Mössbauer effect study of Cs2Fe(57Co)O4

Kopelev, N. S.; Куликов, Л. А.; Perfil’ev, Yu. D.

doi:10.1007/bf02069142

Cited by 6 publications

(3 citation statements)

References 16 publications

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“…In particular, such compounds as CoO 2 dioxide and cesium hexafluorocobaltate(IV) Cs 2 CoF 6 [4,5], have been known for Co(IV) for a long time and for Co(V), sodium tetraoxocobaltates(V) Na 3 CoO 4 and potassium K 3 CoO 4 [6,7], and also a number of organometallic complexes [3,[8][9][10]. An availability of Co(VI) was supposed in the matrix of cesium tetraoxoferrate(VI) (Cs 2 FeO 4 ) as isomorphically replacing Fe(VI), and its identification was carried out by Mössbauer spectroscopy [11]; however, any compound with a stoichiometric chemical composition for a given oxidation state of cobalt was described neither in this work nor in other publications. By taking into account the theoretical considerations expressed in the introduction to the articles [12,13] devoted to Cu(IV) and Zn(IV) complexes with porphyrazine and its benzo-derivatives (in particular, trans-di[benzo]porphyrazine and tetra[benzo]porphyrazine) and one oxo ligand, we have every reason to believe that the given macrocyclic ligands in combination with two oxo ligands will also be able to form complexes with structural formulas [CoL1(O) 2 ] (I), [CoL2(O) 2 ] (II) and [CoL3(O) 2 ] (III) (where L1 2− , L2 2− and L3 2− are double deprotonated forms of porphyrazine H 2 L1, trans-di[benzo]porphyrazine H 2 L2 and tetra[benzo]porphyrazine H 2 L3).…”

Section: Introductionmentioning

confidence: 99%

DFT Quantum-Chemical Modeling Molecular Structures of Cobalt Macrocyclic Complexes with Porphyrazine or Its Benzo-Derivatives and Two Oxygen Acido Ligands

Михайлов

Чачков

2020

IJMS

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Based on the results of a quantum chemical calculation using the DFT method with the OPBE/TZVP and B3PW91/TZVP levels, the possibility of the existence of three cobalt heteroligand complexes containing in the inner coordination sphere porphyrazine, di[benzo]- and tetra[benzo]porphyrazine, and two oxygen (O2−) ions with probable oxidation state VI of Co, which is unknown for this element at the present time, was shown. Data on the structural parameters are presented. It was shown that CoN4 chelate nodes as well as all metal-chelate and non-chelate cycles in each of these complexes, were strictly planar. Besides, the bond angles formed by two donor nitrogen atoms and a Co atom were close or equal to 90°, while the bond angles formed by donor atoms N, Co, and O, in most cases, albeit insignificantly, differed from this value. Good agreement between the calculated data obtained using the above two versions of the DFT method was found. Standard thermodynamic parameters of formation (standard enthalpy ΔH0f, 298, entropy S0f, 298 and Gibbs’s energy ΔG0f, 298) for the indicated complexes were presented too.

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Section: Introductionmentioning

confidence: 99%

DFT Quantum-Chemical Modeling Molecular Structures of Cobalt Macrocyclic Complexes with Porphyrazine or Its Benzo-Derivatives and Two Oxygen Acido Ligands

Михайлов

Чачков

2020

IJMS

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“…For cobalt, +6 is the highest OS. 33,34 This state was identified by emission MoÈ ssbauer spectroscopy. The detection of OS by this method may indicate that it is highly unstable.…”

Section: Regularities Of Changes In the Extreme Oxidation Statesmentioning

confidence: 99%

“…Refs 31 and 32) and the detection of Co VI in a cesium ferrate matrix. 33,34 Studies of the properties of elements with atomic numbers 104, 105 and 106, viz., rutherfordium, dubnium and seaborgium, 35,36 and the possibility of generation of Hg IV (see Refs 37 and 38) are also worthy of note.…”

Section: Introductionmentioning

confidence: 99%

The problem of oxidation state stabilisation and some regularities of a Periodic system of the elements

Kiselev¹,

Tretiyakov²

1999

Russ. Chem. Rev.

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The general principles of the concept of oxidation state stabilisation are formulated. Problems associated with the preparation and provision of the highest valent forms of transition elements are considered. The empirical data concerning the synthesis of new compounds of rare-earth elements and d elements in unusually high oxidation states are analysed. The possibility of occurrence of the oxidation states + 9 and + 10 for some elements (for example, for iridium and platinum in tetraoxo ions) are discussed. Approaches to the realisation of these states are outlined and it is demonstrated that solid phases or matrices containing alkali metal cations are the most promising systems for the stabilisation of these high oxidation states. Selected thermodynamic features typical of metal halides and oxides and the regularities of the changes in the extreme oxidation states of d elements are considered. The bibliography includes 266 references.

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On matrix stabilisation of d- and f-transition metal ions in unstable oxidation states

Kiselev¹

2009

Russ. Chem. Rev.

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Mössbauer effect study of Cs2Fe(57Co)O4

Cited by 6 publications

References 16 publications

DFT Quantum-Chemical Modeling Molecular Structures of Cobalt Macrocyclic Complexes with Porphyrazine or Its Benzo-Derivatives and Two Oxygen Acido Ligands

DFT Quantum-Chemical Modeling Molecular Structures of Cobalt Macrocyclic Complexes with Porphyrazine or Its Benzo-Derivatives and Two Oxygen Acido Ligands

The problem of oxidation state stabilisation and some regularities of a Periodic system of the elements

On matrix stabilisation of d- and f-transition metal ions in unstable oxidation states

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