Discovering trends in the Lewis acidity of beryllium and magnesium hydrides and fluorides with increasing clusters size
We have reported in the last years the strong effect that Be- and Mg-containingLewis acids have on the intrinsic properties of typical bases, which become acidsupon complexation. In an effort to investigate these changes when the Be and Mgderivatives form clusters of increasing size, we have examine...
| Autores: | , , , , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2024 |
| País: | España |
| Recursos: | Universidad Autónoma de Madrid |
| Repositório: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglês |
| OAI Identifier: | oai:repositorio.uam.es:10486/711747 |
| Acesso em linha: | http://hdl.handle.net/10486/711747 https://dx.doi.org/10.1002/jcc.27356 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Acidity Be Mg Química |
| Resumo: | We have reported in the last years the strong effect that Be- and Mg-containingLewis acids have on the intrinsic properties of typical bases, which become acidsupon complexation. In an effort to investigate these changes when the Be and Mgderivatives form clusters of increasing size, we have examined the behavior of the(MX2)n(M=Be, Mg; X=H, F;n=1, 2, 3) clusters when they interact with ammonia,methanimine, hydrogen cyanide and pyridine, and with their corresponding deproto-nated forms. The complexes obtained at the M06-2X/aug-cc-pVTZ level wereanalyzed using the MBIE energy decomposition formalism, in parallel with QTAIM,ELF, NCIPLOT and AdNDP analyses of their electron density. Forn=1 the interactionenthalpy for the different families of monomers, Be (Mg) hydrides and Be(Mg) fluorides, follows the same trend as the intrinsic basicity of the base that interactswith them. This interaction is greatly reinforced after the deprotonation of the base,resulting in a significant enhancement of the intrinsic acidity of the correspondingMX2–Base complex. For (MX2)2clusters a further reinforcement of the interaction withthe base is observed, this reinforcement being again larger for the deprotonated com-plexes. However, the concomitant increase of their intrinsic acidity is one order ofmagnitude larger for hydrides than for fluorides. Unexpectedly, the cyclic conformers(MX2)3, which are more unstable than the linear ones, become the global minima afterassociation with the base and the same is true for the deprotonated complex. Accord-ingly, a further increase of the intrinsic acidity of the (MX2)3–Base complexes withrespect to the (MX2)2–Base ones is observed. This effect is maximum for (MgF2)3clus-ters, to the point that the (MgF2)3–Base complexes become more acidic than nitricacid, the extreme case being the cluster (MgF2)3–NCH, whose acidity is higher thanthat of perchloric acid |
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