Thermodynamic data for the binding of molecular oxygen to cobalt(II) protoporphyrin IX dimethyl ester

Beugelsdijk, Tony J.; Drago, Russell S.

doi:10.1021/ja00855a028

Cited by 53 publications

(21 citation statements)

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Section: Oxygen Affinity In Solutionmentioning

confidence: 99%

“…The oxygenation-deoxygenation process is fully reversible and can be repeated several times in acetonitrile, acetone, ethanol and methanol solutions. Following the method described by Drago and co-workers, 25,26 the equilibrium constant for the uptake of O 2 was extracted from a plot of the partial pressure p(O 2 ) against p(O 2 )/(A − A 0 ), where A is the absorbance at the given partial pressure of O 2 and A 0 is the absorbance for p(O 2 ) = 0. A linear least-squares fit through the data points crosses the secondary axis at −1/K, where K is the equilibrium constant of eqn (3…”

Section: Oxygen Affinity In Solutionmentioning

confidence: 99%

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Tuning affinity and reversibility for O₂binding in dinuclear Co(ii) complexes

et al. 2013

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The O2 binding affinity of a series of dicobalt(II) complexes can be tuned between p(O2)50% = 2.3 × 10(-3) and 700 × 10(-3) atm at 40 °C by varying the number of H and Cl atoms in the bridging acetato ligands of [Co2(bpbp)(CH(3-n)ClnCO2)(CH3CN)2](2+), where bpbp(-) = 2,6-bis(N,N-bis(2-pyridylmethyl)aminomethyl)-4-tert-butylphenolate and n = {0, 1, 2, 3}. O2 binds most strongly to the deoxy complex containing the acetato bridge and the O2 affinity decreases linearly as the number of Cl atoms is increased from 0 to 3 in [Co2(bpbp)(O2)(CH3CO2)](2+), [Co2(bpbp)(O2)(CH2ClCO2)](2+), [Co2(bpbp)(O2)(CHCl2CO2)](2+) and [Co2(bpbp)(O2)(CCl3CO2)](2+). The O2 affinities can be qualitatively correlated with both the pKa value of the parent acetic or chloroacetic acid and the redox potential of the O2(2-)/O2˙(-) couple measured for the peroxide-bridged complexes. The redox potential varies between 510 mV (vs. Fc(0/+)) for the acetato-bridged complex to 696 mV for the trichloroacetato-bridged system. Despite the clear difference in reactivity in solution, there are no clear trends which can be correlated to O2 affinity in the O-O bond lengths in the X-ray crystal structures at 180 K (1.415(4)-1.424(2) Å) or in the frequencies of the peroxido O-O stretch in the solid-state resonance Raman spectra at 298 K (830-836 cm(-1)). Using density functional theory calculations, we conclude that the Co(II) atoms of the deoxy complexes coordinate solvent molecules as auxiliary ligands and that a conformation change of the ligand is involved in the reversible O2 binding process. The alternative of five coordination in the deoxy Co(II) complexes is therefore seen as less likely. The crystal structure and p(O2)50% are also reported for the 1-naphthoato-bridged oxy complex [Co2(bpbp)(O2)(C10H7O2)](2+), and the O2 binding affinity in that case is also qualitatively consistent with the expectation from the pKa of the parent 1-naphthoic acid.

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Section: Oxygen Affinity In Solutionmentioning

confidence: 99%

Section: Oxygen Affinity In Solutionmentioning

confidence: 99%

Tuning affinity and reversibility for O₂binding in dinuclear Co(ii) complexes

et al. 2013

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“…We prepared another toluene solution of ( E )‐ 1 ‐CoS, where the amount of the naphthalenyl vinylpyridie residues was 10‐fold in excessive to that of CoS (in mol). The oxygen‐binding equilibrium constant ( K ) in eqn (1) was determined by Drago's method with the change in absorbance at 565 nm depending upon the partial pressure of oxygen supplied: 1.7 × 10 −2 mmHg −1 for ( E )‐ 1 ‐CoS in toluene at 14°C 22–25. The K value of ( E )‐ 2 ‐CoS was 3.3 × 10 −2 mmHg −1 at 10°C as reported 20.…”

Section: Resultsmentioning

confidence: 99%

Photo‐reversible oxygen binding of a cobalt schiff‐base complex with an axially coordinating photo‐isomerizable polymer ligand

Suzuki

Hachisu

et al. 2011

Polymers for Advanced Techs

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The reversible binding of oxygen to N,N(-ethylene bis(salicylideneiminato) cobalt(II) (CoS), to which a photoisomerizable naphthalenyl vinylpyridine residue of copolymer 1 coordinated, was investigated. The E form of the naphthalenyl vinylpyridine residues coordinating to CoS, (E)-1-CoS, showed photo-reversible isomerization into the Z form, (Z)-1-CoS, on direct ultraviolet (UV) irradiation in a range of 335-345 nm and vice versa on another UV irradiation in a range of 285-295 nm. Reversible change of oxygen-binding affinity of 1-CoS corresponding to the photo-reversible E/Z isomerization of the naphthalenyl vinylpyridine residues was also observed in absorption spectra. Steric hindrance of the polymer chain of 1 on the coordination of the naphthalenyl vinylpyridine residue of (Z)-1 to CoS was thought to cause the decrease of oxygen-binding affinity of (Z)-1-CoS.

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“…15 The thermodynamics parameter such as ∆H o and ∆S o were calculated using Van't Hoff equation. 16,17…”

Section: Oxygen Binding Studymentioning

confidence: 99%

Synthesis, spectroscopic characterization, DFT, oxygen binding, antioxidant activity on Fe(III), Co(II) and Ni(II) complexes with a tetradentate ONNO donor Schiff base ligand

Shukla

Gaur

Raidas

et al. 2021

JSCS

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The Schiff base ligand, namely (7E)-N-benzylidene-2-styrylbenzena-mine1,2-diamine-2,4-dihydroxy-phenol, (L), was synthesized from condensation of 2,4-dihydroxybenzaldehyde with o-phenylenediamine. The reaction of the ligand with Fe(III), Co(II) and Ni(II) salts in a 1: 1 ratio yielded three complexes 1-3. Different analytical tools like elemental analysis, ESI-mass spectra, FT-IR, conductivity, electronic spectra, magnetic susceptibility, NMR and EPR mea-surements are used to elucidate the structure of the ligand and complexes. Density Functional Theory (DFT) calculation at the B3LYP/3-211G++/LANL2DZ level of the theory has been carried out to optimize the geometry of the ligand and complexes. The tetradentate ligand has coordinated to metals through ONNO donors affording octahedral geometry. Complexes were studied for their oxygen-binding activity and free radical scavenging activities. Complex 1 and 2, which contain Fe(IIl) and Co(II), displayed reversible oxygen binding activity. On the other hand, complex 3 fails to show oxygen binding. The order of antioxidant activity is 3 > 1 > 2 > L.

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Thermodynamic data for the binding of molecular oxygen to cobalt(II) protoporphyrin IX dimethyl ester

Cited by 53 publications

References 5 publications

Tuning affinity and reversibility for O₂binding in dinuclear Co(ii) complexes

Tuning affinity and reversibility for O₂binding in dinuclear Co(ii) complexes

Photo‐reversible oxygen binding of a cobalt schiff‐base complex with an axially coordinating photo‐isomerizable polymer ligand

Synthesis, spectroscopic characterization, DFT, oxygen binding, antioxidant activity on Fe(III), Co(II) and Ni(II) complexes with a tetradentate ONNO donor Schiff base ligand

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Thermodynamic data for the binding of molecular oxygen to cobalt(II) protoporphyrin IX dimethyl ester

Cited by 53 publications

References 5 publications

Tuning affinity and reversibility for O2binding in dinuclear Co(ii) complexes

Tuning affinity and reversibility for O2binding in dinuclear Co(ii) complexes

Photo‐reversible oxygen binding of a cobalt schiff‐base complex with an axially coordinating photo‐isomerizable polymer ligand

Synthesis, spectroscopic characterization, DFT, oxygen binding, antioxidant activity on Fe(III), Co(II) and Ni(II) complexes with a tetradentate ONNO donor Schiff base ligand

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Tuning affinity and reversibility for O₂binding in dinuclear Co(ii) complexes

Tuning affinity and reversibility for O₂binding in dinuclear Co(ii) complexes