Alkyl mercury compounds: an assessment of DFT methods

Alkylation of uracil and thymine in the gas phase through interaction with alkylmercury compounds

“…[55] G. Malli also found 2-component DFT to provide bonding and energetics of superheavy roentgenium derivatives, similar to ab initio methods [56]. The method used in our theoretical survey was chosen by taking into consideration a previous assessment of a large set of density functional methods and an ample set of basis sets for the treatment of Hg containing systems [57]. The functionals included in that assessment were three non-hybrid functionals, namely BLYP [58], M06-L [59] and BP86 [60], a GGA functional, B97-D [61], which includes corrections for dispersion; six hybrid functionals, namely M06 [62], B3LYP [63,64], X3LYP [65], PBE0 [66], MPW1PW91 [67] and [68], one long-range corrected functional (LC-BLYP) [69] and a double hybrid (B2PLYP) [70] one.…”

“…Also the following basis sets for Hg, LANL2DZ, MWB60, cc-PVTZ-PP, DEF2-TVZPP, DEF2-TVZPPD, taken from the EMSL basis set library [71,72] were analyzed. In this assessment, [57] it was concluded that B3LYP was the functional which provides the smallest average error, when used in association with a DEF2-TVZPPD basis set for Hg, which includes an effective small core pseudopotential to account for the relativistic effects non-negligible for this element, for the description of the infrared spectra of the compounds investigated, as well as other physicochemical properties, such as ionization energies and binding energies. For this reason, we consider that this DFT approach was proved to provide accurate results when compared to experimental results, although relativistic effects might be relevant in some particular cases.…”

Behavior of Carboxylic Acids upon Complexation with Beryllium Compounds

“…These findings are in contrast with the behavior of squaric acid, which is a 2π e − system, and whose aromaticity increases on going from the free form to the beryllium difluoride complexes. 21 The aforementioned results also indicate that the NICS becomes slightly more negative when H 2 is released, but the difference is so small that aromaticity cannot be considered a driven force in the H 2 loss process. In other words, the induced magnetic field due to the delocalized π e − is not seriously affected by the reaction, as not one but two beryllium bonds are still present in the system, that reinforce a little bit this delocalized current.…”

“…20 We very recently investigated the intrinsic acidity of squaric acid and its chalcogen containing derivatives, its aromaticity and its self-assembly capacity, properties that significantly change when beryllium bonds are present. 21,22 More importantly, our group showed that squaric acid and its derivatives release H 2 when bound to beryllium dihydride. 21 This fact is relevant enough for its potential consequences in hydrogen storage materials to deserve further investigation.…”

“…21,22 More importantly, our group showed that squaric acid and its derivatives release H 2 when bound to beryllium dihydride. 21 This fact is relevant enough for its potential consequences in hydrogen storage materials to deserve further investigation. In particular it would be important to establish if this reaction always takes place (or not) in carboxylic acids complexed with beryllium compounds.…”