scholarly journals Direct metal-carbon bonding in symmetric bis(C-H) agostic Nickel(I) complexes

2021 ◽  
Author(s):  
Weiying He ◽  
D Dawson Beattie ◽  
Hao Zhou ◽  
Eric G Bowes ◽  
Laurel L. Schafer ◽  
...  
Keyword(s):  
Transition Metal ◽  
D Orbitals ◽  
Carbon Bonding

Agostic interactions are examples of σ-type interactions, typically resulting from interactions between C-H σ-bonds with empty transition metal d orbitals. Such interactions often reflect the first step in transition metal-catalysed...

The prediction of metal-to-metal bonding in transition metal binary and related compounds

1964 ◽  
Vol 17 (11) ◽  
pp. 1191 ◽  
Author(s):  
JC Sheldon
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Valence State ◽  
Oxidation States ◽  
Metal Bonding ◽  
Binary Oxides ◽  
Lower Oxidation ◽  
D Orbitals ◽  
Related Compounds

The evidence for, and the factors determining, the formation of metal-to-metal (m-m) bonds in transition metal oxides, sulphides, halides, and related complexes are discussed. It is proposed that when metals of high preferred valence state are constrained to low formal oxidation states, m-m bonds will form to allow the metal to exercise a higher valency. It is assumed that (n-l)d orbitals are used for such bonds and predictions of the feasibility of m-m bonding are possible by the comparison of the size of such orbitals with the expected inter-metal distances in polymeric metal oxides and halides. It is concluded that binary oxides and halides (excepting fluorides) of the lower oxidation states of Zr, Hf, Nb, Ta, Mo, W, and Re and of a few neighbouring elements will display m-m bonds.

Die elektronische Struktur ternärer Übergangsmetallpnictide. I. AlB2-Varianten / The Electronic Structure of Ternary Transition Metal Pnictides. I. AlB2-Variants

1996 ◽  
Vol 51 (5) ◽  
pp. 655-664 ◽  
Author(s):  
Dirk Johrendt ◽  
Albrecht Mewis
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Local Symmetry ◽  
Orbital Interaction ◽  
Stability Criteria ◽  
Resistivity Measurements ◽  
Starting Point ◽  
Structural Peculiarities ◽  
Interaction Scheme ◽  
D Orbitals

The electronic structure and bonding of some ternary AlB2-type compounds AMX (A=2a-, X=5b-element, M=transition metal) were studied by means of Extended-Hückel and TBLMTO- ASA calculations. Previous geometric stability criteria of the AIB2 structure have been extended, and reasons for some structural peculiarities and distortions are given. A simple orbital interaction scheme based on local symmetry is used as starting point to investigate the electronic properties of these compounds, whereas the band structures of the ZrBeSi-type SrPdAs and the Peierls-distorted variants CaPdAs and BaPdP are described in more detail. The results of calculations and resistivity measurements are discussed within the scope of Zintl’s concept under consideration of the transition metal d-orbitals. It turns out that these solids can be described as metallic Zintl compounds.

scholarly journals Revealing the Role of d Orbitals of Transition-Metal-Doped Titanium Oxide on High-Efficient Oxygen Reduction

CCS Chemistry ◽  
2020 ◽  
pp. 1-22
Author(s):  
Fei Lu ◽  
Weiwei Xie ◽  
Ding Yi ◽  
Yan Wang ◽  
Fengchu Zhang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Oxygen Reduction ◽  
Titanium Oxide ◽  
High Efficient ◽  
Metal Doped ◽  
D Orbitals

Charge transport mediated by d-orbitals in transition metal complexes

2008 ◽  
pp. 247-249 ◽  
Author(s):  
Youngu Lee ◽  
Shengwen Yuan ◽  
Arturo Sanchez ◽  
Luping Yu
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Charge Transport ◽  
Transition Metal Complexes ◽  
D Orbitals

scholarly journals Nanostructured transition metal oxides obtained by SPVD

2020 ◽  
Vol 7 ◽  
pp. 12
Author(s):  
Adriana Gabriela Plăiașu ◽  
Marian Cătălin Ducu ◽  
Sorin Georgian Moga ◽  
Aurelian Denis Negrea ◽  
Ecaterina Magdalena Modan
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Physical Vapor Deposition ◽  
Manganese Oxides ◽  
Oxidation States ◽  
Microstructural Characteristics ◽  
Original Process ◽  
Synthesis Parameters ◽  
D Orbitals

The interest in the unique properties associated with materials having structures on a nanometer scale has been increasing at an exponential rate in last decade. Transition metal oxides are preferred materials for catalytic applications due to their half-filled d orbitals that make them exist in different oxidation states. Transition metal oxides show a broad structural variety due to their ability to form phases of varying metal to oxygen ratios reflecting multiple stable oxidation states of the metal ions. The Solar Physical Vapor Deposition (SPVD) presented in the paper as elaboration method is an original process to prepare nanopowders working under concentrated sunlight in 2 kW solar furnaces. The influence of the synthesis parameters on the chemical and microstructural characteristics of zinc and manganese oxides synthesized nanophases has been systematically studied using XRD, SEM and EDX.

The preferred valence states of transition metals

1964 ◽  
Vol 17 (8) ◽  
pp. 833 ◽  
Author(s):  
JC Sheldon
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Heat Of Formation ◽  
Valence States ◽  
Elementary Transition ◽  
Binary Compounds ◽  
Transition Metal Fluorides ◽  
D Orbitals ◽  
Related Compounds ◽  
Valence Number

It is proposed that the valence number, n, for bonding in the elemental state may be estimated by n = rΔHf�/C, where r is half the interatomic distance, -ΔHf� is the heat of formation of the elemental state, and C is a constant and approximately 28 and 40 Ǻ kcal g-atom-1 for non-metals and metals respectively. It is shown that the valence states of the elementary transition metals, as given by n, correspond closely to the most stable oxidation states (MSOS) displayed in binary transition metal fluorides, chlorides, and related compounds. It is concluded that the trend of the MSOS of transition metal binary compounds results mainly from each metal possessing a preferred valence state, which is strongly determined by the availability of the (n-l)d orbitals for bonding as judged by their size relative to that of the ns and p orbitals.

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