Related Experiment Video
Updated: Sep 23, 2025

Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Structural changes, thermodynamic properties, 1H magic angle spinning NMR, and 14N NMR of (NH4)2CuCl4·2H2O
Ae Ran Lim1,2, Sun Ha Kim3,4
1Analytical Laboratory of Advanced Ferroelectric Crystals, Jeonju University Jeonju 55069 South Korea aeranlim@hanmail.net arlim@jj.ac.kr +82-63-220-2053 +82-63-220-2514.
Abstract:
The structural changes and thermodynamic properties of (NH4)2CuCl4·2H2O were studied by differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis. In addition, the chemical shift, line width, and spin-lattice relaxation time of the crystals were also investigated by 1H magic angle spinning nuclear magnetic resonance (MAS NMR), focusing on the role of NH4 and H2O near the phase transition temperature. The change at T C2 (=406 K) and T C3 (=437 K) seems to be a chemical change caused by thermal decomposition rather than a physical change such as a structural phase transition. The changes in the temperature dependence of these data near T C2 are related to variations in the environments surrounding NH4 and H2O. The 14N NMR spectrum is also measured in order to investigate local phenomena related to the phase transition.
More Related Videos
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
08:55High-Temperature and High-Pressure In situ Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy
Published on: October 9, 2020
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
Colors and Magnetism
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...
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
2D NMR: Overview of Heteronuclear Correlation Techniques