W. B. Fox

Infrared spectroscopic evidence for matrix isolated ``nitrosyl hypofluorite,'' an isomer of nitryl fluoride

The in situ photolysis of molecular fluorine and NO2 molecules in nitrogen matrices at 8°K yields the FN‐bonded nitryl fluoride, FNO2, as the primary reaction product. However, controlled fluorine atom diffusion at 20°K, in the absence of photolytic radiation, results in the formation of the highly reactive, FO‐bonded, nitrosyl hypofluorite, ONOF. Infrared absorptions at 1716.4, 1199.9, 702.3, and 411.9 cm−1 were assigned to this species, which was shown from 15N and 18O isotopic studies to contain two nonequivalent oxygen atoms. The ONOF molecule undergoes intramolecular photorearrangement at wavelengths below 400 nm to produce the more stable FNO2 form.

Infrared spectra and characterization of the products of fluorine atom reactions with matrix isolated NO molecules

Simultaneous matrix deposition of F2 and NO molecules at high dilution in argon and nitrogen onto an 8°K CsI window produces three new infrared absorptions in addition to those of normal, FN‐bonded nitrosyl fluoride, FNO. The infrared features at 1886.6, 734.9, and 492.2 cm−1 (Ar matrix) and their 15N and 18O isotopic counterparts were assigned to the previously unobserved FO‐bonded isomer NOF, which appears to be a bent molecule having a molecular geometry similar to that of nitrosyl fluoride. Controlled fluorine atom diffusion at 20°K, in the absence of photolytic radiation, results in increased yields of the NOF molecule, while matrix photolysis experiments at 8°K have established that this species undergoes intramolecular photorearrangement to the more stable FNO form when exposed to radiation comprised of wavelengths below 280 nm.

Vacuum ultraviolet photolysis of sulfur hexafluoride and its derivatives in argon matrices. The infrared spectrum of the SF5 radical

Vacuum ultraviolet photolysis at 1048, 1067 A of sulfur hexafluoride and its derivatives, SF5X (where X=Cl, Br, and SF5) in dilute argon matrices at 8 K produced two new infrared absorptions at 811.6 and 552.1 cm−1 which were also observed in the argon matrix reactions of fluorine atoms with SF4 molecules. Both features were assigned to the SF5 radical, a new species of C4v symmetry. A weaker absorption at 682.4 cm−1 was tentatively assigned to the SF3 radical, while, in the sulfur–fluorine experiments, secondary reactions produced the known SF−5 anion. The photolytic production of significant yields of SF4 and XF indicated the presence of a simultaneous molecular photoelimination process which, in the case of SF5Br, afforded the direct observation of the BrF fundamental at 650.5 cm−1.

Mono- and dihydryl-pentafluorosulfur-F-alkanes [1]

Abstract The systematic preparation of partially fluorinated pentafluorosulfur alkanes containing no additional halogens is reported. Thus, the indirect addition of “HF” (via KF/formamide) to SF5CH=CF2, SF5CFCF2, and SF5C(CF3)CF2 produces SF5CH(in2)CF3, SF5CHFCF3, and SF5C(CF3)2H respectively. The monohydryl-pentafluorosulfur-F- alkanes react readily with S2O6F2 to form the corresponding fluorosulfates by oxidative displacement of hydrogen, while the dihydryl derivative undergoes cleavage to produce F-acetyl fluoride. Efforts to convert some of the new materials to the important but unknown pentafluorosulfur “ketone,” SF5C(O)CF3, were unsuccessful.

Argon matrix Raman and infrared spectra of SF5Cl, SF5Br, and S2F10

Abstract Infrared and laser-excited Raman spectra of SF 5 Cl, SF 5 Br, and S 2 F 10 have been observed in dilute argon matrices and in the solid phase at 8 K. The first vibrational assignment of the SF 5 Br molecule and assignments for the ν(SCl), ν(SBr), and ν(SS) modes in SF 5 Cl, SF 5 Br, and S 2 F 10 are presented. The chlorine isotopic components of the SCl stretch in SF 5 Cl have been resolved. The Raman spectrum of SF 5 Br, which has not been reported previously, is discussed.

Gas phase and solid state X-ray photoelectron spectra of the substituted acetylenes (SF5)n C2 (CF3)2−n (n = 0, 1, 2): A comparison of the pentafluorosulfur and trifluoromethyl groups

Abstract The core level X-ray photoelectron spectra (XPS) of CF 3 CCCF 3 , CF 3 CCSF 5 and SF 5 CCSF 5 have been measured in the solid state. Gas phase spectra of CF 3 CCCF 3 and CF 3 CCSF 5 have also been obtained. The XPS data, interpreted with the point charge potential model and semiempirical MNDO (minimum neglect of differential overlap) molecular orbital calculations, indicate that the electron withdrawing effect of the −CF 3 group is greater than that of the −SF 5 group. Results further suggest that sulfur 3 d orbitals do not play a detectable role in the bonding or charge distribution in these molecules. Carbon 1 s linewidths of −CF 3 carbon atoms are found to be much narrower than those arising from the acetylenic carbon atoms. The narrower lines correlate with the much higher binding energy of the −CF 3 carbon atoms. Large shifts (nearly 1 eV) in heteroatom core level binding energy differences (for example, F 1 s — C 1 s ) between the gas phase and solid state data are observed. These shifts are attributed to solid state effects (Madelung potential, intermolecular bonding interactions, and/or extramolecular relaxation contributions). From these comparisons it is clear that solid state effects are not uniform in their influence on the photoionized sites in these molecules.

Polyfluoroalkyl chloro- and fluorosulfites

Abstract The first example of polyfluoroalkyl chlorosulfite esters have been prepared in good yield by reaction of the corresponding polyfluoroalcohol-triethylamine adducts with excess SOCl 2 . The polyfluoroalkyl chlorosulfites are easily converted to the fluorosulfite derivatives (∼75%) by reactions with ClF. The polyfluoroalkyl chloro- and fluorosulfites are found to much more thermally stable than their corresponding unfluorinated analogs. The nmr spectra indicate that chemically equivallent groups attached to the α-alkyoxy carbon of these halosulfites are magnetically nonequivallent as a consequence of their asymmetric sulfhur atoms.

Argon matrix infrared spectra of CF3OOF and CF3OOOCF3 and their photolysis products. Spectroscopic evidence for the CF3OO radical

Ultraviolet photolysis of fluoroperoxytrifluoromethane, CF3OOF, in argon matrices at 8 °K produced CF4 and a new species, tentatively identified as the CF3OO radical, with infrared absorptions at 1173.7 and 1094.1 cm−1. This species was also produced, along with CF4, CF3OCF3, and COF2, by photolysis of bistrifluoromethyl trioxide, CF3OOOCF3, at wavelengths below 300 nm. In the latter case, extensive isotopic labeling experiments with CF3 16O16O16OCF3, CF3 16O18O16OCF3, CF3 18O16O18OCF3, and CF3 18O18O18OCF3 led to the observation of four distinct isotopic absorptions for the O–O stretching vibration (1094.1 cm), thus confirming the nonequivalent oxygen atom structure of CF3OO.

Synthesis and reactions of 1-pentafluorosulfur-F-ethylsilver

Abstract Trifluorovinylsulfurpentafluoride, SF5CFCF2, reacted with silver(I) fluoride in acetonitrile solution to form 1-pentafluorosulfur-F-ethylsilver, AgCF(SF5)CF3, which was isolated as the acetonitrile solvate. AgCF(SF5)CF3 reacted with HCl, HBr, H2O, and CH3I to form good yields of HCF(SF5)CF3, with Br2 to form BrCF(SF5)CF3 and (CF3CFSF5)2, and with O2 to produce SOF4 and CF3C(O)F. Thermolysis of AgCF(SF5)CF3·CH3CN resulted in the evolution of CH3CN and formation of (CF3CFSF5)2, C2F5CF(SF5)CF3, SF4, S2F10, CF3CFCFCF3, and Ag. (CF3CFSF5)2 was found to be thermally unstable and decomposed at 100° to S2F10 and CF3CFCFCF3.

Raman spectra of trifluoromethyl hypofluorite and hypochlorite in argon matrices at 8°K

Abstract Laser-excited Raman spectra are reported for CF 3 OF and CF 3 OCl in dilute argon matrices at 8°K as well as for CF 3 OF in the gas phase. Vibrational assignments which differ from those reported by others are presented for the ν(O-F) and ν(O-Cl) stretches in addition to the ν(C-O) vibrations.