The Outer-Coordination Sphere: Incorporating Amino Acids and Peptides as Ligands for Homogeneous Catalysts to Mimic Enzyme Function

Arginine‐Containing Ligands Enhance H2 Oxidation Catalyst Performance

“…If both proton and electron transfer steps are fast compared to turnover and reversible, then the ratio of their forward and reverse rates will change with pH and potential as expected for an equilibrium system. This suggests (2), and/or deprotonation (3) while Arg-Arg interactions may assist H 2 addition (1) and/or heterolytic cleavage (2) but are unlikely to directly deprotonate (3). The equilibrium potential for H 2 oxidation/ evolution shows the same pH dependence, and so the overpotential at E cat/2 will be invariant with pH, as noted with the H 2 -evolving catalyst [Ni(P Ph 2 N Bn 2 ) 2 ] 2+ in acetonitrile.…”

“…[2] The protein scaffold or outer coordination sphere of the enzyme controls dynamic switching processes, local pH, polarity, electrochemical potential, and the transport of reactants and products over long distances, making enzymes more active and selective than synthetic analogs. [3] Hydrogenases are a class of metalloenzymes that use abundant metals such as Ni and Fe to interconvert protons and electrons with H 2 , reactions that hold promise for the storage and recovery of intermittent sources of electricity such as solar and wind. [3] Hydrogenases are a class of metalloenzymes that use abundant metals such as Ni and Fe to interconvert protons and electrons with H 2 , reactions that hold promise for the storage and recovery of intermittent sources of electricity such as solar and wind.…”

“…[2] The outstanding performance of these naturally occurring catalysts has inspired a biomimetic approach to the development of synthetic catalyst systems. [3] Hydrogenases are a class of metalloenzymes that use abundant metals such as Ni and Fe to interconvert protons and electrons with H 2 , reactions that hold promise for the storage and recovery of intermittent sources of electricity such as solar and wind. [4] The protein scaffold transports H 2 , protons, and electrons, and controls the environment around the active site, [4] resulting in rapid turnover (up to ca.…”

Localizing Perturbations of the Racemic Equilibria Involving Dipicolinate‐Derived Lanthanide(III) Complexes

“…Beyond the incredibly important protein multiplexes of biology, multimolecular complexes of small molecules have significant applications in, among others, sensing, 1 catalysis, 2,3 and supramolecular chemistry. 4 Driven by their long excited state lifetimes, characteristic emission, and diverse chemistry, luminescent lanthanide, Ln(III), complexes have a long history of use as molecular probes.…”

Arginine‐Containing Ligands Enhance H2 Oxidation Catalyst Performance

“…[24b, 25] H 2 oxidation occurs clockwise. For [Ni II (P Cy 2 N Arg 2 ) 2 ] 8+ , COO À may influence H 2 addition (1), heterolytic cleavage(2), and/or deprotonation(3) while Arg-Arg interactions may assist H 2 addition (1) and/or heterolytic cleavage (2) but are unlikely to directly deprotonate (3). The steps are highlighted by gray dotted circles.…”