Tribromohydroxyphosphonium hexafluorometalate: synthesis, spectroscopic characterization, and crystal structure of Br(3)POH(+)AsF(6)(-)

The reaction of tribromophosphine oxide in the superacidic systems XF/MF(5) (X = H, D; M = As, Sb) leads to tribromohydroxyphosphonium hexafluorometalates. The structure was successfully elucidated in the case of tribromohydroxyphosphonium hexafluoroarsenate. Br(3)POH(+)AsF(6)(-) crystallizes in the orthorhombic space group Pnma (No. 53 with a = 1292.5(1) pm, b = 871.6(1) pm, and c = 845.0(1) pm) with four formula units per cell. The Raman, IR, (1)H NMR, and (31)P NMR spectra of Br(3)POX(+)MF(6)(-) (X = H, D; M = As, Sb) are reported.

Preparation and crystal structure of tetraphenylphosphonium triiodotetrabromide [PPh4][I3Br4]

Tetraphenylphosphonium triiodotetrabromide [PPh4][I3Br4] is obtained by the reaction of tetraphenylphosphonium bromide with iodine monobromide. It is the first example of an iodine rich, seven-membered polybromide. [PPh4][I3Br4] crystallizes triclinic in the space group P1 with a = 10.947(1) A, b = 11.945(1) A, c = 12.896(1) A, alpha = 66.80(1) degrees, beta = 77.21(1) degrees, gamma = 85.73(1) degrees, and two formula units per unit cell. The final R indices [I > 4 sigma(I)] are R1 = 0.0362 and wR2 = 0.0944.

Undecafluorodiarsenate Anion: Synthesis and Crystal Structure of (MeS)(2)CSH(+)As(2)F(11)(-)

Dimethyltrithiocarbonate reacts with the superacidic systems HF/MF(5) and DF/MF(5) (M = As, Sb) to form (MeS)(2)CSX(+)MF(6)(-) (X = H, D). With an excess of AsF(5) the reaction leads to (MeS)(2)CSX(+)As(2)F(11)(-) (X = H, D). The latter salt crystallizes in the monoclinic space group P2(1)/c (No. 14 with a = 7.687(1) Å, b = 21.327(6) Å, c = 8.704(1) Å, and beta = 91.99(1) degrees ) with four formula units per cell. The undecafluorodiarsenate anion contains an As-F-As bridge with two As-F bonds significantly longer than the nonbridging bonds and an As-F-As angle of 159.1(6) degrees. The Raman, IR, and (1)H, (75)As, (19)F, and (13)C NMR spectra of (MeS)(2)CSX(+)SbF(6)(-) and (MeS)(2)CSX(+)As(2)F(11)(-) (X = H, D) are reported.

A New Method for Preparation and Crystal Structure of (Trifluoromethyl)iodine Dichloride

(Trifluoromethyl)iodine dichloride (CF(3)ICl(2)) is synthesized by the reaction of (trifluoromethyl)iodine chloride fluoride (CF(3)I(Cl)F) with trimethylchlorosilane ((CH(3))(3)SiCl) at -40 degrees C. By using this route of preparation, in which CF(3)I(Cl)F undergoes a chlorine-fluorine exchange, CF(3)ICl(2) can be obtained in high purity and yield. CF(3)ICl(2) crystallizes in the orthorhombic space group Cmca with a = 6.990(1) Å, b = 7.985(1) Å, c = 21.177(1) Å, and eight formula units per unit cell. The final R indices [I > 2sigma(I)] are R(1) = 0.0341 and wR(2) = 0.0631. CF(3)ICl(2) is, in contrast to iodine trichloride (ICl(3)), monomeric, and its molecular structure is T-shaped with the CF(3) group in the equatorial position. The Raman, IR, and NMR spectra are also described.

Halogenated Carboxonium Salts: Preparation and Structural Analysis

We have studied the preparation and isolation of the halogenated alkylidene oxonium salts CH(3)OCHX(+)MF(6)(-) (X = Cl, F; M = As, Sb). Addition of dichloromethylmethylether at -78 degrees C to the superacidic media HF/MF(5) resulted in the formation of the chlorine compounds CH(3)OCHCl(+)MF(6)(-), whereas at -65 degrees C the fluorinated salts CH(3)OCHF(+)MF(6)(-) are formed by a chlorine/fluorine exchange. The salts are characterized by their low-temperature IR and Raman spectra. Additionally, the crystal structures of the hexafluoroantimonates are presented. The structures of the cations turned out to be different in some points. The salt CH(3)OCHF(+)SbF(6)(-) crystallizes in the monoclinic space group P2(1)/c with 4 molecules in the unit cell and a = 9.942(2), b = 7.454(2), and c = 10.297(3) Å; beta = 111.27(2) degrees. The salt CH(3)OCHCl(+)SbF(6)(-) crystallizes in the monoclinic space group P2(1)/c with 4 formula in the unit cell and a = 5.970(3), b = 12.019(5), and c = 10.994(5) Å; beta = 92.59(3) degrees.