Well-ordered mesostructured silica and titania films were prepared using poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide) triblock copolymer species (Pluronic P123) as the structure-directing agents. By varying the volume ratio between the copolymer and inorganic components of the precursor solution, silica and titania thin films with cubic, 2D hexagonal, and lamellar mesostructures were prepared. The regions over which the three phases were obtained correspond well with those of the water−block copolymer binary phase diagram when considered in terms of the volume fraction of copolymer incorporated. In particular, a cubic mesostructure with crystalline TiO2 (anatase) in the walls, stable to 400 °C, was synthesized.

General Predictive Syntheses of Cubic, Hexagonal, and Lamellar Silica and Titania Mesostructured Thin Films§

Cooperative catalysis with first-row transition metals holds much promise for future developments regarding sustainable, selective transformations, including e.g. alkenes, dienes and a variety of small molecules such as CO2, N2 and water. This non-exhaustive analysis of the current state-of-the-art aims to give a comprehensive overview of the various design strategies and applications of first-row transition metal cooperative reactivity and to provide leads for new research initiatives in order to expand this emerging field. The main aspects covered involve bimetallic cooperativity, redox-noninnocent ligands in combination with first-row transition metal complexes, otherwise reactive or noninnocent scaffolds that can induce metal-ligand bifunctional substrate activation and the design of adaptive ligands and complexes thereof, wherein hemilability is a key factor for selective reactivity. The metals under review are primarily the late transition metals Fe, Co, Ni and Cu.

http://homkat.nl/Highlights/Articles/van%20der%20Vlugt%20EurJIC%202012%20363.pdf

Cooperative catalysis with first-row late transition metals

The tetradentate ligand N,N‘-bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,2-phenylenediamine, H4L1, has been prepared, and its square planar complexes [CuII(L3)] and [ZnII(L3)] have been synthesized from the reaction of H4L1 with [CuI(NCCH3)4](ClO4) or Zn(BF4)2·2H2O in methanol in the presence of air. The dianion (L3)2- represents the two-electron oxidized form of (L1)4-, namely N,N‘-bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,2-diiminoquinone. Complexes [CuII(L3)]·CH3CN and [Zn(L3)]·CH3CN have been characterized by X-ray crystallography, EPR spectroscopy, and magnetochemistry; [CuII(L3)] has an S = 1/2 ground state, and [Zn(L3)] is diamagnetic. Cyclic voltammetry established that both complexes undergo two successive reversible one-electron oxidations and two successive reversible one-electron reductions. Thus, the coordinated ligand exists in five oxidation levels. The species [MII(L4)]PF6 (M = CuII, ZnII) and [MII(L5)](ClO4)2 (M = CuII, ZnII) have been isolated and characterized by UV/vis, EPR, and 1H NMR spe...

Aerobic Oxidation of Primary Alcohols (Including Methanol) by Copper(II)− and Zinc(II)−Phenoxyl Radical Catalysts

Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies

Electron(ic) banking : First‐row transition metals can be given a noble character by redox‐active ligands, thus enabling two‐electron oxidative addition and reductive elimination steps (see scheme) A recently reported cobalt‐mediated Negishi‐type cross‐coupling reaction provides an illustrative example of this concept and reveals its potential to develop new catalytic reactions with cheap, abundant metals

Ligands that Store and Release Electrons during Catalysis

The relative orientation of the two magnetic orbitals, the CuII d x 2-y 2 orbital and the half-occupied π orbital of the tyrosyl radical, is the key to answering the question in the title. The arrangement shown (CuII -O-C bond angle of about 130° and a dihedral angle of about 90° between the x,y plane of the CuII polyhedron and the tyrosyl ring plane) leads to an overlap of the orbitals, which results in a singlet ground state.

Linda Ould-Moussa

Papers

Why Does the Active Form of Galactose Oxidase Possess a Diamagnetic Ground State

Phenoxyl radical complexes of chromium(III), manganese(III), cobalt(III), and nickel(II)

Warum hat die aktive Form der Galactose-Oxidase einen diamagnetischen Grundzustand?