New Perspectives in the Noble Gas Chemistry Opened by Electrophilic Anions

Stable Noble Gas Compounds Based on Superelectrophilic Anions [B12(BO)11]− and [B12(OBO)11]−

“…Figure 1c-f When a BO ligand in [B 12 (BO) 12 ] 2À or OBO ligand in [B 12 (OBO) 12 ] 2À precursors is removed, positively charged boron atom in B 12 -cage while negatively charged for the whole framework will be generated. The free positively charged boron atom will change the direction of electric field [24] and exhibit high reactivity towards weak nucleophiles, [58] which are the distinctive features of superelectrophilic anion.…”

“…The more stable the dianion is, the more supereletrophilic the generated monoanion is. [24] Such findings lend promising guidance to design other superelectrophilic anions from their stable dianions, in particular those B 12 -cage based ones.…”

“…In recent years, superelectrophilic anions that can covalently bind Ngs were discovered [22][23][24][25] and opened up new opportunities for making Ng-containing compounds. A superelectrophilic anion, negatively charged as a whole but positively charged at the binding site, can bind a Ng atom.…”

“…A superelectrophilic anion, negatively charged as a whole but positively charged at the binding site, can bind a Ng atom. [24] For example, [B 12 Cl 11 ] À can form covalent compounds with Kr and Xe, [22] and superelectrophilic monoanion [B 12 (CN) 11 ] À , generated from the most stable dianion [B 12 (CN) 12 ] 2À reported to date, [26] binding argon via a covalent BÀ Ar bond was observed at room temperature. [23] [B 12 (CN) 11 Ne] À , with a binding energy of 8.9 kJ/ mol, gives the first example of Ne-containing anion within a covalent BÀ Ne bond in an ion trap mass spectrometer with temperature up to 50 K. [25] In the case of [B 12 (CN) 11 He] À , a binding energy of 1.3 kJ/mol may pose a great challenge for its generation in experiment, however, the BÀ He bond has been predicted to show some covalent character.…”

Understanding Periodic and Non-periodic Chemistry in Periodic Tables

“…The unsuccessful attempts in the early twentieth century to prepare noble gas compounds were reviewed by Chernick ( 1963 ) and by Laszlo and Schrobilgen ( 1988 ). The inertness of the noble gases “was preached so dogmatically wherever chemistry was taught that few chemists would spend their time trying to produce impossible compounds.” The trends of valence at the ends of the 2nd vs. the later periods (namely 0 for Ne vs. 8 for Ar, Kr, Xe) are not consistent within the noble-gas group, and later turned out as unreliable (valences under ambient conditions are 0 for He and Ne; 1 and 2 for the border cases Ar and Kr; 6 or 8 for Xe; smaller for Rn; see Lozinšek et al, 2020 ; Rohdenburg et al, 2020 ). Partially correct experimental trials in the late 1920s and predictions by Pauling in the early 1930s were only reproducibly realized in the early 1960s.…”