Talk:Neon compounds

NeBeO?

If NgBeO is a thing for Ng = He and Ar, why not for Ne? Double sharp (talk) 14:35, 21 November 2016 (UTC)

Note that HeBeO is only in a predicted to exist section. Neon Compounds does not have a predicted section, so even though it is predicted to exist, I did not put it in. Instead here I concentrated on things that have experimental results. Helium has so few real/known molecules/compounds that the article covers predictions and mixtures as well. You are welcome to add a predicted molecules section. Graeme Bartlett (talk) 23:44, 21 November 2016 (UTC)

Another substance known, but not here yet, is a crystalline product with buckminsterfullerine, which is not stable at room temperature, like the argon product is. Neon is outside the bucky balls in that crystal. Information in the same referencesGraeme Bartlett (talk) 23:44, 21 November 2016 (UTC)

Yes, sorry for speaking imprecisely: I'm aware that there is not yet any experimental evidence for real He compounds. I've added a "predicted" section for NeBeO. Also I think we should probably add some of the proposed explanations for why Ne is expected to be even less reactive than He, contrary to the general trend (Wong suggested the larger size of Ne weakening the HNe⁺ ion pair attraction in HNeF, and Frenking et al. suggested repulsive p-π interactions that are for obvious reasons absent for He). Double sharp (talk) 07:57, 5 December 2016 (UTC)

Not van der Waals molecules?

The NeBeS and NeAuF molecules are in the van der Waals molecule section. I am not a physical chemist, but in my mind, van der Waals molecules involve only dispersive interaction between two closed-shell, coordinatively saturated species (e.g., between Ne and CH4 or Ne and Ne). Though fragile, the aforementioned species clearly are the result of interaction between a donor (Ne) and a strongly Lewis acidic, coordinatively unsaturated fragment, with a (dative) covalent bond, however weak it is. In my view, they are more akin to a complex like NeCr(CO)5 than to the van der Waals molecules like helium or neon dimer. Anyone have a suggestion as to how they should actually be classified for the purpose of this article? Alsosaid1987 (talk) 06:59, 13 July 2018 (UTC)

They could probably go in the ligand section. The neon beryllium carbonate molecule is called a "complex" by the reference, and the NeBeS was called a compound by the reference. There is not such a clear cut distinction between the types of bond, as if the two atoms on the bond differ there will be some transfer of charge tomake it more ligand like. Dineon would be completely a van der Waals molecule. Graeme Bartlett (talk) 05:37, 14 July 2018 (UTC)

Note [1] calls NeBeS an anomalously strongly bound van der Waals complex. Graeme Bartlett (talk) 05:48, 14 July 2018 (UTC)

Maybe my understanding of this is not sophisticated enough. I guess the issue is whether there is any covalent contribution to the total bond energy. The computed and measured values for the BDE is around 1 to 4 kcal/mol for these complexes, which is orders of magnitude higher than a "pure" van der Waals molecule like He2 (1.1*10^-5 kcal/mol). Even the very polarizable Xe forms a dimer of only 0.55 kcal/mol binding energy. Thus, it's hard to believe that there is not some covalent contribution. I don't know, it's obviously a semantic question to some extent, but the origin of the binding energy is also of some relevance. Alsosaid1987 (talk) 06:30, 14 July 2018 (UTC)