Some aspects of tetramethylammonium fluorochromate (VI) oxidations and identification of the reduced chromium species

Abstract

The reduction product of tetramethylammonium fluorochromate, TMAFC, isolated after oxidation, has been identified from the results of chemical analyses, chemical determination of the oxidation state of chromium, magnetic susceptibility, cyclic voltametry, n.m.r. and i.r. spectral studies as (CH 3 ) 4 N[CrO 2 F], chromium(IV) species. The facile oxidation of triphenylphosphine to triphenylphosphine oxide by TMAFC in acetonitrile provides a clear-cut example of an oxygen transfer reaction.

Synthesis, characterization, X-ray structural analysis and study of oxidative properties of tetraethylammonium chlorochromate

“…The IR spectrum is similar to those of other chlorochromates [16,17]. TEACC is soluble in water, dichloromethane, acetonitrile, methanol, ethanol, propanol, acetone and acetic acid; it is not soluble in benzene, diethyl ether, toluene and cyclohexane.…”

“…The transitions in CrO 3 Cl À are charge transfer [17], with three electronic transitions summarized in table 6.…”

“…An e orbital is strongly -bonding, t 1 is non-bonding, and t 2 is nearly non-bonding. Upon replacement of an oxide by a halide, strong t 2 splitting to orbitals of e and a 1 symmetries is expected, as the e orbital will have halide p character [17][18][19].…”

Chromium Oxide Tetrafluoride and Its Reactions with Xenon Hexafluoride; the [XeF5]+ and [Xe2F11]+ Salts of the [CrVIOF5]−, [CrVOF5]2−, [CrV2O2F8]2−, and [CrIVF6]2− Anions

“…The neutral Cr IV oxide fluoride, CrOF 2 , was synthesized by the thermal decomposition of CrO 2 F 2 at 500 °C, and was found to be insoluble in water, aqueous acids (HCl, HF, HNO 3 ), aqueous bases (NH 4 OH, NaOH, KOH), and common organic solvents. The only Cr IV oxyfluoro‐anion that has been reported is [CrO 2 F] − , which was obtained as a reduction product in the reaction of [(CH 3 ) 4 N ][CrO 3 F] with organic alcohols and was characterized by elemental analysis and IR spectroscopy . To date, there have been no crystal structures reported for [CrOF 5 ] − , [Cr 2 O 2 F 9 ] − , [CrOF 4 ] − , or [CrOF 5 ] 2− .…”

“…The chromium(VI) oxide fluorides, CrO 2 F 2 [1,2] and CrOF 4 , [3][4][5] and salts of the [CrO 3 F] À , [6][7][8] [CrO 2 F 3 ] À , [9] cis-[CrO 2 F 4 ] 2À , [3,10,11] and [CrOF 5 ] À [4,5] anions have been synthesized and characterized. Synthetic and structural studies have shown that CrOF 4 is sufficiently Lewis acidic to form stable adducts with the noble-gas difluorides NgF 2 (Ng = Kr, [5,12] Xe [12] )( vide infra).…”