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

Spin–Spin Coupling: One-Bond Coupling01:17

Spin–Spin Coupling: One-Bond Coupling

1.6K
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,...
1.6K
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)01:20

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

1.9K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.9K
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)01:22

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)

1.7K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
1.7K
Valence Bond Theory02:42

Valence Bond Theory

11.7K
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...
11.7K
Spin–Spin Coupling Constant: Overview01:08

Spin–Spin Coupling Constant: Overview

1.6K
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
1.6K
Woodward–Hoffmann Selection Rules and Microscopic Reversibility01:34

Woodward–Hoffmann Selection Rules and Microscopic Reversibility

4.2K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
4.2K

You might also read

Related Articles

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

Sort by
Same author

An effect of scandium substitution on the phase purity and structural, magnetic, and electrochemical features of ε-Fe<sub>2</sub>O<sub>3</sub> nanoparticle systems.

Nanoscale·2022
Same author

Retraction Note: Air-stable superparamagnetic metal nanoparticles entrapped in graphene oxide matrix.

Nature communications·2020
Same author

Smart synthetic maghemite nanoparticles with unique surface properties encode binding specificity toward As<sup>III</sup>.

The Science of the total environment·2020
Same author

Corrigendum: An Isolated Molecule of Iron(II) Phthalocyanin Exhibits Quintet Ground-State: A Nexus between Theory and Experiment.

Chemistry (Weinheim an der Bergstrasse, Germany)·2020
Same author

Activation of α-Fe<sub>2</sub> O<sub>3</sub> for Photoelectrochemical Water Splitting Strongly Enhanced by Low Temperature Annealing in Low Oxygen Containing Ambient.

Chemistry (Weinheim an der Bergstrasse, Germany)·2019
Same author

Spin-Crossover Phenomenon in Microcrystals and Nanoparticles of a [Fe(2-mpz)<sub>2</sub>Ni(CN)<sub>4</sub>] Two-Dimensional Hofmann-Type Polymer: A Detailed Nano-Topographic Study.

Inorganic chemistry·2019

Related Experiment Video

Updated: Apr 5, 2026

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

3.5K

Hysteretic Spin Crossover in Two-Dimensional (2D) Hofmann-Type Coordination Polymers.

Wei Liu1, Lu Wang1, Yu-Jun Su1

  • 1Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, People's Republic of China.

Inorganic Chemistry
|August 11, 2015
PubMed
Summary

Researchers synthesized novel 2D coordination polymers exhibiting cooperative spin crossover (SCO). These materials display significant magnetic hysteresis, crucial for potential memory device applications.

More Related Videos

HKUST-1 as a Heterogeneous Catalyst for the Synthesis of Vanillin
11:15

HKUST-1 as a Heterogeneous Catalyst for the Synthesis of Vanillin

Published on: July 23, 2016

10.8K
Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
14:44

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR

Published on: December 16, 2013

10.2K

Related Experiment Videos

Last Updated: Apr 5, 2026

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

3.5K
HKUST-1 as a Heterogeneous Catalyst for the Synthesis of Vanillin
11:15

HKUST-1 as a Heterogeneous Catalyst for the Synthesis of Vanillin

Published on: July 23, 2016

10.8K
Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
14:44

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR

Published on: December 16, 2013

10.2K

Area of Science:

  • Materials Science
  • Inorganic Chemistry
  • Solid-State Chemistry

Background:

  • Two-dimensional (2D) coordination polymers offer unique structural and electronic properties.
  • Spin crossover (SCO) materials are of interest for molecular switches and memory devices.
  • Hofmann-type coordination polymers provide a versatile framework for designing functional materials.

Purpose of the Study:

  • To synthesize and characterize novel 2D Hofmann-type coordination polymers.
  • To investigate the spin crossover properties and magnetic behaviors of these new compounds.
  • To elucidate the structural factors influencing cooperativity and hysteresis in SCO materials.

Main Methods:

  • Synthesis of three new 2D Hofmann-type coordination polymers: [Fe(3-NH2py)2M(CN)4] where M = Ni (1), Pd (2), Pt (3).
  • Magnetic susceptibility measurements to determine spin crossover (SCO) behavior and hysteresis.
  • Single-crystal X-ray diffraction analysis of compound 1 to determine its crystal structure.

Main Results:

  • Successful synthesis of three new 2D Hofmann-type coordination polymers.
  • Observation of cooperative spin crossover (SCO) with significant magnetic hysteresis in all three compounds.
  • Hysteresis widths of 25 K, 37 K, and 30 K for compounds 1, 2, and 3, respectively.
  • Structural analysis revealed 2D grids formed by Fe sites bridged by [M(CN)4](2-) and coordinated by 3-aminopyridine (3-NH2py) ligands.

Conclusions:

  • The synthesized 2D coordination polymers exhibit cooperative spin crossover with notable hysteretic behavior.
  • Intermolecular interactions, including π–π stacking, hydrogen bonds, and N(amino)···Ni(II) contacts, alongside covalent bridging, contribute to significant cooperativity.
  • These findings highlight the potential of these materials for applications in molecular electronics and data storage.