Talk:Helium compounds

It was believed

An authoritative reference for this astounding claim must be given. Prior to today, I was unaware that any compounds of He existed, but as a chemist, I am not surprised that at low temperature and/or high pressures they have been observed. Any claim that they do not exist MUST show that the author was considering (in addition to near STP) these extreme conditions. While I certainly wouldn't argue that no one, ever, held such an unscientific belief (that He compounds could not or do not "exist" under any circumstances) I am very dubious that this claim was made by anyone "skilled in the art" and included extremes. The transient nature of ionized He interactions don't, imho, qualify as chemical compounds, the definition has been stretched too far from its original meaning of STABLE or metastable chemical species, here.67.140.181.129 (talk) 15:41, 5 October 2017 (UTC)

The extremes would not have been considered in the past. Work is progressing on what is a "chemical bond", with the bonds to helium just being one end of a continuum with other more traditional bonds. Most of those ionised helium molecules are not transient and are stable by themselves. However the excimers are transient. I would be happy to see you supply references from those people that believed helium could be tricked into compounds by pressure or low temperature in the past. (Ions and excimers have been known for many years but not counted as true compounds as you state). Graeme Bartlett (talk) 12:11, 6 October 2017 (UTC)