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Producción Científica, 19F NMR monitoring shows that heating trans-[AuIIIRf2I2]− solutions (Rf = C6F3Cl2-3,5) leads to formation of cis-[AuRf2I2]−, [AuRf3I]− and [AuRfI3]−via kinetic competition between isomerization and Rf/I scrambling. The system evolution is driven by the easy Rf–I reductive elimination from [AuRfI3]− (forming also [AuI2]−), which is faster than any of the Rf–Rf couplings from the coexisting species, hindering the commonly desired and thermodynamically preferred C–C coupling. A kinetic model where I− dissociation triggers both isomerization and transmetalation steps is proposed, which fits well the experimental data. DFT calculations support that the lower bond strength of AuIII–I compared to other halides produces a pathway switch that makes C–I coupling kinetically preferred. Consequently, it is better avoided in reactions looking for C–C coupling.

Mechanistic proposals for the C-H activation reaction enabled by mono-N-protected amino acid ligands (MPAAs) have been supported by DFT calculations. The direct experimental observation of the ligand-assisted C-H activation has...

Analysis of the bonding contributions in molecules [M

Producción Científica, Analysis of the bonding contributions in molecules [MIIICp*(L)XY] (M = Rh, Ir; Cp* = C5Me5; L = CO, CN–, CNR) has uncovered a rich variety of types of interaction that seem to have escaped detection so far, in spite of the continuous popularity of cyclopentadienyl transition-metal complexes since the 1970s. At variance with the M—C≡O bond in square-planar systems, which shows typical metal-to-CO π-back-donation, the nonorthogonal arrangement of the Cp* plane and Rh—C≡O fragment and the pseudooctahedral geometry lead to the observation of many direct lateral donations from other ligands that do not involve the metal orbitals, and we name side donations, for instance, Cp* → π*(CO), Cl → π*(CO), and F → π*(CO). Hybrid donations partially involving the metal, M–Caryl → π*(CO), are also observed. The summation of multiple contributions other than back-donation can easily account for about 20% of the electron donation to the π*(C≡O) orbitals., Junta de Castilla y León (project VA224P20), Ministerio de Economía, Industria y Competitividad (project CTQ2017-89217- P), Ministerio de Ciencia, Innovación y Universidades (project PID2020-118547GB-I00), Irish Research Council (postdoctoral fellowship GOIPD/2020/701)

Producción Científica, Aryl rearrangements triggered by Cl− extraction from trans-[AuIII(Rf)2Cl2]− (Rf = C6F3Cl2-3,5), led quickly to a mixture of [Au(Rf)3(solv)], cis-[Au(Rf)2Cl(solv)] and [Au(Rf)Cl2(solv)] (solv = OEt2, OH2). 19F NMR and X-ray diffraction studies led us to identify the species present in solution and the role of the solvent in their formation, while DFT calculations confirm the thermodynamic basis of their evolution. Very different Rf–Rf coupling rates are found from (μ-Cl)2[cis-Au(Rf)2]2 or cis-[Au(Rf)2ClL] species (L = OEt2, NCMe, Cl−) depending on the coordination strength of the ligand or solvent in the fourth position., Ministerio de Economía, Industria y Competitividad (Projects CTQ2017-89217-Pand CTQ2016-80913-P)