Adjusting the Coordination Configuration by Changing Electrostatic Potential: Introducing N/O/S Heteroatoms Based on
Chao Zhang1, Tingwei Wang2, Shaoqun Li1
1State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
The Journal of Organic Chemistry
|November 20, 2024
Summary
This study synthesized three silver-based energetic coordination compounds (ECCs) with modified ligands. The imidazole-based ECC showed reduced sensitivity, while oxazole and thiazole variants demonstrated enhanced detonation performance and thermal stability, respectively.
Area of Science:
- Coordination Chemistry
- Energetic Materials Science
- Materials Chemistry
Background:
- Energetic coordination compounds (ECCs) offer tunable properties via organic ligand design.
- Ligand modification alters electron density, influencing coordination and material characteristics.
- Understanding structure-property relationships is key for developing advanced energetic materials.
Purpose of the Study:
- To investigate the impact of heterocyclic ligands (imidazole, oxazole, thiazole) on the properties of AgClO4-based ECCs.
- To correlate structural features with energetic performance, including sensitivity, detonation properties, and thermal stability.
- To evaluate the initiation capabilities of synthesized ECCs.
Main Methods:
- Computational analysis (Mulliken charge, electrostatic potential) to study ligand effects on electron density.
- Synthesis of three AgClO4-based ECCs using carbohydrazide derivatives.
- Single-crystal X-ray diffraction for structural determination (1D chain vs. 0D structures).
- Evaluation of mechanical sensitivity, oxygen balance, detonation parameters, thermal stability, and initiation tests.
Main Results:
- Synthesized [Ag(IZ-4-CA)ClO4], Ag2(OZCA)2(ClO4)2, and Ag2(SZCA)2(ClO4)2.
- [Ag(IZ-4-CA)ClO4] exhibited a 1D chain structure with low mechanical sensitivity (IS = 21 J, FS = 80 N).
- Ag2(OZCA)2(ClO4)2 showed enhanced oxygen balance, leading to high predicted detonation velocity (6.4 km s-1) and pressure (23.6 GPa).
- Ag2(SZCA)2(ClO4)2 displayed the highest initial decomposition temperature (232 °C).
- All three ECCs demonstrated successful detonation of RDX.
Conclusions:
- Ligand structure significantly influences ECC properties, including dimensionality, sensitivity, and energetic performance.
- The 1D chain structure of [Ag(IZ-4-CA)ClO4] contributes to its reduced sensitivity.
- Oxazole and thiazole moieties can be strategically employed to enhance detonation performance and thermal stability, respectively.
- These ECCs show promise as initiators due to their ability to detonate RDX.
More Related Videos
06:53Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
1.9K
14:44Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
9.6K
Related Concept Videos
02:42Valence Bond Theory
8.5K
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...
8.5K
02:34Structural Isomerism
19.1K
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...
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...
19.1K
02:58Crystal Field Theory - Octahedral Complexes
26.2K
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...
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...
26.2K
02:54Coordination Compounds and Nomenclature
21.2K
In most main group element compounds, the valence electrons of the isolated atoms combine to form chemical bonds that satisfy the octet rule. For instance, the four valence electrons of carbon overlap with electrons from four hydrogen atoms to form CH4. The one valence electron leaves sodium and adds to the seven valence electrons of chlorine to form the ionic formula unit NaCl (Figure 1a). Transition metals do not normally bond in this fashion. They primarily form coordinate covalent bonds, a...
21.2K
02:57Coordination Number and Geometry
15.5K
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
15.5K