2 AbstractDetailed experimental and computational studies are reported on the mechanism of the coupling of alkynes with 3-arylpyrazoles at [Rh(MeCN) suggest that the migratory insertion transition state is close in energy to that for C H bond cleavage. In order to model this result correctly, the DFT calculations must employ the full experimental system and include a treatment of dispersion effects. A significantly higher overall barrier to catalysis is computed at {Ru(p-cymene)} for which the rate-limiting process remains CH activation. However, this is now a one-step process corresponding to the  2 - 1 displacement of acetate, and so is still consistent with the lack of a significant experimental isotope effect (k H /k D = 1.1  0.2).3

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Tungsten hexaaryloxide complexes of formula W(OAr) 6 (Ar ) C 6 H 5 , 1; C 6 H 4 F-4, 2; C 6 H 3 F 2 -3,4, 3) have been synthesized by the reaction of W(O)Cl 4 and ArOH in 22-28% yield. The complexes were characterized by 1 H, 13 C, 19 F, and 183 W NMR (1, δ ) -474.8; 2, δ ) -416.3; 3, δ ) -446.3), melting point (1, 95 °C; 2, 101 °C; 3, 105 °C), IR, microanalysis, and singlecrystal X-ray diffraction (octahedral coordination). Aerosol-assisted chemical vapor deposition of W(OAr) 6 using acetone and toluene solvents and substrate temperatures from 300 to 500 °C produced blue tungsten oxide films on glass substrates. The films were analyzed by glancing angle powder diffraction and shown to be amorphous at 300 °C, but consisted of crystalline WO 3-x at higher deposition temperature. Annealing the films from 1 at 550 °C in air for 30 min produced yellow γ-WO 3 with preferred growth in the [020] direction. Raman analysis of the as-formed films showed WO 3-x with evidence for W V -W VI paired ions. Annealed samples produced Raman patterns for γ-WO 3 (807, 715, 273, and 133 cm -1 ). The films were adhesive to the substrate, conformal, passed the Scotch tape test, and gave good coverage. Typical growth rates were 20-50 nm min -1 . SEM showed uniform films consistent with an island growth mechanism. Energy dispersive analysis confirmed the presence of only tungsten and oxygen. XPS showed that the as-formed films were WO 3-x (x ≈ 0.22) with binding energy shifts for W 4f 5/2 at 37.2 and 4f 7/2 34.4 eV and for oxygen 1s at 532.6 eV. The as-formed films had an absorption maxima at 320-360 nm (dependent on film thickness) and an onset for absorption at 400 nm. Reflectance/transmission measurements produced interference fringes that enabled a calculation of film thickness. In general the films showed good transmission from 500 to 1000 nm (60%) and some reflectivity (ca. 20%) over the same region. After annealing, the absorption edge was pushed more into the visible and the films showed evidence for some scattering associated with haze. The blue WO 3-x films showed negligible photocatalytic activity. The annealed, yellow WO 3 films were active photocatalysts and readily destroyed an overlayer of stearic acid.

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Bidentate N,N-pyridylimine or N,N-pyridylamine donors are effective chelating ligands for regiospecific C-H activation at the peri-(C(8))-position of a naphthyl ring on reaction with palladium(ii) acetate; DFT calculations show N,N-chelates bias the cyclopalladation towards 6-membered ring products.

Graphical Contents EntryThe synthesis and structure of chelating amido-NHC and amido-bis(NHC) complexes of Pd and Pt are described, including the first [CNC]Pt complexes and the first Pd arylamido-NHC complex. AbstractWith a view to applications in bifunctional catalysis, a modular cross-coupling strategy has been used to prepare amine bis(imidazolium) salts (3a and 3b) and an amine mono(imidazolium) salt (6) inert Pt analogue 11 was unreactive under the same conditions. Solid-state structures of the complexes 7a, 7b, 9a, 10, 11 and 12 have been determined by single crystal X-ray diffraction.

New methods for peptide modification are in high demand in drug discovery, chemical biology and materials chemistry; methods that modify natural peptides are particularly attractive. A Pd-catalyzed, C-H functionalization protocol for the olefination of phenylalanine residues in peptides is reported, which is compatible with common amino acid protecting groups, and the scope of the styrene reaction partner is broad. Bidentate coordination of the peptide to the catalyst appears crucial for the success of the reaction.