Fluorination of Some Group IX and X Metals and Their Lower Fluorides by Monofluorine and Difluorine Mixtures

The properties and reactivities of transition metal complexes are often discussed in terms of Ligand Field Theory (LFT), and with ab initio LFT a direct connection to quantum chemical wavefunctions was recently established. The Angular Overlap Model (AOM) is a widely used, ligandspecific parameterization scheme of the ligand field splitting that has, however, been restricted by the availability and resolution of experimental data. Using ab initio LFT, we present here a generalised, symmetry-independent and automated fitting procedure for AOM parameters that is even applicable to formally underdetermined or experimentally inaccessible systems. This method allows quantitative evalua-tions of assumptions commonly made in AOM applications, for example, transferability or the relative magnitudes of AOM parameters, and the response of the ligand field to structural or electronic changes. A two-dimensional spectrochemical series of tetrahedral halido metalates ([M II X 4 ] 2À , M = MnÀ Cu) served as a case study. A previously unknown linear relationship between the halide ligands' chemical hardness and their AOM parameters was found. The impartial and automated procedure for identifying AOM parameters introduced here can be used to systematically improve our understanding of ligand-metal interactions in coordination complexes.

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“… [85] Publications on the synthesis and characterization of gaseous CoF 3 , CoF 4 ,

and respective cations are known. [ 86 , 87 ]…”

Section: Resultsmentioning

confidence: 99%

Revisiting the Fundamental Nature of Metal‐Ligand Bonding: An Impartial and Automated Fitting Procedure for Angular Overlap Model Parameters

Buchhorn

Deeth

Krewald

2022

Chemistry A European J

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“…Solid NiF 4 is one of the strongest known fluorinating oxidizing agents, [2] but it is poorly characterized spectroscopically and even its solid‐state structure is unknown. We have not found any report on molecular or gaseous NiF 4 [4] . Fluorination of solid NiF 2 provides thermally unstable higher nickel fluorides such as Ni 2 F 5 (Ni II 3 Ni IV F 10 ) [14] or R‐NiF 3 (Ni II Ni VI F 6 ), [15] and neutral NiF 4 is claimed to be formed at about −60 °C by treating [NiF 6 ] 2− salts in anhydrous HF with strong Lewis acids such as AsF 5 , SbF 5 , or BF 3 [16] .…”

Section: Figurementioning

confidence: 91%

“…CoF 3 is of industrial importance in the Flutec or Fowler processes, [2] and higher nickel fluorides are considered to be the active fluorinating agents in the electrochemical fluorination of organic substrates (Simons process) [3] . Despite numerous attempts to elucidate this latter process the active species are still unknown [3, 4] …”

Section: Figurementioning

confidence: 99%

Searching for Monomeric Nickel Tetrafluoride: Unravelling Infrared Matrix Isolation Spectra of Higher Nickel Fluorides

Sakr

Schlöder

et al. 2021

Angew Chem Int Ed

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Binary transition metal fluorides are textbook examples combining complex electronic features with most fundamental molecular structures. High‐valent nickel fluorides are among the strongest known fluorinating and oxidizing agents, but there is a lack of experimental structural and spectroscopic investigations on molecular NiF3 or NiF4. Apart from their demanding synthesis, also their quantum‐chemical description is difficult due to their open shell nature and low‐lying excited electronic states. Distorted tetrahedral NiF4 (D2d) and trigonal planar NiF3 (D3h) molecules were produced by thermal evaporation and laser ablation of nickel atoms in a fluorine/noble gas mixture and spectroscopically identified by a joint matrix‐isolation and quantum‐chemical study. Their vibrational band positions provide detailed insights into their molecular structures.

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“…[3] Despite numerous attempts to elucidate this latter process the active species are still unknown. [3,4] Clearly, these particular properties are related to the peculiar electronic structure of these late TM fluorides, such as high ionization energies, the occupation of M À F antibonding molecular orbitals, and the lack of the so-called "primogenic repulsion", caused by the absence of radial nodes in the 3d valence orbitals. [5] Nickel is one of the most electronegative metallic elements.…”

mentioning

confidence: 99%

“…We have not found any report on molecular or gaseous NiF 4 . [4] Fluorination of solid NiF 2 provides thermally unstable higher nickel fluorides such as Ni 2 F 5 (Ni II 3 Ni IV F 10 ) [14] or R-NiF 3 (Ni II Ni VI F 6 ), [15] and neutral NiF 4 is claimed to be formed at about À60 8C by treating [NiF 6 ] 2À salts in anhydrous HF with strong Lewis acids such as AsF 5 , SbF 5 , or BF 3 . [16] NiF 4 releases F 2 above À55 8C and forms NiF 3 , which again releases fluorine above 20 8C to form NiF 2 .…”

mentioning

confidence: 99%

Searching for Monomeric Nickel Tetrafluoride: Unravelling Infrared Matrix Isolation Spectra of Higher Nickel Fluorides

Sakr

Schlöder

et al. 2021

Angewandte Chemie

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Fluorination of Some Group IX and X Metals and Their Lower Fluorides by Monofluorine and Difluorine Mixtures

Cited by 4 publications

References 15 publications

Revisiting the Fundamental Nature of Metal‐Ligand Bonding: An Impartial and Automated Fitting Procedure for Angular Overlap Model Parameters

Revisiting the Fundamental Nature of Metal‐Ligand Bonding: An Impartial and Automated Fitting Procedure for Angular Overlap Model Parameters

Searching for Monomeric Nickel Tetrafluoride: Unravelling Infrared Matrix Isolation Spectra of Higher Nickel Fluorides

Searching for Monomeric Nickel Tetrafluoride: Unravelling Infrared Matrix Isolation Spectra of Higher Nickel Fluorides

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