Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Valence Bond Theory

Valence 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...

Metal-Ligand Bonds

Metal-Ligand Bonds

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...

Crystal Field Theory - Octahedral Complexes

Crystal 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...

Complexation Equilibria: The Chelate Effect

Complexation Equilibria: The Chelate Effect

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...

Structural Isomerism

Structural Isomerism

Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...

Colors and Magnetism

Colors 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.

You might also read

Related Articles

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

Sort by

Same author

Synergistic Surface Copassivation of PbS Colloidal Quantum Dot Films for Efficient Inverted Solar Cells.

ACS applied materials & interfaces·2026

Same author

An entropy-regulating molecular lock stabilizes formamidinium lead halide perovskite.

Science (New York, N.Y.)·2026

Same author

Advancements in Self-Assembled Molecules to Hybrid Self-Assembled Molecular Interlayers for Optimized Hole Transport Layer in Inverted Perovskite Solar Cells.

Small (Weinheim an der Bergstrasse, Germany)·2025

Same author

Theoretical modeling of interactions of Cr<sub>2</sub>O<sub>n</sub> and Mn<sub>2</sub>O<sub>n</sub> clusters with H<sub>2</sub> molecules.

Journal of molecular modeling·2025

Same author

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones.

Beilstein journal of organic chemistry·2025

Same author

Cryostructuring of Polymeric Systems: 68. Evaluation of Poly(vinyl alcohol) Composite Cryogels Filled with Poly(3-hydroxybutyric acid)-Based Microspheres of Different Porous Morphology as Potential Delivery Systems for Drugs of Various Water-Solubility.

Gels (Basel, Switzerland)·2024

Search research articles

Related Experiment Video

Updated: Jul 20, 2026

Synthesis of a Thiol Building Block for the Crystallization of a Semiconducting Gyroidal Metal-sulfur Framework

Synthesis of a Thiol Building Block for the Crystallization of a Semiconducting Gyroidal Metal-sulfur Framework

Published on: April 9, 2018

Dinitrosyl-iron complexes with thiol-containing ligands: spatial and electronic structures.

Anatoly F Vanin¹, Natalia A Sanina, Vladimir A Serezhenkov

¹Semenov Institute of Chemical Physics, Russian Academy of Sciences, Russian Federation. vanin@polymer.chph.ras.ru <vanin@polymer.chph.ras.ru>

Nitric Oxide : Biology and Chemistry

|September 19, 2006

Summary

Dinitrosyl-iron complexes with 1H-1,2,4-triazole-3-thiol (DNIC-MT) exhibit distinct Electron Paramagnetic Resonance (EPR) signals in solution versus crystalline states. This difference is attributed to structural and electronic configuration changes, impacting their interactions.

More Related Videos

Preparation of SNS Cobalt(II) Pincer Model Complexes of Liver Alcohol Dehydrogenase

Preparation of SNS Cobalt(II) Pincer Model Complexes of Liver Alcohol Dehydrogenase

Published on: March 19, 2020

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyl(tropone)iron

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyl(tropone)iron

Published on: August 12, 2019

Related Experiment Videos

Last Updated: Jul 20, 2026

Synthesis of a Thiol Building Block for the Crystallization of a Semiconducting Gyroidal Metal-sulfur Framework

Synthesis of a Thiol Building Block for the Crystallization of a Semiconducting Gyroidal Metal-sulfur Framework

Published on: April 9, 2018

Preparation of SNS Cobalt(II) Pincer Model Complexes of Liver Alcohol Dehydrogenase

Preparation of SNS Cobalt(II) Pincer Model Complexes of Liver Alcohol Dehydrogenase

Published on: March 19, 2020

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyl(tropone)iron

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyl(tropone)iron

Published on: August 12, 2019

Area of Science:

Coordination Chemistry
Biophysical Chemistry
Materials Science

Background:

Dinitrosyl-iron complexes (DNICs) are crucial in biological systems and chemical synthesis.
The ligand 1H-1,2,4-triazole-3-thiol (MT) forms stable DNICs with unique properties.
Understanding the structural and electronic states of DNICs is key to their applications.

Purpose of the Study:

To compare the Electron Paramagnetic Resonance (EPR) signal parameters of monomeric DNIC-MT in solution and crystalline states.
To elucidate the structural and electronic transitions of DNIC-MT upon dissolution.
To investigate the role of exchange interactions in crystalline DNIC-MT.

Main Methods:

Synthesis of DNIC-MT by reacting MT, ferrous iron, and nitric oxide (NO) in DMSO.
Characterization using Electron Paramagnetic Resonance (EPR) spectroscopy at ambient and cryogenic temperatures.
Analysis of EPR signal shapes, hyperfine structures, and g-values for both solution and crystalline samples.

Main Results:

Solution DNIC-MT shows isotropic EPR signals (g=2.03) with quintet hyperfine structure or anisotropic signals (g⊥=2.045, g∥=2.014) at 77 K.
Crystalline DNIC-MT exhibits a structure-less singlet EPR signal (g=2.03, 1.7 mT width) indicating strong exchange interactions.
Dissolution of crystalline DNIC-MT yields solution-type EPR signals, suggesting a transformation from tetrahedral d(9) to planar-square d(7) configurations.

Conclusions:

The EPR spectral differences reflect a structural change from tetrahedral to planar-square geometry upon DNIC-MT dissolution.
The d(9) to d(7) electronic configuration change is responsible for the distinct EPR signals observed.
DNIC formation may involve NO ionization, and exchange interactions are significant in the crystalline state.