Homopolyatomic and heteropolyatomic halogen cations

Abstract

This review is not exhaustive in scope but rather focuses on the most recent years of work in the field of cationic halogens, covering the literature up to mid 1992. This area is still currently developing. The review summarizes structure, preparation, and reactivity of cationic halogens. Modem theoretical aspects (ab initio MO calculations) as well as the energetics (thermodynamics) of these species are also included. In particular, the symmetric and unsymmetric structures of heteropolyatomic cations, the charge delocalization and band lengths alternation in npm-npm species (n < 2), and the dimerization by =*-me interactions are discussed.

Cs[Cl3F10]: A Propeller‐Shaped [Cl3F10]− Anion in a Peculiar A[5]B[5] Structure Type

“…Those containing bridging μ‐F atoms are very scarce. Overviews of (homo and hetero) polyhalogen cations and anions have been given in recent review articles . So far, the only known species with μ‐bridging F atoms were reported for Br(III) and I(V).…”

Difluorochloronium(III) Fluoridometallates – from Molecular Building Blocks to (Helical) Chains

“…Difluorochloronium(III) undecafluoridoditantalate(V) crystallizes in the monoclinic space group P12 1 /n1 (No. 14), Pearson code mP64 and Wyckoff sequence 14.e 16 . See Table 2 for selected crystallographic data and details of the structure determination.…”

“…C 2v -symmetric XF 2 + cations and square planar D 4h -symmetric [XF 4 ]anions, see Equation (1) and Equation 2and Scheme 1. [9,10,[12][13][14][15][16][17][18][19][20] (1) (2) Scheme 1. Lewis structures of the ClF 2 + cation and the ClF 4 anion.…”

“…They can form bent, C 2 v ‐symmetric X F 2 + cations and square planar D 4 h ‐symmetric [ X F 4 ] – anions, see Equation (1) and Equation (2) and Scheme 1. [ 9,10,12–20 ] …”

Cs[Cl3F10]: Eine Verbindung mit propellerförmigem [Cl3F10]−‐Anion, die im außergewöhnlichen A[5]B[5]‐Strukturtyp kristallisiert

“…Eine ganze Reihe von ein‐ und mehrkernigen Interhalogenkationen und ‐anionen leiten sich von den Halogenfluoriden ab, wobei solche mit halogenverbrückenden μ‐F‐Atomen sehr selten sind. Der derzeitige Wissensstand zu Homo‐ und Heteropolyhalogenkationen und ‐anionen ist in kürzlich erschienenen Übersichtsartikeln zusammengefasst . Bislang wurden nur Br(III)‐ und I(V)‐haltige Spezies mit μ‐verbrückenden F‐Atomen in Form von Verbindungen isoliert: Sie enthalten die Kationen [Br 2 F 5 ] + und [Br 3 F 8 ] + , sowie die Anionen [Br 2 F 7 ] − , [Br 3 F 10 ] − und [I 3 F 16 ] − .…”