Solution phase high repetition rate laser pump x-ray probe picosecond hard x-ray spectroscopy at the Stanford Synchrotron Radiation Lightsource.

We present a dedicated end-station for solution phase high repetition rate (MHz) picosecond hard x-ray spectroscopy at beamline 15-2 of the Stanford Synchrotron Radiation Lightsource. A high-power ultrafast ytterbium-doped fiber laser is used to photoexcite the samples at a repetition rate of 640 kHz, while the data acquisition operates at the 1.28 MHz repetition rate of the storage ring recording data in an alternating on-off mode.

Correction: X-ray absorption spectroscopy of exemplary platinum porphyrin and corrole derivatives: metal- ligand-centered oxidation.

[This corrects the article DOI: 10.1039/D1RA06151H.].

X-ray absorption spectroscopy of exemplary platinum porphyrin and corrole derivatives: metal- ligand-centered oxidation.

A combination of Pt L-edge X-ray absorption spectroscopy (EXAFS and XANES) and DFT (TPSS) calculations have been performed on powder samples of the archetypal platinum porphyrinoid complexes Pt[TCFPP], Pt[TCFPP]Cl, and Pt[TCFPC](Ar)(py), where TCFPP = -tetrakis(-trifluoromethylphenyl)porphyrinato and TCFPC = -tris(-trifluoromethylphenyl)corrolato. The three complexes yielded Pt L-edge energies of 11 566.0 eV, 11 567.

Electrocatalytic Alcohol Oxidation with Iron-Based Acceptorless Alcohol Dehydrogenation Catalyst.

Electrochemical and chemical studies reveal that the amido complex (PNHP)Fe(CO)(H)(X) (FeN , = 0, X = 0; Fe(H)(NH) , = 1, X = H; PNHP = bis[2-(diisopropylphosphino)ethyl]amine) is active for the electrocatalytic oxidation of isopropanol. At room temperature, the amido FeN dehydrogenates isopropanol to form acetone. The resulting amino hydride complex Fe(H)(NH) is subsequently oxidized by one electron at a low potential (-0.

Reactivity of NO with Porous and Conductive Copper Azobispyridine Metallopolymers.

We report the reactivity of copper azobispyridine (abpy) metallopolymers with nitrogen dioxide (NO). The porous and conductive [Cu(abpy)] mixed-valence metallopolymers undergo a redox reaction with NO, resulting in the disproportionation of NO gas. Solid- and gas-phase vibrational spectroscopy and X-ray analysis of the reaction products of the NO-dosed metallopolymer show evidence of nitrate ions and nitric oxide gas.

Effect of Redox Active Ligands on the Electrochemical Properties of Manganese Tricarbonyl Complexes.

The synthesis, structural characterization, and electrochemical behavior of the neutral Mn(azpy)(CO)(Br) 4 (azpy = 2-phenylazopyridine) complex is reported and compared with its structural analogue Mn(bipy)(CO)(Br) 1 (bipy = 2,2'-bipyridine). 4 exhibits reversible two-electron reduction at a mild potential (-0.93 V vs Fc in acetonitrile) in contrast to 1, which exhibits two sequential one-electron reductions at -1.

Fe-mediated HER vs NRR: Exploring Factors that Contribute to Selectivity in P Fe(N) (E = B, Si, C) Catalyst Model Systems.

Mitigation of the hydrogen evolution reaction (HER) is a key challenge in selective small molecule reduction catalysis. This is especially true of catalytic nitrogen (N) and carbon dioxide (CO) reduction reactions (NRR and CORR, respectively) using H/e currency. Here we explore, via DFT calculations, three iron model systems, P Fe (E = B, Si, C), known to mediate both NRR and HER, but with different selectivity depending on the identity of the auxiliary ligand.

Fe-Mediated Nitrogen Fixation with a Metallocene Mediator: Exploring p K Effects and Demonstrating Electrocatalysis.

Substrate selectivity in reductive multielectron/proton catalysis with small molecules such as N, CO, and O is a major challenge for catalyst design, especially where the competing hydrogen evolution reaction (HER) is thermodynamically and kinetically competent. In this study, we investigate how the selectivity of a tris(phosphine)borane iron(I) catalyst, PFe, for catalyzing the nitrogen reduction reaction (NRR, N-to-NH conversion) versus HER changes as a function of acid p K. We find that there is a strong correlation between p K and NRR efficiency.

Distant protonated pyridine groups in water-soluble iron porphyrin electrocatalysts promote selective oxygen reduction to water.

Fe(III)-meso-tetra(pyridyl)porphyrins are electrocatalysts for the reduction of dioxygen in aqueous acidic solution. The 2-pyridyl derivatives, both the triflate and chloride salts, are more selective for the desired 4e(-) reduction than the isomeric 4-pyridyl complexes. The inward-pointing pyridinium groups influence proton delivery despite their distance from the iron centre.

Electrocatalytic oxygen reduction by iron tetra-arylporphyrins bearing pendant proton relays.

Iron(III) meso-tetra(2-carboxyphenyl)porphine chloride (1) was investigated as a soluble electrocatalyst for the oxygen reduction reaction (ORR) in acetonitrile with [H(DMF)(+)]OTf(-). Rotating ring-disk voltammetry, spectroelectrochemistry, and independent reactions with hydrogen peroxide indicate that 1 has very high selectivity for reduction of O(2) to H(2)O, without forming significant amounts of H(2)O(2). Cyclic voltammetric measurements at high substrate/catalyst ratios (high oxygen pressure) allowed the estimation of a turnover frequency (TOF) of 200 s(-1) at -0.