scholarly journals Late Transition Metal (LTM)-NHC Catalyzed Transformations of Renewable Chemicals to Fine Chemicals, Fuels, and Intermediates

2021 ◽  
Author(s):  
Kurra Mohan ◽  
Bollikolla Hari Babu ◽  
Khandapu Bala Murali Krishna ◽  
Kotra Vijay ◽  
Varala Ravi

This title of the book chapter deals with the late transition metal-NHC (N-heterocyclic carbene) catalyzed transformations of renewable chemicals, i.e., bio-mass resources (carbohydrates/vegetable oils/natural products) into useful chemicals via oxidation, hydrogenation, dehydration, polymerization, hydrolysis, etc. along with brief introductory notes on late transition metals, carbenes, and renewable chemicals for better understanding to the reader.

2014 ◽  
Vol 4 (9) ◽  
pp. 2724-2740 ◽  
Author(s):  
Martino Rimoldi ◽  
Antonio Mezzetti

Grafting, quo vadis? The reasons for the aggregation of late transition metal complexes on oxide supports under reducing conditions and/or in the presence of π-accepting ligands are discussed, and strategies are suggested to prevent it.


2021 ◽  
Author(s):  
Sujoy Rana ◽  
Jyoti Prasad Biswas ◽  
Sabarni Paul ◽  
Aniruddha Paik ◽  
Debabrata Maiti

The promising aspects of iron in synthetic chemistry are being explored for three-four decades as a green and eco-friendly alternative to late transition metals. This present review unveils these rich iron-chemistry towards different transformations.


2014 ◽  
Vol 53 (7) ◽  
pp. 3307-3310 ◽  
Author(s):  
Alice K. Hui ◽  
Brian J. Cook ◽  
Daniel J. Mindiola ◽  
Kenneth G. Caulton

2019 ◽  
Vol 55 (85) ◽  
pp. 12797-12800 ◽  
Author(s):  
Hector Prats ◽  
Juan José Piñero ◽  
Francesc Viñes ◽  
Stefan T. Bromley ◽  
Ramón Sayós ◽  
...  

Transition Metal Carbides (TMCs) are proposed as viable replacements for scarce and expensive late Transition Metals (TMs) for heterogeneous catalysis involving hydrogenation reactions or steps.


Author(s):  
Samuel K. Riddle ◽  
Timothy R. Wilson ◽  
Malavikha Rajivmoorthy ◽  
M. E. Eberhart

For the better part of a century researchers across disciplines have sought to explain the crystallography of the elemental transition metals: hexagonal close packed, body centered cubic, and face centered cubic in a form similar to that used to rationalize the structure of organic molecules and inorganic complexes. Pauling himself tried with limited success to address the origins of transition metal stability. These early investigators were handicapped, however, by incomplete knowledge regarding the structure of metallic charge density. Here we exploit modern approaches to charge analysis to first comprehensively describe transition metal charge density. Then, we use topological partitioning and quantum mechanically rigorous treatments of kinetic energy to account for the structure of the density as arising from the interactions between metallic tetrahedra. We argue that the crystallography of the early transition metals results from charge transfer from the so called “octahedral” to “tetrahedral holes” while the face centered cubic structure of the late transition metals is a consequence of antibonding interactions that increase octahedral hole kinetic energy.


2020 ◽  
Author(s):  
Marti Lopez ◽  
Francesc Vines ◽  
Michael Nolan ◽  
Frances Illas

Previous work has shown that doping the TiC(001) surface with early transition metals significantly affects CO<sub>2</sub> adsorption and activation which opens a possible way to control this interesting chemistry. In this work we explore other possibilities which include non-transition metals elements (Mg, Ca, Sr, Al, Ga, In, Si, Sn) as well as late transition metals (Pd, Pt, Rh, Ir) and lanthanides (La, Ce) often used in catalysis. Using periodic slab models with large supercells and state-of-the-art density functional theory (DFT) based calculations, we show that, in all the studied cases, CO<sub>2</sub> appears as bent and, hence, activated. However, the effect is especially pronounced for dopants with large ionic crystal radii. These can increase desorption temperature by up to 230K, almost twice the value predicted when early transition metals are used as dopants. However, a detailed analysis of the results shows that the main effect does not come from electronic structure perturbations but from the distortion that the dopant generates into the surface atomic structure. A simple descriptor is proposed that would allow predicting the effect of the dopant on the CO<sub>2</sub> adsorption energy in transition metal carbide surfaces without requiring DFT calculations.


Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5396
Author(s):  
Samuel K. Riddle ◽  
Timothy R. Wilson ◽  
Malavikha Rajivmoorthy ◽  
Mark E. Eberhart

For the better part of a century researchers across disciplines have sought to explain the crystallography of the elemental transition metals: hexagonal close packed, body centered cubic, and face centered cubic in a form similar to that used to rationalize the structure of organic molecules and inorganic complexes. Pauling himself tried with limited success to address the origins of transition metal stability. These early investigators were handicapped, however, by incomplete knowledge regarding the structure of metallic electron density. Here, we exploit modern approaches to electron density analysis to first comprehensively describe transition metal electron density. Then, we use topological partitioning and quantum mechanically rigorous treatments of kinetic energy to account for the structure of the density as arising from the interactions between metallic polyhedra. We argue that the crystallography of the early transition metals results from charge transfer from the so called “octahedral” to “tetrahedral cages” while the face centered cubic structure of the late transition metals is a consequence of anti-bonding interactions that increase octahedral hole kinetic energy.


2020 ◽  
Author(s):  
Marti Lopez ◽  
Francesc Vines ◽  
Michael Nolan ◽  
Frances Illas

Previous work has shown that doping the TiC(001) surface with early transition metals significantly affects CO<sub>2</sub> adsorption and activation which opens a possible way to control this interesting chemistry. In this work we explore other possibilities which include non-transition metals elements (Mg, Ca, Sr, Al, Ga, In, Si, Sn) as well as late transition metals (Pd, Pt, Rh, Ir) and lanthanides (La, Ce) often used in catalysis. Using periodic slab models with large supercells and state-of-the-art density functional theory (DFT) based calculations, we show that, in all the studied cases, CO<sub>2</sub> appears as bent and, hence, activated. However, the effect is especially pronounced for dopants with large ionic crystal radii. These can increase desorption temperature by up to 230K, almost twice the value predicted when early transition metals are used as dopants. However, a detailed analysis of the results shows that the main effect does not come from electronic structure perturbations but from the distortion that the dopant generates into the surface atomic structure. A simple descriptor is proposed that would allow predicting the effect of the dopant on the CO<sub>2</sub> adsorption energy in transition metal carbide surfaces without requiring DFT calculations.


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