Mononuclear Nonheme High-Spin (S =2) versus Intermediate-Spin (S =1) Iron(IV)-Oxo Complexes in Oxidation Reactions

2016 ◽  
Vol 55 (28) ◽  
pp. 8027-8031 ◽  
Author(s):  
Seong Hee Bae ◽  
Mi Sook Seo ◽  
Yong-Min Lee ◽  
Kyung-Bin Cho ◽  
Won-Suk Kim ◽  
...  
Keyword(s):  
High Spin ◽  
Oxidation Reactions ◽  
Oxo Complexes ◽  
Intermediate Spin

Mononuclear Nonheme High-Spin (S =2) versus Intermediate-Spin (S =1) Iron(IV)-Oxo Complexes in Oxidation Reactions

2016 ◽  
Vol 128 (28) ◽  
pp. 8159-8163 ◽  
Author(s):  
Seong Hee Bae ◽  
Mi Sook Seo ◽  
Yong-Min Lee ◽  
Kyung-Bin Cho ◽  
Won-Suk Kim ◽  
...  
Keyword(s):  
High Spin ◽  
Oxidation Reactions ◽  
Oxo Complexes ◽  
Intermediate Spin

MO-Theoretical Studies on a Model Complex for Deoxymyoglobin

1998 ◽  
Vol 53 (9) ◽  
pp. 755-765
Author(s):  
Christian Kollma ◽  
Sighart F. Fischer ◽  
Michael C. Böhm
Keyword(s):  
High Spin ◽  
Ground State ◽  
High Spin State ◽  
Open Shell ◽  
Spin States ◽  
Hartree Fock ◽  
Intermediate Spin ◽  
Model Complex ◽  
Out Of Plane ◽  
Overlap Method

AbstractThe origin of the displacement of the Fe atom in deoxymyoglobin with respect to the porphyrin plane in the high-spin state is examined by a qualitative molecular orbital (MO) analysis on the extended Hückel level. We find that attachment of a fifth ligand (imidazole in our model complex) to Fe(II)porphyrin favors the out-of-plane shift due to a strengthening of the bonding interaction between Fe and the nitrogen of the imidazole ligand. This results in a high-spin (5 = 2) ground state with Fe shifted out-of-plane for the five-coordinate complex instead of an intermediate spin ground state (5 = 1) with Fe lying in the plane for four-coordinate Fe(II)porphyrin. The relative energies of the different spin states as a function of the distance between Fe and the porphyrin plane are evaluated using an ROHF (restricted open shell Hartree-Fock) version of an INDO (intermediate neglect of differential overlap) method. We observe a level crossing between high-spin and intermediate spin states whereas the low-spin (5 = 0) state remains always higher in energy.

scholarly journals A Kinetic Study on the Efficient Formation of High-Valent Mn(TPPS)-oxo Complexes by Various Oxidants

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 610
Author(s):  
Magdalena Procner ◽  
Łukasz Orzel ◽  
Grażyna Stochel ◽  
Rudi van Eldik
Keyword(s):  
Transition Metal Complexes ◽  
Peracetic Acid ◽  
Research Work ◽  
Sodium Perborate ◽  
Oxidation Reactions ◽  
Oxo Complexes ◽  
Significant Research ◽  
Order Of Magnitude ◽  
High Valent ◽  
Harmful Effects

New, more efficient methods of wastewater treatment, which will limit the harmful effects of textile dyes on the natural environment, are still being sought. Significant research work suggests that catalysts based on transition metal complexes can be used in efficient and environmentally friendly processes. In this context, a number of compounds containing manganese have been investigated. A suitable catalyst should have the capacity to activate a selected oxidant or group of oxidants, in order to be used in industrial oxidation reactions. In the present study we investigated the ability of MnIII(TPPS), where TPPS = 5,10,15,20-tetrakis(4-sulphonatophenyl)-21H,23H-porphyrine, to activate five different oxidants, namely hydrogen peroxide, peracetic acid, sodium hypochlorite, potassium peroxomonosulfate and sodium perborate, via the formation of high valent Mn(TPPS)-oxo complexes. Kinetic and spectroscopic data showed that the oxidation process is highly pH dependent and is strongly accelerated by the presence of carbonate in the reaction mixture for three of the five oxidizing agents. The highest efficiency for the oxidation of MnIII(TPPS) to high-valent Mn(TPPS)-oxo complexes, was found for peracetic acid at pH ≈ 11 in 0.5 M carbonate solution, which is at least an order of magnitude higher than the rate constants found for the other tested oxidants under similar conditions.

scholarly journals Adsorption of iron tetraphenylporphyrin on (111) surfaces of coinage metals: a density functional theory study

2017 ◽  
Vol 8 ◽  
pp. 2484-2491 ◽  
Author(s):  
Hao Tang ◽  
Nathalie Tarrat ◽  
Véronique Langlais ◽  
Yongfeng Wang
Keyword(s):  
Density Functional Theory ◽  
High Spin ◽  
Density Functional ◽  
Activation Barrier ◽  
High Spin State ◽  
Coulomb Repulsion ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Intermediate Spin ◽  
Magnetic States

The adsorption of the iron tetraphenylporphyrin (FeTPP) molecule in its deckchair conformation was investigated on Au(111), Ag(111) and Cu(111) surfaces by performing spin-polarized density functional theory (DFT) calculations taking into account both van der Waals (vdW) interaction and on-site Coulomb repulsion. The deckchair conformation of the molecule favours intermolecular π–π-type interactions in a less densely packed monolayer than the saddle conformation. The activation barrier between the two stable magnetic states (high spin, S = 2 and intermediate spin, S = 1) of the molecule in vacuum disappears upon adsorption on the metal surfaces. The high-spin state of physisorbed FeTPP is stable on all adsorption sites. This result reveals that an external permanent element such as a STM tip or an additional molecule is needed to use FeTPP or similar molecules as model system for molecular spin switches.

ChemInform Abstract: Oxidation Reactions with Bioinspired Mononuclear Non-Heme Metal-Oxo Complexes

ChemInform ◽  
2016 ◽  
Vol 47 (35) ◽  
Author(s):  
Xenia Engelmann ◽  
Ines Monte-Perez ◽  
Kallol Ray
Keyword(s):  
Oxidation Reactions ◽  
Oxo Complexes

Influence of Ligand Architecture on Oxidation Reactions by High-Valent Nonheme Manganese Oxo Complexes Using Water as a Source of Oxygen

2014 ◽  
Vol 54 (7) ◽  
pp. 2095-2099 ◽  
Author(s):  
Prasenjit Barman ◽  
Anil Kumar Vardhaman ◽  
Bodo Martin ◽  
Svenja J. Wörner ◽  
Chivukula V. Sastri ◽  
...  
Keyword(s):  
Oxidation Reactions ◽  
Oxo Complexes ◽  
High Valent

scholarly journals Co-Substitution Effect in Room-Temperature Ferromagnetic Oxide Sr3.1Y0.9Co4O10.5

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2301
Author(s):  
Akihiro Tsuruta ◽  
Shuji Kawasaki ◽  
Masashi Mikami ◽  
Yoshiaki Kinemuchi ◽  
Yoshitake Masuda ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
High Spin ◽  
Spin State ◽  
Room Temperature ◽  
High Spin State ◽  
Substitution Effect ◽  
Co Substitution ◽  
Intermediate Spin ◽  
Intermediate Spin State

We investigated the Co substitution effect for the magnetic properties in room-temperature ferromagnetic oxide Sr3.1Y0.9Co4O10.5. The substituted element (Al and Ga) and low-spin state Co3+, which was changed from a high-spin or intermediate-spin state by Al or Ga substitution, reduced the Curie temperature to even 1.5 times lower than the temperature estimated from a simple dilution effect. Al3+ preferentially substituted for intermediate-spin-state Co3+ in the ferrimagnetic CoO6 layer and deteriorated the saturation magnetization of Sr3.1Y0.9Co4O10.5. By contrast, Ga3+ substituted for high-spin-state Co3+ in the CoO6 layer and/or the antiferromagnetic CoO4.25 layer and enhanced the saturation magnetization per Co ion. These results indicate that the magnetic properties of Sr3.1Y0.9Co4O10.5 can be controlled by selectively substituting for Co3+ with different spin states.

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