The transition metal hexafluorides

Abstract

The nine transition metal hexafluorides present a unique series of closely related compounds. Deviations from octahedral structures are influenced by Jahn-Teller effects and spin orbit coupling. The most pronounced chemical behaviour is the increasing electron affinity in the direction WF(6)--> PtF(6) and MoF(6)--> RuF(6), so that with PtF(6) and RuF(6) values of 7 eV or higher are reached. All hexafluorides can be used as one electron oxidants, starting with mild (WF(6)) up to extreme (PtF(6), RuF(6)) oxidation power.

Tungsten(VI) and Tungsten(V) Fluoride Complexes

“…[5] Owing to rapid ex-Abstract: WF 6 reacts with phosphines R 3 P forming 1:1 compounds. With R = PA C H T U N G T R E N N U N G (CH 3 ) 3 the coordination around the tungsten atom is capped trigonal prismatic, with R = PA C H T U N G T R E N N U N G (CH 3 ) 2 C 6 H 5 the coordination is capped octahedral, as established by single-crystal structure determinations: 3 ], a stable, green, molecular species, identified among other methods with an crystal structure determination: a = 914.9(1), b = 956.0(1), c = 1449.8 (2) pm, a = 7.642(4), b = 81.648(3), g = 81.5198, space group P1 , Z = 2. Keywords: coordination modes · EPR spectroscopy · fluorides · tungsten · Raman spectroscopy Tables 1 and 2, and Figure 1.…”

“…This is particularly true for the five 5d hexafluorides WF 6 through PtF 6 . [2] These are oxidants with moderate (WF 6 ) up to extreme (PtF 6 ) oxidation power. [3] Each hexafluoride is a stronger oxidant than the previous one.…”

Neutral and cationic tungsten(vi) fluoride complexes with tertiary phosphine and arsine coordination

“…8 Tungsten hexafluoride, which contains tungsten in its highest possible oxidation state, is known to form complexes with a variety of hard Lewis bases, mostly neutral N-donor ligands. [9][10][11][12][13][14][15][16][17] Well-documented examples including [WF 6 (2-F-py)] (capped trigonal prism), 13 [WF 6 (py) 2 ] (bicapped trigonal prism), 14 [WF 6 (2,2 0 -bipy)] (structure unknown) 16 and the [WF 4 (2,2 0 -bipy) 2 ] 2+ cation (distorted dodecahedron). 15,16 On the other hand, reaction of WF 6 with sulfite esters, (RO) 2 SO (R = alkyl), or phosphites, (RO) 3 P, result in OR/F exchange to give, for example, [WF 5 (OR)], 12,18 while reaction of WF 6 with OMe 2 causes O/F exchange, forming [WOF 4 (OMe 2 )].…”

“…Neutral, seven-coordinate W(VI) complexes with trialkylarsines have also been established, whereas triarylarsines and trialkylstibines yield intractable materials. While WF 6 is less oxidising than the other metal hexafluorides, 9 successful incorporation of the soft group 15 donor ligands by taking advantage of the pre-organised o-phenylene backbone may suggest that under suitable reaction conditions coordination chemistry with neutral ligands may also exist for other members of the little studied family of very hard and more highly oxidising transition metal hexafluorides.…”

Octahedral complexes of the series of actinides hexafluorides AnF6

“…According to Molski and Seppelt [3], a total of 16 binary element hexafluorides are known, out of which three are actinide hexafluoride compounds: UF 6 , NpF 6 , PuF 6 . Among the binary hexafluorides, SF 6 and UF 6 are extremely well studied.…”