Synthesis of Sulfur- andNitrogen-Bridged Diiron Complexesand Catalytic Behavior toward Hydrazines

Synthesis of Sulfur- and
Nitrogen-Bridged Diiron Complexes
and Catalytic Behavior toward Hydrazines:

Organometallics

DOI: 10.1021/om300134t

Site-Selective X-ray Spectroscopy on an Asymmetric Model Complex of the [FeFe] Hydrogenase Active Site

Site-Selective X-ray Spectroscopy
on an Asymmetric
Model Complex of the [FeFe] Hydrogenase Active Site:

Inorganic Chemistry

DOI: 10.1021/ic2024154

Photo-induced oxidation of [FeII(N4Py)CH3CN] and related complexes

Photo-induced oxidation of [FeII(N4Py)CH3CN] and related complexes:

Dalton Trans., 2012, Accepted Manuscript
DOI: 10.1039/C2DT30392B, Paper

Apparao Draksharapu, Qian Li, Gerard Roelfes, Wesley Browne

The photochemistry of the complexes [Fe(N4Py)(CH3CN)](ClO4)2 (1) , where N4Py is (1,1-di(pyridin-2-yl)-N,N-bis(pyridin-2-ylmethyl)methanamine) and [Fe(MeN4Py)(CH3CN)](ClO4)2 (2), where MeN4Py (1,1-di(pyridin-2-yl)-N,N-bis(pyridin-2-ylmethyl)ethanamine), in water, dichloromethane and methanol, is described. Under UV or visible irradiation visible irradiation both 1 and 2 undergo enhancement of the rate of outer sphere electron transfer to 3O2 to yield the superoxide radical anion and the complexes in the Fe(III) redox state. Addition of ascorbic acid to the photoproduct leads to a recovery of the initial UV/Vis spectrum of 1 and 2, indicating that ligand oxidation does not occur.

we should learn to make this ligand.  The Npy4 theme would be good literature talk.

Complexes of Cu(I) supported by a tris(ketimine) tripod

Complexes of Cu(I) supported by a tris(ketimine) tripod:

Dalton Trans., 2012, Accepted Manuscript
DOI: 10.1039/C2DT30101F, Communication

Jeremiah Scepaniak, Guang Wu, Trevor W. Hayton
Arylation of tris(2-benzylnitrile)amine with PhLi, followed by aqueous work-up, results in the formation of a tripodal tris(ketamine) scaffold, N(ArCNHPh)3. N(ArCNHPh)3 readily coordinates a number of CuI salts, generating complexes that...
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Perhaps interesting to Shishian

ModelStudies of Methyl CoM Reductase:Methane Formation via CH3–S Bond Cleavage of Ni(I)Tetraazacyclic Complexes Having Intramolecular Methyl Sulfide Pendants

Model
Studies of Methyl CoM Reductase:
Methane Formation via CH3–S Bond Cleavage of Ni(I)
Tetraazacyclic Complexes Having Intramolecular Methyl Sulfide Pendants:

Inorganic Chemistry

DOI: 10.1021/ic300017k

Antagonism between Extreme Negative Linear Compression and Spin Crossover in [Fe(dpp)2(NCS)2]⋅py

Antagonism between Extreme Negative Linear Compression and Spin Crossover in [Fe(dpp)2(NCS)2]⋅py:

A scissor-like geometric mechanism is responsible for the strongest negative linear compression effect yet observed in a molecular material, [Fe(dpp)₂(NCS)₂]⋅py (see picture; dpp=dipyrido[3,2-a:2′3′-c]phenazine), C gray, N blue, S yellow, Fe red). The same mechanism is also responsible for suppressing the high-spin to low-spin transition under pressure.

The Stereochemical Course and Mechanism of the IspH Reaction

The Stereochemical Course and Mechanism of the IspH Reaction:

On the right path: The stereochemcial course of the IspH reaction, the last reaction in the deoxyxylulose phosphate pathway to terpenes, was investigated in feeding experiments with deuterated isotopologues of 1-deoxy-D-xylulose. The results support an enzyme mechanism for IspH that involves a previously suggested metallacyclopropane intermediate.

New function for Fe-S clusters

Organometallic Ruthenium and Iridium Transfer-Hydrogenation Catalysts Using Coenzyme NADH as a Cofactor

Organometallic Ruthenium and Iridium Transfer-Hydrogenation Catalysts Using Coenzyme NADH as a Cofactor:

Artificial enzymes: Half-sandwich arene ruthenium(II) and cyclopentadienyl iridium(III) complexes containing N,N-chelated ligands can use NADH as a source of hydride for the reduction of ketones (see picture). Moreover, cyclopentadienyl phenanthroline iridium(III) derivatives at micromolar concentrations are robust catalysts for the production of H₂ from NADH in water and can raise the NAD⁺/NADH ratio in cancer cells.
Sadler et al.

Homogeneous CO2 Reduction by Ni(cyclam) at a Glassy Carbon Electrode

Homogeneous CO2 Reduction by Ni(cyclam)
at a Glassy Carbon Electrode:

Inorganic Chemistry

DOI: 10.1021/ic3001619

Experimental Study of Reductive Elimination of H2 from Rhodium Hydride Species

Experimental Study of
Reductive Elimination of H2 from Rhodium Hydride Species:

Organometallics

DOI: 10.1021/om2009759

Air-Stable, Highly Fluorescent Primary Phosphanes

Air-Stable, Highly Fluorescent Primary Phosphanes:

 

Light without fright: A synthetic route to fluorescent primary phosphanes (RPH₂) that are resistant to air oxidation both in the solid state and in chloroform solution is described. These versatile precursors undergo hydrophosphination to give tripodal ligands and subsequently fluorescent transition-metal complexes.

Reversible hydrogen storage using CO2 and a proton-switchable iridium catalyst in aqueous media under mild temperatures and pressures

Reversible hydrogen storage using CO2 and a proton-switchable iridium catalyst in aqueous media under mild temperatures and pressures:

Reversible hydrogen storage using CO2 and a proton-switchable iridium catalyst in aqueous media under mild temperatures and pressures

Nature Chemistry.
doi:10.1038/nchem.1295

Authors: Jonathan F. Hull, Yuichiro Himeda, Wan-Hui Wang, Brian Hashiguchi, Roy Periana, David J. Szalda, James T. Muckerman & Etsuko Fujita
When operating at near-ambient conditions, using water as a solvent, a high-turnover iridium catalyst enables a reversible hydrogen storage system that uses carbon dioxide, formate and formic acid. Proton-responsive ligands in the catalyst allow it to be turned on or off by controlling the pH of the solution.

Pendant Amine Bases Speed up Proton Transfers to Metals by Splitting the Barriers

Pendant Amine Bases Speed up Proton Transfers to Metals by Splitting the Barriers:

Chem. Commun., 2012, Accepted Manuscript
DOI: 10.1039/C2CC00044J, Communication

Ying Wang, Mei Wang, Licheng Sun, Marten Ahlquist
By using density functional theory on [FeFe]-hydrogenase mimics we find that pendant amine bases speed up the proton transfer to and from metal centers by dividing the high free energy...
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Cationic Ti(IV) and neutral Ti(III) titanocene-phosphinoaryloxide frustrated Lewis pairs: hydrogen activation and catalytic amine-borane dehydrogenation

Cationic Ti(IV) and neutral Ti(III) titanocene-phosphinoaryloxide frustrated Lewis pairs: hydrogen activation and catalytic amine-borane dehydrogenation:

Dalton Trans., 2012, Accepted Manuscript
DOI: 10.1039/C2DT30168G, Paper

Duncan Wass
Titanium-phosphorus frustrated Lewis pairs (FLPs) based on titanocene-phosphinoaryloxide complexes have been synthesised. The cationic titanium(IV) complex [Cp2TiOC6H4P(tBu)2][B(C6F5)4] 2 reacts with hydrogen to yield the reduced titanium(III) complex [Cp2TiOC6H4PH(tBu)2][B(C6F5)4] 4. The...
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Electron vs Energy Transfer in Arrays Featuring Two Bodipy Chromophores Axially Bound to a Sn(IV) Porphyrin via a Phenolate or Benzoate Bridge

Electron vs Energy Transfer
in Arrays Featuring Two
Bodipy Chromophores Axially Bound to a Sn(IV) Porphyrin via a Phenolate
or Benzoate Bridge:

Inorganic Chemistry

DOI: 10.1021/ic2026472

Characterization of Photochemical Processes for H2 Production by CdS Nanorod–[FeFe] Hydrogenase Complexes

Characterization of Photochemical
Processes for H2 Production by CdS Nanorod–[FeFe]
Hydrogenase Complexes:

Journal of the American Chemical Society

DOI: 10.1021/ja2116348

Selective Electrocatalytic Reduction of CO2 to Formate by Water-Stable Iridium Dihydride Pincer Complexes

Selective Electrocatalytic
Reduction of CO2 to Formate by Water-Stable Iridium Dihydride
Pincer Complexes:

Journal of the American Chemical Society

DOI: 10.1021/ja300543s

Electrocatalytic Oxygen Reduction by Iron Tetra-arylporphyrins Bearing Pendant Proton Relays

Electrocatalytic Oxygen
Reduction by Iron Tetra-arylporphyrins
Bearing Pendant Proton Relays:

Journal of the American Chemical Society

DOI: 10.1021/ja211987f

Lewis Acid Base Reactions between Boron Trifluoride and Complex Oxoanions as a Versatile Access to Fluorooxoanions: Synthesis of Sodium (Trifluoroborato)sulfate

Lewis Acid Base Reactions between Boron Trifluoride and Complex Oxoanions as a Versatile Access to Fluorooxoanions: Synthesis of Sodium (Trifluoroborato)sulfate:

Abstract Na₂SO₄BF₃, synthesized in a closed vessel from BF₃ and Na₂SO₄ at 603 K, crystallizes in the triclinic space group P (a = 6.6033(2), b = 6.6328(2), c = 6.6349 (1) Å, α = 84.542(2), β = 84.458(1) and γ = 65.762(1)°). The novel fluorooxo anion [SO₄BF₃]^2– displays a structure similar to the disulfate anion S₂O₇^2–. Heating the title compound in the absence of BF₃ in the gas phase leads to decomposition even at 553 K, which is below the temperature of synthesis under BF₃ pressure.

Synthesis, crystal structure, spectroscopic and electrochemical properties, and H2-evolving activity of a new [PtCl(terpyridine)]+ derivative with viologen-like redox properties

Synthesis, crystal structure, spectroscopic and electrochemical properties, and H2-evolving activity of a new [PtCl(terpyridine)]+ derivative with viologen-like redox properties:

Dalton Trans., 2012, Advance Article DOI: 10.1039/C2DT12209J, Paper

Masayuki Kobayashi, Shigeyuki Masaoka, Ken Sakai
A new Pt(II)-based metalloviologen as an H₂-evolving catalyst was developed, and its electrochemical and photochemical properties were investigated.

Enantiopure C1-Symmetric Bis(imino)pyridine Cobalt Complexes for Asymmetric Alkene Hydrogenation

Enantiopure C1-Symmetric
Bis(imino)pyridine Cobalt Complexes for Asymmetric Alkene Hydrogenation:

Journal of the American Chemical Society

DOI: 10.1021/ja300503k

Mechanisms for CO Production from CO2 Using Reduced Rhenium Tricarbonyl Catalysts

Mechanisms for CO Production
from CO2 Using
Reduced Rhenium Tricarbonyl Catalysts:

Journal of the American Chemical Society

DOI: 10.1021/ja2105834

Reversible H2 Addition across a Nickel–Borane Unit as a Promising Strategy for Catalysis

Reversible H2 Addition across a Nickel–Borane
Unit as a Promising Strategy for Catalysis:

Journal of the American Chemical Society

DOI: 10.1021/ja211419t

A 4,5-Diphosphino-Substituted Imidazolium Salt: A Building Block for the Modular Synthesis of Mixed Diphosphine–NHC Heterometallic Complexes

A 4,5-Diphosphino-Substituted Imidazolium Salt: A Building Block for the Modular Synthesis of Mixed Diphosphine–NHC Heterometallic Complexes:

Fused in the same molecule! An N-heterocyclic carbene and a diphosphine are generated and used in the modular synthesis of a variety of target heterometallic complexes. The experimental approach involves formation of a unique 4,5-bis(diphenylphosphino)-1,3-dimethyl-imidazolium salt, simply by starting from 1-methylimidazole (see scheme; M¹=Cr, Mn; M²=Au, Rh, Pd; LiHMDS=LiN(SiMe₃)₂).

Chem. Eur. J

Molybdenum-catalyzed reduction of molecular dinitrogen under mild reaction conditions

Molybdenum-catalyzed reduction of molecular dinitrogen under mild reaction conditions:

Dalton Trans., 2012, Accepted Manuscript
DOI: 10.1039/C2DT30105A, Perspective

Yoshiaki Nishibayashi
Quite recently, we have found two nitrogen fixation systems catalyzed by the molybdenum-dinitrogen complexes under mild reaction conditions; one is the transformation of molecular dinitrogen into its synthetic equivalent of...

Hydrogenolysis Goes Bio: From Carbohydrates and Sugar Alcohols to Platform Chemicals

Hydrogenolysis Goes Bio: From Carbohydrates and Sugar Alcohols to Platform Chemicals:

Abstract

In view of the diminishing oil resources and the ongoing climate change, the use of efficient and environmentally benign technologies for the utilization of renewable resources has become indispensible. Therein, hydrogenolysis reactions offer a promising possibility for future biorefinery concepts. These reactions result in the cleavage of CC and CO bonds by hydrogen and allow direct access to valuable platform chemicals already integrated in today’s value chains. Thus, hydrogenolysis bears the potential to bridge currently available technologies and future biomass-based refinery concepts. This Review highlights past and present developments in this field, with special emphasis on the direct utilization of cellulosic feedstocks.

Hydrogenolysis of renewable feedstocks allows direct access to valuable platform chemicals already integrated in today’s value chains. Transformations based on hydrogenolysis bear the potential to bridge available technologies and future biorefinery concepts. This Review highlights developments in this field, with special emphasis on the direct transformation of cellulose and sugars.

Activation of H–Hand H–O Bonds at Phosphoruswith Diiron Complexes Bearing Pyramidal Phosphinidene Ligands

Activation of H–H
and H–O Bonds at Phosphorus
with Diiron Complexes Bearing Pyramidal Phosphinidene Ligands:

Inorganic Chemistry

DOI: 10.1021/ic2026945

Simple Ligand Effects Switch a Hydrogenase Mimic between H2 and O2 Activation

Simple Ligand Effects Switch a Hydrogenase Mimic between H2 and O2 Activation:

Abstract

Herein, we report a [NiRu] biomimetic system for O₂-tolerant [NiFe]hydrogenases and demonstrate that electron donation to the [NiRu] center can switch the system between the activation of H₂ and O₂ through simple ligand effects by using hexamethylbenzene and pentamethylcyclopentadienyl ligands, respectively. Furthermore, we present the synthesis and direct observations of a [NiRu]–peroxo species, which was formed by the oxygenation of a Ni-SIa model [NiRu] complex, that we propose as a biomimetic analogue of O₂-bound species (OBS) of O₂-tolerant [NiFe]hydrogenases. The [NiRu]–peroxo complex was fully characterized by X-ray analysis, X-ray photoelectron spectroscopy (XPS), mass spectrometry, and ¹H NMR spectroscopy. The OBS analogue was capable of oxidizing p-hydroquinone and sodium borohydride to turn back into the Ni-SIa model complex.

At the flick of a switch: A [NiRu] biomimetic system for O₂-tolerant [NiFe]hydrogenases was constructed. Electron donation to the [NiRu] center switched the system between activation of H₂ and O₂. Furthermore, a [NiRu]–peroxo species, which was capable of oxidizing p-hydroquinone, was considered as a biomimetic analogue of O₂-bound species (OBS) of O₂-tolerant [NiFe]hydrogenases.