Pyridinediimine Iron Dicarbonyl Complexes with Pendant Lewis Bases and Lewis Acids Located in the Secondary Coordination Sphere

2013 ◽  
Vol 2013 (22-23) ◽  
pp. 4008-4015 ◽  
Author(s):  
Zachary Thammavongsy ◽  
Micah E. LeDoux ◽  
Andrew G. Breuhaus-Alvarez ◽  
Takele Seda ◽  
Lev N. Zakharov ◽  
...  
Keyword(s):  
Coordination Sphere ◽  
Lewis Acids ◽  
Lewis Bases ◽  
Secondary Coordination Sphere

scholarly journals Mobility of Lewis acids within the secondary coordination sphere: toward a model for cooperative substrate binding

2020 ◽  
Vol 56 (86) ◽  
pp. 13105-13108
Author(s):  
John J. Kiernicki ◽  
Emily E. Norwine ◽  
Myles A. Lovasz ◽  
Matthias Zeller ◽  
Nathaniel K. Szymczak
Keyword(s):  
Coordination Sphere ◽  
Lewis Acids ◽  
Substrate Binding ◽  
Zinc Complexes ◽  
Secondary Coordination Sphere ◽  
Distance Dependence

Distance dependence of appended Lewis acids in N2H4 binding and deprotonation was evaluated within a series of zinc complexes.

scholarly journals Uncoupled Redox-Inactive Lewis Acids in the Secondary Coordination Sphere Entice Ligand-Based Nitrite Reduction

2018 ◽  
Vol 57 (16) ◽  
pp. 9601-9610 ◽  
Author(s):  
Kyle T. Burns ◽  
Walker R. Marks ◽  
Pui Man Cheung ◽  
Takele Seda ◽  
Lev N. Zakharov ◽  
...  
Keyword(s):  
Coordination Sphere ◽  
Lewis Acids ◽  
Nitrite Reduction ◽  
Secondary Coordination Sphere

scholarly journals Using internal electrostatic fields to manipulate the valence manifolds of copper complexes

2021 ◽  
Author(s):  
Alexander B. Weberg ◽  
Samuel P. McCollom ◽  
Laura M. Thierer ◽  
Michael R. Gau ◽  
Patrick J. Carroll ◽  
...  
Keyword(s):  
Coordination Sphere ◽  
Copper Complexes ◽  
Photophysical Properties ◽  
Redox Potentials ◽  
Electrostatic Effects ◽  
Electrostatic Fields ◽  
Secondary Coordination Sphere

Secondary coordination sphere electrostatic effects tune the valence manifolds of copper centers, impacting molecular geometries, photophysical properties, and redox potentials.

Spontaneous bond dissociation cascades induced by Ben clusters (n = 2,4)

2021 ◽  
Author(s):  
Eva Vos ◽  
Inés Corral ◽  
M. Merced Montero-Campillo ◽  
Otilia Mó ◽  
José Elguero ◽  
...  
Keyword(s):  
Lewis Acids ◽  
Lewis Bases ◽  
Bond Dissociation ◽  
Multireference Methods

Be4 clusters are very powerful Lewis acids leading to the total dissociation of all the bonds of the Lewis bases interacting with them. The product of the bond dissociation cascade possesses a hyper-coordinated center. Multireference methods are needed to correctly describe these complexes.

Building new discrete supramolecular assemblies through the interaction of iso-tellurazole N-oxides with Lewis acids and bases

2017 ◽  
Vol 203 ◽  
pp. 187-199 ◽  
Author(s):  
Peter C. Ho ◽  
Hilary A. Jenkins ◽  
James F. Britten ◽  
Ignacio Vargas-Baca
Keyword(s):  
Electron Acceptor ◽  
Lewis Acids ◽  
Heterocyclic Carbenes ◽  
Supramolecular Assemblies ◽  
Triphenyl Phosphine ◽  
Tellurium Atom ◽  
Lewis Bases ◽  
Acids And Bases ◽  
Lewis Acids And Bases

The supramolecular macrocycles spontaneously assembled by iso-tellurazole N-oxides are stable towards Lewis bases as strong as N-heterocyclic carbenes (NHC) but readily react with Lewis acids such as BR3 (R = Ph, F). The electron acceptor ability of the tellurium atom is greatly enhanced in the resulting O-bonded adducts, which consequently enables binding to a variety of Lewis bases that includes acetonitrile, 4-dimethylaminopyridine, 4,4′-bipyridine, triphenyl phosphine, a N-heterocyclic carbene and a second molecule of iso-tellurazole N-oxide.

scholarly journals Ligand-Based H2 Transfer with Dihydrazonopyrrole Complexes of Nickel

2020 ◽  
Author(s):  
Andrew McNeece ◽  
Kate Jesse ◽  
Alexander S. Filatov ◽  
Joseph Schneider ◽  
John Anderson
Keyword(s):  
Coordination Sphere ◽  
Computational Analysis ◽  
Metal Center ◽  
Electron Storage ◽  
Precise Control ◽  
Secondary Coordination Sphere ◽  
Proton Donors ◽  
Redox Change

Biology uses precise control over proton, electron, H-atom, or H<sub>2</sub> transfer to mediate challenging reactivity. While synthetic complexes have made incredible strides in replicating secondary coordination electron or proton donors, there are comparatively fewer examples of ligands that can mediate both proton and electron storage. Rarer still are ligands that can store full H<sub>2</sub> equivalents. Here we report a dihydrazonopyrrole Ni complex where an H<sub>2</sub> equivalent can be stored on the ligand periphery without any redox change at the metal center. This ligand-based storage of H<sub>2</sub> can be leveraged for catalytic hydrogenations. Kinetic and computational analysis suggests a rate determining H<sub>2</sub> binding step followed by comparatively facile H–H scission to hydrogenate the ligand. This system is an unusual example where a synthetic system can mimic biology’s ability to mediate H<sub>2</sub> transfer via secondary coordination sphere-based processes.

scholarly journals Beyond the Active Site: Mechanistic Investigations of the Role of the Secondary Coordination Sphere and Beyond on Multi-Electron Electrocatalytic Reactions and Their Relations Between Kinetics and Thermodynamics

2020 ◽  
Author(s):  
Vincent Wang
Keyword(s):  
Thermodynamic Parameters ◽  
Coordination Sphere ◽  
Active Site ◽  
Rate Constants ◽  
Reduction Reaction ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Secondary Coordination Sphere ◽  
Catalytic Rate ◽  
Rate Limiting

<p>The development of an electrocatalyst with a rapid turnover frequency, low overpotential and long-term stability is highly desired for fuel-forming reactions, such as water splitting and CO<sub>2</sub> reduction. The findings of the scaling relationships between the catalytic rate and thermodynamic parameters over a wide range of electrocatalysts in homogeneous and heterogeneous systems provide useful guidelines and predictions for designing better catalysts for those redox reactions. However, such relationships also suggest that a catalyst with a high catalytic rate is typically associated with a high overpotential for a given reaction. Inspired by enzymes, the introduction of additional interactions through the secondary coordination sphere beyond the active site, such as hydrogen-bonding or electrostatic interactions, have been shown to offer a promising avenue to disrupt these unfavorable relationships. Herein, we further investigate the influence of these cooperative interactions on the faster chemical steps, in addition to the rate-limiting step widely examined before, for molecular electrocatalysts with the structural and electronic modifications designed to facilitate the dioxygen reduction reaction, CO<sub>2</sub> reduction reaction and hydrogen evolving reaction. Based on the electrocatalytic kinetic analysis, the rate constants for faster chemical steps and their correlation with the corresponding thermodynamic parameters are evaluated. The results suggest that the effects of the secondary coordination sphere and beyond on these fuel-forming reactions are not necessarily beneficial for promoting all chemical steps and no apparent relation between rate constants and thermodynamic parameters are found in some cases studied here, which may implicate the design of electrocatalysts in the future. Finally, these analyses demonstrate that the characteristic features for voltammograms and foot-of-the-wave-analysis plots are associated with the specific kinetic phenomenon among these multi-electron electrocatalytic reactions, which provides a useful framework to probe the insights of chemical and electronic modifications on the catalytic steps quantitatively (i.e. kinetic rate constants) and to optimize some of critical steps beyond the rate-limiting step.</p>

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