Mechanistic Features of Iridium Pincer Complex Catalyzed Hydrocarbon Dehydrogenation Reactions:  Inhibition upon Formation of a μ-Dinitrogen Complex

1998 ◽  
Vol 17 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Do W. Lee ◽  
William C. Kaska ◽  
Craig M. Jensen
Keyword(s):  
Pincer Complex ◽  
Dehydrogenation Reactions ◽  
Dinitrogen Complex

scholarly journals An electron poor iridium pincer complex for catalytic alkane dehydrogenation

2016 ◽  
Vol 45 (40) ◽  
pp. 15963-15969 ◽  
Author(s):  
Oleksandr O. Kovalenko ◽  
Ola F. Wendt
Keyword(s):  
Iridium Complex ◽  
Alkane Dehydrogenation ◽  
Pincer Complex ◽  
Dehydrogenation Reactions

A new electron deficient iridium complex demonstrates an improved TON in alkane transfer dehydrogenation reactions compared to similar pre-catalysts.

Selective dehydrogenation of alcohols and diols catalyzed by a dihydrido iridium PCP pincer complex

2001 ◽  
Vol 79 (5-6) ◽  
pp. 823-829 ◽  
Author(s):  
David Morales-Morales ◽  
Rocío Redón ◽  
Zhaohui Wang ◽  
Do W Lee ◽  
Cathleen Yung ◽  
...  
Keyword(s):  
Carbonyl Complex ◽  
Secondary Alcohols ◽  
Preparative Scale ◽  
Pincer Complex ◽  
Alcohol Dehydrogenation ◽  
Dehydrogenation Reactions ◽  
Pcp Pincer

The PCP pincer complex, IrH2{C6H3-2,6-(CH2P-t-Bu2)2} (1) catalyzes the transfer dehydrogenation of primary and secondary alcohols. Dehydrogenation occurs across the C—O bond rather than the C—C bonds and the corresponding aldehydes or ketones are obtained as the sole products arising from the dehydrogenation reactions. Methanol is an exception to this pattern of reactivity and undergoes only stoichiometric dehydrogenation with 1 to give the carbonyl complex, Ir(CO){C6H3-2,6-(CH2P-t-Bu2)2} (2). The products are obtained in nearly quantitative yields when the reactions are carried out in toluene solutions. Under the same conditions, 2,5-hexanediol is converted to the annulated product, 3-methyl-2-cyclopenten-1-one which has been isolated in 91% yield in a preparative scale reaction.Key words: alcohol, dehydrogenation, ketones, iridium pincer complex, annulation.

Carbocyclic Pincer Carbene Complexes of Ruthenium: Syntheses and Reversible Hydrogenation

2021 ◽  
Author(s):  
Nicholas Wiedmaier ◽  
Hartmut Schubert ◽  
Hermann A Mayer ◽  
Lars Wesemann
Keyword(s):  
Carbene Complexes ◽  
Carbene Complex ◽  
Pincer Complex

The ruthenium carbene pincer complex 2 was synthesized treating the benzo annulated cycloheptatriene bisphosphine 1 with RuCl3. Addition of three equivalents of hydrogen to the carbocyclic carbene complex 2 was...

scholarly journals Energetics of LOHC: Structure-Property Relationships from Network of Thermochemical Experiments and in Silico Methods

Hydrogen ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 101-121
Author(s):  
Sergey P. Verevkin ◽  
Vladimir N. Emel’yanenko ◽  
Riko Siewert ◽  
Aleksey A. Pimerzin
Keyword(s):  
In Silico ◽  
Quantum Chemical ◽  
Structure Property ◽  
Chemical Methods ◽  
Key Technology ◽  
Structure Property Relationships ◽  
Quantum Chemical Methods ◽  
Dehydrogenation Reactions ◽  
Storage Technologies ◽  
In Silico Methods

The storage of hydrogen is the key technology for a sustainable future. We developed an in silico procedure, which is based on the combination of experimental and quantum-chemical methods. This method was used to evaluate energetic parameters for hydrogenation/dehydrogenation reactions of various pyrazine derivatives as a seminal liquid organic hydrogen carriers (LOHC), that are involved in the hydrogen storage technologies. With this in silico tool, the tempo of the reliable search for suitable LOHC candidates will accelerate dramatically, leading to the design and development of efficient materials for various niche applications.

Csp3−H Activation without Chelation Assistance in an Iridium Pincer Complex Forming Cyclometallated Products

2017 ◽  
Vol 23 (8) ◽  
pp. 1748-1751 ◽  
Author(s):  
David A. Ahlstrand ◽  
Alexey V. Polukeev ◽  
Rocío Marcos ◽  
Mårten S. G. Ahlquist ◽  
Ola F. Wendt
Keyword(s):  
Pincer Complex

scholarly journals Electrolyte-Assisted Hydrogen Cycling in Lithium and Sodium Alanates at Low Pressures and Temperatures

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5868
Author(s):  
Jason Graetz ◽  
John J. Vajo
Keyword(s):  
Growth Parameters ◽  
Reaction Times ◽  
Hydrogen Uptake ◽  
Hydrogen Desorption ◽  
Reaction Rates ◽  
Rate Coefficients ◽  
Aluminum Hydrides ◽  
Dehydrogenation Reactions ◽  
Low Pressures ◽  
Sodium Alanates

An investigation of electrolyte-assisted hydrogen storage reactions in complex aluminum hydrides (LiAlH4 and NaAlH4) reveals significantly reduced reaction times for hydrogen desorption and uptake in the presence of an electrolyte. LiAlH4 evolves ~7.8 wt% H2 over ~3 h in the presence of a Li-KBH4 eutectic at 130 °C compared to ~25 h for the same material without the electrolyte. Similarly, NaAlH4 exhibits 4.8 wt% H2 evolution over ~4 h in the presence of a diglyme electrolyte at 150 °C compared to 4.4 wt% in ~15 h for the same material without the electrolyte. These reduced reaction times are composed of two effects, an increase in reaction rates and a change in the reaction kinetics. While typical solid state dehydrogenation reactions exhibit kinetics with rates that continuously decrease with the extent of reaction, we find that the addition of an electrolyte results in rates that are relatively constant over the full desorption window. Fitting the kinetics to an Avrami-Erofe’ev model supports these observations. The desorption rate coefficients increase in the presence of an electrolyte, suggesting an increase in the velocities of the reactant-product interfaces. In addition, including an electrolyte increases the growth parameters, primarily for the second desorption steps, resulting in the observed relatively constant reaction rates. Similar effects occur upon hydrogen uptake in NaH/Al where the presence of an electrolyte enables hydrogenation under more practical low temperature (75 °C) and pressure (50 bar H2) conditions.

scholarly journals Protonation Studies of a Mono-Dinitrogen Complex of Chromium Supported by a 12-Membered Phosphorus Macrocycle Containing Pendant Amines

2015 ◽  
Vol 54 (10) ◽  
pp. 4827-4839 ◽  
Author(s):  
Michael T. Mock ◽  
Aaron W. Pierpont ◽  
Jonathan D. Egbert ◽  
Molly O’Hagan ◽  
Shentan Chen ◽  
...  
Keyword(s):  
Dinitrogen Complex
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