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The addition of carbon dioxide to ((tBu)PNP)CoH [(tBu)PNP = 2,6-bis(di-tert-butylphosphinomethyl)pyridine] resulted in rapid insertion into the Co-H bond to form the corresponding κ(1)-formate complex, which has been structurally characterized. Treatment of ((tBu)PNP)CoH with PhSiH3 resulted in oxidative addition to form trans-((tBu)PNP)CoH2(SiH2Ph), which undergoes rapid exchange with excess free silane. With 0.5 mol % ((tBu)PNP)CoH, the catalytic hydrosilylation of CO2 with PhSiH3 to a mixture of oligomers containing silyl formate, bis(silyl)acetyl, and silyl ether subunits has been observed.

Generated in situ from air-stable cobalt precursors or readily synthesized using NaHBEt3, (PPh3)3CoH(N2) was found to be an effective catalyst for the hydroboration of alkenes. Unlike previous base-metal catalysts for alkene isomerization-hydroboration which favor the incorporation of boron at terminal positions, (PPh3)3CoH(N2) promotes boron incorporation adjacent to π-systems even in substrates where the alkene is at a remote position, enabling a unique route to 1,1-diboron compounds from α,ω-dienes.

International audienceA Missing Gold Link: An Au(III) alkene complex has been prepared and characterized by NMR spectroscopy and X-ray crystallography. Its bonding features have been analyzed by DFT calculations and natural bond orbital (NBO) analysis. In [(cod)AuMe(2) ](+) , the unequal AuC bond lengths result from the domination of the preference of 1,5-cyclooctadiene (cod) for nonparallel double bonds over back donation from the metal which favors parallel double bonds

Knowledge of exactly how metal complexes react with molecular oxygen is still limited and this has hampered efforts to develop catalysts for oxidation reactions using O2 as the oxidant and/or oxygen-atom source. A better understanding of the reactions of different types of metal complexes with O2 will be of great utility in rational catalyst development. Reactions between molecular oxygen and Pd(0-II) and Pt(0-IV) complexes are reviewed here.

The Pt(IV ) complex (tBuMe 2 nacnac)PtMe 3 (1, tBuMe 2 nacnac=[((4-tBu-2,6-Me 2 C 6 H 2 )NC(CH 3 )) 2 CH]) reacts with molecular oxygen to form a peroxo complex, 2, in which one oxygen atom is bound to the platinum center and the other to the central carbon of the nacnac ligand backbone. Over time, 2 converts to a new Pt(IV) species (3) wherein the oxygen-oxygen bond has been cleaved.

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Crystallographic details for compound 7Crystallographic details for compound 8 Crystallographic details for compound 9 Crystallographic details for compound 10 1 H NMR of compound 2 1 H NMR of compound 5 1 H NMR of compound 9 1 H NMR of compound 10 1 H NMR of compound 12 Crystallographic details for compound 7A yellow prism, measuring 0.19 x 0.15 x 0.10 mm 3 was mounted on a loop with oil. Data was collected at -163 o C on a Bruker APEX II single crystal X-ray diffractometer, Mo-radiation.Crystal-to-detector distance was 40 mm and exposure time was 10 seconds per frame for all sets. The scan width was 0.5°. Data collection was 100% complete to 25° in ϑ. A total of 99922 reflections were collected covering the indices, h = -27 to 27, k = -15 to 15, l = -28 to 27. 3365 reflections were symmetry independent and the R int = 0.0375 indicated that the data was brilliant average (quality 0.07). Indexing and unit cell refinement indicated a C-centered orthorhombic lattice. The space group was found to be C m c a (No.64).