Dioxygenyl ion

Radical cations can be generated by many chemical oxidizing reagents, including Brpnsted and Lewis acids, the halogens, peroxide anions or radical anions, metal ions or oxides, nitrosonium and dioxygenyl ions, stable aminium radical cations, semiconductor surfaces, and suitable zeolites. In principle, it is possible to choose a reagent with a one-electron redox potential sufficient for oxidation-reduction, and a two-electron potential insufficient for oxidation-reduction of the radical ion. 

A rich variety of chemical oxidizing reagents have been applied for the generation of radical cations. The principal reagent types include Bronsted and Lewis acids the halogens certain peroxide anions or radical anions numerous metal ions or oxides nitrosonium and dioxygenyl ions stable organic (aminium) radical cations ... 

That platinum hexafluoride is able to oxidise molecular oxygen to form dioxygenyl hexafluoroplatinate(v), has been recently demonstrated by us. The compound has special interest as the first salt in which the dioxygenyl ion, Og, has been observed. Moreover, it is the first hexafiuoroplatinate(v) salt to have been made. Potassium, difluoro-chlorinium (ClFg ), and tetrafluoroiodinium (IF4+) hexafluoroplatinate(v) have been derived from it. 

The structure reveals that the PtFg octahedra, one of which is represented in Fig. 1, are compressed along the three-fold rotation axis along which the dioxygenyl ions lie. 

This trigonal distortion of the MFg ion is similar to that previously observed in the rhombohedral potassium hexafluoro-osmate(v) structured Each ion has twelve fluorine neighbours, six in a puckered ring and almost coplanar with the ion, the other six in sets of three, one above and one below this plane. The situation of the dioxygenyl ion with its long axis coincident with the three-fold rotation axis is more acceptable on the grounds of close packing than the alternative random orientation (equivalent to rotation) of the ion. Apart from the non-spherical nature of the cation, the structure is almost identical with that proposed for the potassium hexafluoroantimonate(v). ... 

As the nitrosyl ion, NO, is similar in size and shape to the dioxygenyl ion, a resemblance of the dioxygenyl hexafluoroplatinate(v) diffraction patterns to those of nitrosyl hexafluoro-osmate(v), -ruthenate(v), and -antimonate(v) is expected. Moreover, since the first ionisation energy of the nitric oxide molecule is 62 kcal. mole lower than that of oxygen, nitrosyl salts are not uncommon. From the unit-cell sizes and molar... 

The O2 molecule can be ionized by PtFg to the dioxygenyl ion, OJ, which exists in 02PtFg, a red crystalline solid formed directly from equimolar quantities of... 

Some species with two oxygen atoms only are the oxygen molecule, O2, the peroxide ion, 02 , the superoxide ion, 02, and the dioxygenyl ion, 02. Draw an MO diagram for each. 

The product contains the 02+ (dioxygenyl) cation, which is close enough to the size of K+ that 02PtF6 and KPtFs are isomorphous. Other compounds are known that contain the 02+ ion, including 02AsF5 and 02BF4, which can be prepared by the reaction... 

Palladium(V) and palladium(III) complexes have also been reported. Two complexes of palladium(V) have been isolated (02)[PdF6] and Na[PdF6]. These were formed by the oxidation of PdF4 in HF with KrF2 in the presence of 02 and NaF respectively.3 The dioxygenyl salt may also be prepared by the reaction of palladium powder with an F2/02 mixture at 320 °C and 60 000 psi. The Raman spectrum of [PdF6] is comparable with other MF6 ions, showing bands for Vi, v2 and v3 at 643, 570 and 268 cm-1. 

One-electron oxidants convert tertiary amines into aminium ions. Chlorine dioxide is an example of such a reagent this converts triethylamine and other tertiary alkylamines into aminium ions, which normally react further by the loss of hydrogen from an a-carbon atom. An example of a synthetic (plication of this reaction sequence is shown in Scheme 24, the inteimediate iminium ion being intercepted intramolecularly." Nitrosonium tetrafluoroborate and dioxygenyl hexafluoroantimonate, 02 SbF6, are also good one-electron oxidants which can be used at low temperature." ... 

The magnetic susceptibility of NO- -[PtFj]" (cub.) has been measured over the temperature range 77—303° k. As in the case of the dioxygenyl salt,i the susceptibility obeys the Curie-Weiss law (6 being NOPtF, 32 0,PtF, 45°). This simple behaviour shows that there are no strong interactions of the molecular magnets and in view of the isomorphism and near isodimensionality of the two salts, the susceptibility of the [PtF,] ion has been taken to be the sttme in both. The molar... 

It is rare that ions of both signs are found. Some of the very few salt-forming hermaphroditic (and so likewise exotic) species include the following [02]+ (e.g., the dioxygenyl salt [02]" [PtF6] and the superoxide... 

Many transition metal complexes form adducts with molecular oxygen. Those that combine reversibly with O2 are designated as oxygen carriers adducts in which O2 is absorbed irreversibly are also known. Here, we shall provide increased-valence descriptions for some reversible Fe(ll) and Co(ll) dioxygenyl addncts, thereby contrasting different formulations for the oxidation state of the metal ion that have been proposed for these types of complexes. 

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