Bond dissociation energies of carbonyl gold complexes: a new descriptor of ligand effects in gold(i) complexes?

Abstract

A new experimental method using mass spectrometry was developed to evaluate ligand electronic effects on gold(i) complexes.

Energetics and Structures of Adducts of JohnPhos(Au+), PPh3(Au+), and IPr(Au+) with Organic Substrates: A Mass Spectrometry and DFT Study

“…Considering the short-term repeatability and the long-term reproducibility (see Supporting Information), the precision is about 1% in NCE units, with experimental NCE50 values covering ranges of 12 to 26 NCE units. For comparison with two analogous studies, uncertainties of 2 to 4 kJ mol -1 for a range of BDEs of 162-186 kJ mol -1 , 26 and of 4-8 kJ mol -1 for a range of 131-175 kJ mol -1 , 28 were reported.…”

“…In ERMS experiments, the role of the size of the dissociating ion, in particular the number of degrees of freedom (DOF) of the dissociating ion, and possibly its mass, was advocated. 28 , 48 , 49 , 50 For this reason, we tested the effect of introducing the DOF, as well as the mass, in the relationships between NCE50 and ΔE, but no improvement was observed (see comments to Figure S6 in Supporting Information).…”

“…To sum up the computational analysis of the energetics of the L(Au + )S adducts, it appears that the DFT approaches used in the literature 26,28 and in this work, and considering the experimental uncertainties, are able to reproduce the experimental gas-phase binding energies with a reasonable precision within series of related adducts, either a single substrate with several L(Au + ) ions, or a series of substrates pertaining to the same functionality coordinated to a few L(Au + ).…”

“…An additional facet of the present work is that the observation of stable Au + adducts in solution, which can reveal reaction intermediates, bring relevant information as regard to the mechanistic aspect of catalysis. 29 In parallel, a quantum chemical study at the density functional theory (DFT) level was carried out for all adducts experimentally investigated, as well as for some adducts of the [PMe3Au] + ion, 26 and for a few L(Au + )CO adducts, 28 for which experimental BDEs data are available. These calculated energetics and structural information on the adducts can be complementary indicators as regard to the activation of the substrates by the Au(I) catalysts.…”

Extended kinetic method and RRKM modeling to reinvestigate proline’s proton affinity and approach the meaning of effective temperature

“…This model is used to describe the fast activation processes that take place via multiple collisions in different API (Atmospheric Pressure Ionization) sources. 13–21 It is also used for multiple collisions taking place in a triple quadrupole collision cell operating under high pressure conditions 22,23 or in the higher energy collisional (HCD) cell of an orbitrap spectrometer. 24 Finally, it is also used to describe the ions produced by laser desorption in different techniques.…”