6.1.2. Aqueous V(III) Chemistry 877 6.1.3. Oxidation State of Vanadium in Tunicates 878 6.1.4. Uptake of Vanadate into Tunicates 879 6.1.5. Vanadium Binding Proteins: Vanabins 879 6.1.6. Model Complexes and Their Chemistry 880 6.1.7. Catechol-Based Model Chemistry 880 6.1.8. Vanadium Sulfate Complexes 881 6.2. Fan Worm Pseudopotamilla occelata 883 7. Vanadium Nitrogenase 883 7.1. Nitrogenases 883 7.2. Biochemistry of Nitrogenase 884 7.3. Clusters in Nitrogenase and Model Systems: Structure and Reactivity 885

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The chemistry and biochemistry of vanadium and the biological activities exerted by vanadium compounds.

A.L.-P. thanks CSIC for a contract under the JAE-doctor
program. Financial support by PLE2009 project from MCIINN
and Consolider-Ingenio 2010 (proyecto MULTICAT) are also
acknowledged.

Gold-catalyzed carbon-heteroatom bond-forming reactions.

5-Methylcytosine can be converted to 5-hydroxymethylcytosine (5hmC) in mammalian DNA by the ten-eleven translocation (TET) enzymes. We introduce oxidative bisulfite sequencing (oxBS-Seq), the first method for quantitative mapping of 5hmC in genomic DNA at single-nucleotide resolution. Selective chemical oxidation of 5hmC to 5-formylcytosine (5fC) enables bisulfite conversion of 5fC to uracil. We demonstrate the utility of oxBS-Seq to map and quantify 5hmC at CpG islands (CGIs) in mouse embryonic stem (ES) cells and identify 800 5hmC-containing CGIs that have on average 3.3% hydroxymethylation. High levels of 5hmC were found in CGIs associated with transcriptional regulators and in long interspersed nuclear elements, suggesting that these regions might undergo epigenetic reprogramming in ES cells. Our results open new questions on 5hmC dynamics and sequence-specific targeting by TETs.

https://science.sciencemag.org/content/sci/early/2012/04/25/science.1220671.full.pdf

Quantitative Sequencing of 5-Methylcytosine and 5-Hydroxymethylcytosine at Single-Base Resolution

Oxidative chemistry of nitric oxide: the roles of superoxide, peroxynitrite, and carbon dioxide

Catalytic oxidation of hydrocarbons with hydrogen peroxide by vanadium-based polyoxometalates

Oxidation of a variety of saturated and unsaturated primary and secondary alcohols by tetraoxoruthen-ate(VI), [RuO4]2–, tetraoxoruthenate(VII), [RuO4]–, barium trans-trioxodihydroxoruthenium(VI), trans-Ba[Ru(OH)2O3], dioxotrichlororuthenate(VI), [RuO2Cl3]–, and dioxodichlorobipyridylruthenate(VI), [RuO2(bipy)Cl2], has been studied; [RuO4]2–may be used catalytically in conjunction with [S2O8]2– under basic aqueous conditions. For some of these systems, the oxidation of several aldehydes and amines were also examined. Both [RuO4]2–and [RuO4]– oxidise primary alcohols to carboxylic acids and secondary alcohols to ketones; the reactivity of these reagents towards unsaturated alcohols was studied in particular. The new species [PPh4][RuO2Cl3] and also [RuO2(bipy)Cl2] cleanly oxidise a wide range of alcohols to aldehydes and ketones without attack of double bonds. Ba[Ru(OH)2O3] functions as a heterogeneous oxidant in dichloromethane, oxidising only the most reactive alcohols to aldehydes.

Oxo complexes of ruthenium(VI) and (VII) as organic oxidants

The presence of a peroxocarbonate species, likely to be HCO4– in pH-dependent equilibrium with CO42–, in solutions of HCO3– in an excess of H2O2 is inferred from Raman and 13C n.m.r. spectroscopy; similar evidence is presented for the presence of CO42– in solutions prepared by dissolving solid peroxocarbonates (NaHCO4·H2O and K2C2O6) in aqueous alkali.

On the existence of peroxocarbonates in aqueous solution

Salts of the new catecholato(2–)(cat) complexes [Ru(cat)3]3–, [Ir(cat)3]2–, [Re(cat)3]2–, [WO2(cat)2]2– and [W2O5(cat)2]2– are reported, a number of oxomolybdenum catecholato complexes reinvestigated and some reformulated. Infrared, Raman, and n.m.r. data are reported for the complexes.

Catecholato complexes of ruthenium, iridium, rhenium, molybdenum, and tungsten

Tropolonato complexes of osmium, iridium, platinum, molybdenum and tungsten, and the X-ray crystal structure of MoO2trop2

New complexes of the form trans-[OsO2L2]2– and UO2L·nH2O [H2L = adrenaline (H2ad), noradrenaline (H2nad), dopamine (H2dpm), dopa (H2dp), and isoproterenol (H2prot)] are reported, as are cis-[MO2L2]2–(L = nad, dp, prot for M = Mo or W, and ad for M = W), [MO2(Hdpm)2](M = Mo or W), and [Mo2O5(Had)2]. The structures of these species are discussed on the basis of their Raman, infrared, 1H, and 13C n.m.r. spectra.

William P. Griffith

Papers

Oxo complexes of ruthenium(VI) and (VII) as organic oxidants

On the existence of peroxocarbonates in aqueous solution

Catecholato complexes of ruthenium, iridium, rhenium, molybdenum, and tungsten

Tropolonato complexes of osmium, iridium, platinum, molybdenum and tungsten, and the X-ray crystal structure of MoO2trop2

Complexes of osmium, uranium, molybdenum, and tungsten with the catechol amines adrenaline, noradrenaline, dopamine, dopa, and isoproterenol