scholarly journals Influencing the coordination mode of tbta (tbta = tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine) in dicobalt complexes through changes in metal oxidation states

2013 ◽  
Vol 42 (19) ◽  
pp. 6944 ◽  
Author(s):  
David Schweinfurth ◽  
Johannes Klein ◽  
Stephan Hohloch ◽  
Sebastian Dechert ◽  
Serhiy Demeshko ◽  
...  
Keyword(s):  
Coordination Mode ◽  
Oxidation States ◽  
Metal Oxidation ◽  
Methyl Amine

Inherent Selectivity of Pd C–H Activation from Different Metal Oxidation States

2021 ◽  
Author(s):  
Peter Amadeo ◽  
Bangaru Bhaskararao ◽  
Yun-Fang Yang ◽  
Marisa C. Kozlowski
Keyword(s):  
Oxidation States ◽  
Metal Oxidation

Monodisperse Samarium and Cerium Orthovanadate Nanocrystals and Metal Oxidation States on the Nanocrystal Surface

Langmuir ◽  
2009 ◽  
Vol 25 (18) ◽  
pp. 11142-11148 ◽  
Author(s):  
Thanh-Dinh Nguyen ◽  
Cao-Thang Dinh ◽  
Trong-On Do
Keyword(s):  
Oxidation States ◽  
Metal Oxidation

scholarly journals Metrical Oxidation States of 1,4-Diazadiene (DAD) Derived Ligands

2020 ◽  
Author(s):  
F.J. de Zwart ◽  
Bente Reus ◽  
Annechien A.H. Laporte ◽  
Vivek Sinha ◽  
Bas de Bruin
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Oxidation State ◽  
Transition Metal Complexes ◽  
Coordination Mode ◽  
Chemical Reactivity ◽  
Accurate Determination ◽  
Oxidation States ◽  
Wide Range ◽  
Ligand Bond

The conventional method of assigning formal oxidation states (FOS) to metals and ligands is an important tool for understanding and predicting chemical reactivity, in particular in catalysis research. For complexes containing redox-noninnocent ligands, the oxidation state of the ligand can be ambiguous (i.e. their spectroscopic oxidation state can differ from the formal oxidation state), and thus frustrates the assignment of the oxidation state of the metal. A quantitative correlation between empirical metric data of redox active ligands and their oxidation states using a metrical oxidation state (MOS) model has been developed for catecholate and aminophenolate derived ligands by Brown. In the present work, we present a MOS model for 1,4-diazabutadiene (DAD<sup>n</sup>) ligands. The model is based on a similar approach as reported by Brown, correlating the intra-ligand bond lengths of the DAD<sup>n</sup> moiety in a quantitative manner to the MOS using geometrical information from X-ray structures in the Cambridge Crystallographic Data Center (CCDC) database. However, accurate determination of the MOS of these ligands turned-out to be dependent the coordination mode of the DAD<sup>2-</sup> moiety, which can adopt both a planar <i>κ<sup>2</sup></i>-<i>N<sub>2</sub></i>-geometry and a <i>η<sup>4</sup></i>-<i>N<sub>2</sub></i>-<i>C<sub>2</sub></i> π-coordination mode in (transition) metal complexes in its doubly reduced, dianionic enediamide oxidation state. A reliable MOS model was developed taking the intrinsic differences in intra-ligand bond distances between these coordination modes of the DAD<sup>2‒</sup> ligand into account. Three different models were defined and tested using different geometric parameters (C=C→M distance, M-N-C angle, M-N-C-C torsion angle) to describe the C=C backbone coordination to the metal in the <i>η<sup>4</sup></i>-<i>N<sub>2</sub></i>-<i>C<sub>2</sub></i> π-coordination mode of the DAD<sup>2‒</sup> ligand. Statistical analysis revealed that the C=C→M distance best describes the <i>η<sup>4</sup></i>-<i>N<sub>2</sub></i>-<i>C<sub>2</sub></i> coordination mode, using a cut-off value of 2.46 Å for π-coordination. The developed MOS model was used to validate the oxidation state assignment of elements not contained within the training set (Sr, Yb and Ho), thus demonstrating the applicability of the MOS model to a wide range of complexes. Chromium complexes with complex electronic structures were also shown to be accurately described by MOS analysis. Furthermore, it is shown that a combination of MOS analysis and FOD calculations provide an inexpensive method to gain insight into the electronic structure of singlet spin state (S = 0) [M(trop<sub>2</sub>dad)] transition metal complexes showing multireference character.<br>

The assignment and validation of metal oxidation states in the Cambridge Structural Database

2000 ◽  
Vol 56 (3) ◽  
pp. 455-465 ◽  
Author(s):  
Gregory P. Shields ◽  
Paul R. Raithby ◽  
Frank H. Allen ◽  
W. D. Samuel Motherwell
Keyword(s):  
Bond Length ◽  
Copper Complexes ◽  
Search Time ◽  
Cambridge Structural Database ◽  
Oxidation States ◽  
Metal Oxidation ◽  
Metal Atoms ◽  
Organic Complexes ◽  
Length Data ◽  
Structural Database

A methodology has been developed for the semi-automatic assignment and checking of formal oxidation states for metal atoms in the majority of metallo-organic complexes stored in the Cambridge Structural Database (CSD). The method uses both chemical connectivity and bond-length data, via ligand donor group templates and bond-valence sums, respectively. In order to use bond-length data, the CSD program QUEST has been modified to allow the coordination sphere of metal atoms to be recalculated using user-defined criteria at search time. The new methodology has been used successfully to validate the +1, +2 and +3 oxidation states in 743 four-coordinate copper complexes in the CSD for which atomic coordinates are available in ca 99% of structures using one or other method, and both succeed for >86% of structures.

scholarly journals Single crystal structures and theoretical calculations of uranium endohedral metallofullerenes (U@C2n, 2n = 74, 82) show cage isomer dependent oxidation states for U

2017 ◽  
Vol 8 (8) ◽  
pp. 5282-5290 ◽  
Author(s):  
Wenting Cai ◽  
Roser Morales-Martínez ◽  
Xingxing Zhang ◽  
Daniel Najera ◽  
Elkin L. Romero ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Oxidation State ◽  
Theoretical Calculations ◽  
State Dependence ◽  
Oxidation States ◽  
Metal Oxidation ◽  
X Ray ◽  
Endohedral Metallofullerenes ◽  
Single Crystal Structures

First X-ray structures and metal oxidation state dependence on cage isomerism for U-EMFs.

scholarly journals Non-equilibrium oxidation states of zirconium during early stages of metal oxidation

2015 ◽  
Vol 106 (10) ◽  
pp. 101603 ◽  
Author(s):  
Wen Ma ◽  
F. William Herbert ◽  
Sanjaya D. Senanayake ◽  
Bilge Yildiz
Keyword(s):  
Oxidation States ◽  
Metal Oxidation ◽  
Early Stages ◽  
Non Equilibrium

scholarly journals Metrical Oxidation States of 1,4-Diazadiene (DAD) Derived Ligands

2020 ◽  
Author(s):  
F.J. de Zwart ◽  
Bente Reus ◽  
Annechien A.H. Laporte ◽  
Vivek Sinha ◽  
Bas de Bruin
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Oxidation State ◽  
Transition Metal Complexes ◽  
Coordination Mode ◽  
Chemical Reactivity ◽  
Accurate Determination ◽  
Oxidation States ◽  
Wide Range ◽  
Ligand Bond

The conventional method of assigning formal oxidation states (FOS) to metals and ligands is an important tool for understanding and predicting chemical reactivity, in particular in catalysis research. For complexes containing redox-noninnocent ligands, the oxidation state of the ligand can be ambiguous (i.e. their spectroscopic oxidation state can differ from the formal oxidation state), and thus frustrates the assignment of the oxidation state of the metal. A quantitative correlation between empirical metric data of redox active ligands and their oxidation states using a metrical oxidation state (MOS) model has been developed for catecholate and aminophenolate derived ligands by Brown. In the present work, we present a MOS model for 1,4-diazabutadiene (DAD<sup>n</sup>) ligands. The model is based on a similar approach as reported by Brown, correlating the intra-ligand bond lengths of the DAD<sup>n</sup> moiety in a quantitative manner to the MOS using geometrical information from X-ray structures in the Cambridge Crystallographic Data Center (CCDC) database. However, accurate determination of the MOS of these ligands turned-out to be dependent the coordination mode of the DAD<sup>2-</sup> moiety, which can adopt both a planar <i>κ<sup>2</sup></i>-<i>N<sub>2</sub></i>-geometry and a <i>η<sup>4</sup></i>-<i>N<sub>2</sub></i>-<i>C<sub>2</sub></i> π-coordination mode in (transition) metal complexes in its doubly reduced, dianionic enediamide oxidation state. A reliable MOS model was developed taking the intrinsic differences in intra-ligand bond distances between these coordination modes of the DAD<sup>2‒</sup> ligand into account. Three different models were defined and tested using different geometric parameters (C=C→M distance, M-N-C angle, M-N-C-C torsion angle) to describe the C=C backbone coordination to the metal in the <i>η<sup>4</sup></i>-<i>N<sub>2</sub></i>-<i>C<sub>2</sub></i> π-coordination mode of the DAD<sup>2‒</sup> ligand. Statistical analysis revealed that the C=C→M distance best describes the <i>η<sup>4</sup></i>-<i>N<sub>2</sub></i>-<i>C<sub>2</sub></i> coordination mode, using a cut-off value of 2.46 Å for π-coordination. The developed MOS model was used to validate the oxidation state assignment of elements not contained within the training set (Sr, Yb and Ho), thus demonstrating the applicability of the MOS model to a wide range of complexes. Chromium complexes with complex electronic structures were also shown to be accurately described by MOS analysis. Furthermore, it is shown that a combination of MOS analysis and FOD calculations provide an inexpensive method to gain insight into the electronic structure of singlet spin state (S = 0) [M(trop<sub>2</sub>dad)] transition metal complexes showing multireference character.<br>

How Innocent are Potentially Redox Non-Innocent Ligands? Electronic Structure and Metal Oxidation States in Iron-PNN Complexes as a Representative Case Study

2015 ◽  
Vol 54 (10) ◽  
pp. 4909-4926 ◽  
Author(s):  
Burkhard Butschke ◽  
Kathlyn L. Fillman ◽  
Tatyana Bendikov ◽  
Linda J. W. Shimon ◽  
Yael Diskin-Posner ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Oxidation States ◽  
Metal Oxidation ◽  
Representative Case

scholarly journals Metal oxidation states in biological water splitting

2015 ◽  
Vol 6 (3) ◽  
pp. 1676-1695 ◽  
Author(s):  
Vera Krewald ◽  
Marius Retegan ◽  
Nicholas Cox ◽  
Johannes Messinger ◽  
Wolfgang Lubitz ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Water Splitting ◽  
Oxidation States ◽  
Oxygen Evolving Complex ◽  
Central Question ◽  
Manganese Ions ◽  
Metal Oxidation ◽  
Biological Water ◽  
Oxygen Evolving

A central question in biological water splitting concerns the oxidation states of the manganese ions that comprise the oxygen-evolving complex of photosystem II.

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