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![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
Published on: May 21, 2019
Chloro-cobalt complexes with pyridyl-ethyl-derived di-aza-cyclo-alkanes
Anthony W Addison1, Stephen J Jaworski1, Jerry P Jasinski2
1Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA.
New cobalt(II) chloride complexes with tetra-dentate ligands were synthesized. These complexes exhibit dinuclear and mononuclear structures, with varying coordination geometries and electronic properties.
Area of Science:
- Coordination Chemistry
- Inorganic Synthesis
- Materials Science
Background:
- Cobalt(II) chloride complexes with nitrogen-containing ligands are of interest due to their diverse structures and properties.
- Tetra-dentate ligands offer unique coordination environments for metal ions, influencing complex stability and reactivity.
Purpose of the Study:
- To synthesize and characterize novel blue/purple cobalt(II) chloride complexes using various tetra-dentate and tridentate ligands.
- To elucidate the structural, electronic, and magnetic properties of these newly synthesized cobalt complexes.
Main Methods:
- Synthesis of cobalt(II) chloride complexes with ligands: 1,4-bis-[2-(pyridin-2-yl)eth-yl]piperazine (Ppz), 1,4-bis-[2-(pyridin-2-yl)eth-yl]homopiperazine (Phpz), trans-2,5-dimethyl-1,4-bis-[2-(pyridin-2-yl)eth-yl]piperazine (Pdmpz), and 4-methyl-1-[2-(pyridin-2-yl)eth-yl]homopiperazine (Pmhpz).
- X-ray crystallography to determine the solid-state structures of the complexes.
- UV-Visible and Near-Infrared spectroscopy to analyze electronic transitions.
- Theoretical calculations (TDDFT) to understand electronic transitions.
- Variable-temperature magnetic susceptibility measurements to investigate magnetic properties.
Main Results:
- Dinuclear cobalt(II) complexes (Co2(Ppz)Cl4) and mononuclear complexes (Co(Phpz)Cl2, Co(Pmhpz)Cl2, [Co(Ppz)Cl]ClO4) were synthesized and structurally characterized.
- Complexes exhibited different coordination geometries, including tetrahedral and penta-coordinate trigonal-bipyramidal.
- Electronic spectra revealed distinct coordination spheres, with TDDFT calculations indicating contributions from MLCT, LMCT, and d-d transitions.
- Magnetic susceptibility data for Co(Pmhpz)Cl2 and Co(Phpz)Cl2 were modeled using zero-field-splitting, yielding D values of +28 and +39 cm-1, respectively.
Conclusions:
- The study successfully synthesized and characterized a series of novel cobalt(II) chloride complexes with diverse ligands.
- Structural and spectroscopic analyses provided insights into the coordination chemistry and electronic behavior of these complexes.
- The findings contribute to the understanding of structure-property relationships in cobalt coordination compounds.
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