Synthesis, magnetic properties, and phosphoesterase activity of dinuclear cobalt(II) complexes

Daumann, Lena J., Comba, Peter, Larrabee, James A., Schenk, Gerhard, Stranger, Robert, Cavigiasso, German and Gahan, Lawrence R. (2013) Synthesis, magnetic properties, and phosphoesterase activity of dinuclear cobalt(II) complexes. Inorganic Chemistry, 52 4: 2029-2043. doi:10.1021/ic302418x

Author Daumann, Lena J.
Comba, Peter
Larrabee, James A.
Schenk, Gerhard
Stranger, Robert
Cavigiasso, German
Gahan, Lawrence R.
Title Synthesis, magnetic properties, and phosphoesterase activity of dinuclear cobalt(II) complexes
Journal name Inorganic Chemistry   Check publisher's open access policy
ISSN 0020-1669
Publication date 2013-02
Sub-type Article (original research)
DOI 10.1021/ic302418x
Volume 52
Issue 4
Start page 2029
End page 2043
Total pages 15
Place of publication Washington, DC, United States
Publisher American Chemical Society
Collection year 2014
Language eng
Formatted abstract
A series of dinuclear cobalt(II) complexes has been prepared and characterized to generate functional and spectroscopic models for cobalt(II) substituted phosphoesterase enzymes such as the potential bioremediator GpdQ. Reaction of ligands based on 2,2'-(((2-hydroxy-5-methyl-1,3-phenylene) bis(methylene))bis((pyridin-2-ylmethyl)azanediyl)))diethanol (L1) and 2,6-bis(((2-methoxyethyl)(pyridin-2-ylmethyl)amino)methyl)-4-methylphenol (L2) with cobalt(II) salts afforded [Co2(CO2EtH 2L1)(CH3COO)2](PF6), [Co 2(CO2EtL2)(CH3COO)2](PF 6), [Co2(CH3L2)(CH3COO) 2](PF6), [Co2(BrL2)(CH3COO) 2](PF6), and [Co2(NO2L2)(CH 3COO)2](PF6). Complexes of the L2 ligands contain a coordinated methyl-ether, whereas the L1 ligand contains a coordinated alcohol. The complexes were characterized using mass spectrometry, microanalysis, X-ray crystallography, UV-vis-NIR diffuse reflectance spectroscopy, IR absorption spectroscopy, solid state magnetic susceptibility measurements, and variable-temperature variable-field magnetic circular dichroism (VTVH MCD) spectroscopy. Susceptibility studies show that [Co 2(CO2EtH2L1)(CH3COO) 2](PF6), [Co2(CO2EtL2)(CH 3COO)2](PF6), and [Co2(CH 3L2)(CH3COO)2](PF6) are weakly antiferromagnetically coupled, whereas [Co2(BrL2)(CH 3COO)2](PF6) and [Co2(NO 2L2)(CH3COO)2](PF6) are weakly ferromagnetically coupled. The susceptibility results are confirmed by the VTVH MCD studies. Density functional theory calculations revealed that magnetic exchange coupling occurs mainly through the phenolic oxygen bridge. Implications of geometry and ligand design on the magnetic exchange coupling will be discussed. Functional studies of the complexes with the substrate bis(2,4-dinitrophenyl) phosphate showed them to be active towards hydrolysis of phosphoester substrates.
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Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
School of Chemistry and Molecular Biosciences
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