science
  • Computational condensed matter physics
  • Quantum chemistry

Background:

  • Spin crossover (SCO) in transition metal (TM) materials presents computational challenges due to multi-reference electronic states.
  • Accurate electronic structure calculations are crucial for understanding and designing SCO materials.

Purpose of the Study:

  • To apply the periodic effective Hamiltonian of crystal field (pEHCF) method to study SCO in specific metal-organic frameworks (MOFs).
  • To investigate the electronic structure and spin state transitions in Fe(pyridine)2Ni(CN)4 and Fe2(H0.67bdt)3 MOFs.

Main Methods:

  • Utilized the periodic effective Hamiltonian of crystal field (pEHCF) method for electronic structure calculations.
  • Calculated relative energies of spin states and identified degeneracy lines.
  • Analyzed the dependence of spin states on ligand positions and interatomic distances.

Main Results:

  • Identified a degeneracy line in Fe(pyridine)2Ni(CN)4 MOF strongly dependent on Fe-CN distance and showing step-like behavior with pyridine ligand position.
  • Explained the low-temperature paramagnetism of Fe(pyridine)2Ni(CN)4 MOF by Ni's triplet ground state.
  • Confirmed a spin transition from quintet to singlet for Fe2 ions in Fe2(H0.67bdt)3 MOF between 300-423 K, while Fe1 ions remained low-spin.

Conclusions:

  • The pEHCF method is effective for calculating SCO properties in TM-containing crystalline systems.
  • Structural parameters significantly influence SCO behavior in the studied MOFs.
  • The findings provide insights into the mechanisms governing spin crossover in complex materials.