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Published on: April 14, 2020
Two novel Cu(II) diphosphonates: structural, spectral and magnetic studies
Kui-Rong Ma1, Yu Zhang, Yu-He Kan
1Jiangsu Key Laboratory for Chemistry of Low-dimensional Materials, School of Chemistry and Chemical Engineering, Huaiyin Normal University, Huaian 223300, PR China. kuirongma@163.com
Summary
New copper(II) coordination polymers using diphosphonate ligands and N-heterocyclic ligands (2,2-bipyridine or phenanthroline) were synthesized. These materials exhibit distinct zero-dimensional structures with interesting magnetic and fluorescent properties.
Area of Science:
- Inorganic Chemistry
- Materials Science
- Supramolecular Chemistry
Background:
- Coordination polymers are versatile materials with tunable properties.
- Diphosphonate ligands offer diverse coordination modes.
- N-heterocyclic ligands can influence the structure and properties of metal complexes.
Purpose of the Study:
- To synthesize and characterize novel copper(II)-diphosphonate coordination polymers.
- To investigate the structural, magnetic, and fluorescent properties of the synthesized compounds.
- To explore the role of N-heterocyclic ligands in dictating the coordination polymer architecture.
Main Methods:
- Solvothermal synthesis.
- Powder and single-crystal X-ray diffraction.
- Elemental analysis, IR spectroscopy, Thermogravimetric analysis (TG-DSC).
- Fluorescent spectroscopy and magnetic susceptibility measurements.
Main Results:
- Two zero-dimensional copper(II)-diphosphonate coordination polymers, [Cu(H4L)2(2,2'-bipy)]·H2O (1) and [Cu(H3L)(phen)]2·(HOCH2CH2OH)0.5 (2), were successfully synthesized.
- Compound 1 features a mononuclear [CuO4N2] unit, while compound 2 exhibits a binuclear [-Cu-O-P-O-] unit with syn-anti bridging.
- Both compounds form 3D supramolecular frameworks via hydrogen bonding and π-π interactions.
- Fluorescence emissions were observed around 434 nm, attributed to intraligand π-π transitions.
- Compound 1 displays antiferromagnetic behavior, whereas compound 2 shows ferromagnetic behavior.
Conclusions:
- The choice of N-heterocyclic ligand (2,2'-bipyridine or 1,10-phenanthroline) influences the nuclearity and structure of the copper(II)-diphosphonate coordination polymers.
- The synthesized coordination polymers possess interesting photophysical and magnetic properties.
- These findings contribute to the development of novel functional coordination materials.
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