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...
The content of this RSS Feed (c) The Royal Society of Chemistry

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...
The content of this RSS Feed (c) The Royal Society of Chemistry

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...