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

Colors and Magnetism03:02

Colors and Magnetism

12.3K
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...
12.3K
Valence Bond Theory02:42

Valence Bond Theory

9.1K
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...
9.1K
Crystal Field Theory - Octahedral Complexes02:58

Crystal Field Theory - Octahedral Complexes

27.4K
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...
27.4K
Crystal Field Theory - Tetrahedral and Square Planar Complexes02:46

Crystal Field Theory - Tetrahedral and Square Planar Complexes

44.1K
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,...
44.1K
Formation of Complex Ions03:45

Formation of Complex Ions

24.0K
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...
24.0K
Complexation Equilibria: The Chelate Effect01:19

Complexation Equilibria: The Chelate Effect

644
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
644

You might also read

Related Articles

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

Sort by
Same author

Nature of Cr-NO Bonding from <sup>15</sup>N Solid-State NMR and X-ray Absorption Spectroscopic Signatures.

Journal of the American Chemical Society·2026
Same author

Unexpected pyrazine ring annulation in the Cu-catalyzed reaction of aryl bromides with 1,2-diamines. Synthesis of novel pyrazino[2,3-<i>f</i>]perimidine fluorophores.

Organic & biomolecular chemistry·2026
Same author

Synthesis and Characterization of Free and Coordinated Nitroxide and Nitronyl Nitroxide Diradicals with a 2,7-Naphthalene Coupling Unit.

Inorganic chemistry·2026
Same author

Zinc(II) Coordination Compounds on Acylhydrazones of 2-Tosylaminobenzaldehyde Basis as Promising Luminescent Agents.

International journal of molecular sciences·2026
Same author

DeepFit: Physically and Chemically Informed XAS-Structure Fitting Made Simple.

The journal of physical chemistry letters·2026
Same author

Monomeric Fluorescence of H-Aggregates in a Series of 2-(Hydroxyphenyl)benzoxazoles Derivatives.

Chemistry (Weinheim an der Bergstrasse, Germany)·2026

Related Experiment Video

Updated: Sep 5, 2025

Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
06:53

Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks

Published on: June 9, 2023

2.1K

Spin transitions in ferric catecholate complexes mediated by outer-sphere counteranions.

Maxim Chegerev1, Oleg Demidov2, Pavel Vasilyev3

  • 1Institute of Physical and Organic Chemistry, Southern Federal University, Stachki Avenue, 194/2, 344090, Rostov-on-Don, Russia. mchegerev@sfedu.ru.

Dalton Transactions (Cambridge, England : 2003)
|July 6, 2022
PubMed
Summary
This summary is machine-generated.

Researchers synthesized ferric catecholate complexes with varying counteranions, observing spin transitions. Compound 4 uniquely exhibited valence tautomerism alongside spin-crossover, marking a first for mononuclear ferric catecholate complexes.

More Related Videos

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
11:19

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels

Published on: July 4, 2016

10.7K
Synthesis of Cationized Magnetoferritin for Ultra-fast Magnetization of Cells
10:23

Synthesis of Cationized Magnetoferritin for Ultra-fast Magnetization of Cells

Published on: December 13, 2016

10.0K

Related Experiment Videos

Last Updated: Sep 5, 2025

Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
06:53

Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks

Published on: June 9, 2023

2.1K
Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
11:19

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels

Published on: July 4, 2016

10.7K
Synthesis of Cationized Magnetoferritin for Ultra-fast Magnetization of Cells
10:23

Synthesis of Cationized Magnetoferritin for Ultra-fast Magnetization of Cells

Published on: December 13, 2016

10.0K

Area of Science:

  • Coordination Chemistry
  • Materials Science
  • Magnetochemistry

Background:

  • Ionic ferric catecholate complexes are of interest for their magnetic properties.
  • Spin crossover phenomena in transition metal complexes are tunable via ligand and counteranion modifications.

Purpose of the Study:

  • To synthesize and characterize a series of ionic ferric catecholate complexes with a 3,6-di-tert-butyl-catecholate ligand and a tris(2-pyridylmethyl)amine ligand.
  • To investigate the spin transition behavior of these complexes as a function of outer-sphere counteranions.
  • To explore the potential for coupled spin-crossover and valence tautomerism.

Main Methods:

  • Synthesis of four novel ionic ferric catecholate complexes.
  • Single crystal X-ray diffraction at 100 K and 293 K.
  • Comprehensive spectroscopic characterization including EPR, magnetic susceptibility, Mössbauer spectroscopy, and X-ray absorption spectroscopy (XAS).

Main Results:

  • All synthesized complexes (1-4) exhibited thermally induced spin-crossover in the solid state, with varying degrees of completeness.
  • The magnetic behavior was influenced by the nature of the outer-sphere counteranions (PF6, BPh4, ClO4, BF4).
  • Complex 4, featuring BF4 anions, displayed a unique valence tautomeric transition coupled with spin-crossover, a first for this class of compounds.

Conclusions:

  • The counteranion plays a crucial role in modulating the spin transition properties of ferric catecholate complexes.
  • Compound 4 represents a novel example of a mononuclear ferric catecholate complex exhibiting coupled spin-crossover and valence tautomerism.
  • This discovery opens new avenues for designing functional materials with switchable electronic and magnetic properties.