35Cl NQR spectra of pentafluorophenylchloromethanes. The electronic influence of the pentafluorophenyl group

³⁵Cl NQR spectra of pentafluorophenylchloromethanes C₆F₅CH(R)Cl (R = H, CH₃, Cl, COOC₂H₅, C₆F₅) have been studied to obtain information on the electronic influence of the C₆F₅ group. On the basis of the data thus obtained and literature data, the electronic influence of the C₆F₅ group is discussed.     

Study on the Capabilities of One- and Two-Stage Separation Schemes for Producing Highly Enriched Carbon-13 by the Laser Method

The feasibility of obtaining highly enriched (up to 99.5%) carbon-13 by the method of isotopically selective IR multiple-photon dissociation (MPD) of Freon 22 (CF₂HCl) molecules was studied for one- and two-stage schemes of the process in a laboratory apparatus with the intracavity location of a separation reactor. The concentration of ¹³C in the dissociation product C₂F₄ (tetrafluoroethylene) and the MPD yields were measured depending on the frequency and fluence of laser radiation, as well as on the Freon 22 pressure. At the irradiation geometry used, the concentrations of ¹³C up to 88% were obtained in the first stage of enrichment. The second enrichment stage was based on the isotope-selective dissociation of Freon 22 preliminarily enriched with ¹³C (up to 32.6%). After the second stage, the final ¹³C concentration of 99.5 ± 0.5% was attained in the product C₂F₄.     

Mass spectra of the thioethers C6F5SC6H4X

The mass spectra of a number of thioethers of the type p-XC₆H₄SC₆F₅ (X = H, Cl, NO₂, SC₆F₅, CO₂C₂H₅, C₆H₅) have been examined. These spectra have been compared with those of (C₆H₅)₂S and (C₆F₅)₂S. Fragmentation patterns have been deduced from metastable peaks. The spectrum of p-ClC₆H₄SC₆F₅ has been studied in more detail.     

Polynuclear palladium and gold perhalophenyl derivatives with dppm bridges. Crystal and molecular structure of trans-C6F5Au(μ-dppm)Pd(C6F5)2(μ-dppm)AuC6F5 (dppm = Ph2PCH2PPh2)

Reactions of PdRR′(η¹-dppm)₂ (R = R′= C₆F₅ or C₆Cl₅; R = C₆F₅, R′= Cl; dppm = Ph₂PCH₂PPh₂) with the gold derivatives ClAu(tht), C₆F₅Au(tht), (C₆F₅)₃Au(tht) or O₃ClOAuPPh₃ (tht = tetrahydrothiophen) in appropriate ratios yield the bi- or tri-nuclear complexes PdRR′(dppm)₂AuCl, PdRR′(dppm)₂Au(C₆F₅); PdRR′(dppm)₂Au(C₆F₅)₃; PdRR′(dppmAuCl)₂; PdRR′(dppmAuC₆F₅)₂; PdRR′[dppmAu(C₆F₅)₃]₂, [PdRR′(dppm)₂Au]X (X = ClO₄ or BPh₄); [PPh₃Au(dppm)Pd(C₆F₅)₂(dppm)AuCl]ClO₄ or [PPh₃ Au(dppm)Pd(C₆F₅)₂(dppm)Au(C₆F₅)₃]ClO₄. The structure of trans-Pd(C₆F₅)₂[dppmAu(C₆F₅)]₂ has been determined by X-ray diffraction.     

Zur kenntnis von [O2]22+[Ti7F30]2−

[O₂]²⁺₂[Ti₇F₃₀]^2? has been obtained by reaction of TiO₂ with a mixture of fluorine and oxygen (p_F2/O2 ≈ 300–3500 atm., t ≈ 300–450°C) either as colourless powder or in form of colourless, clear needles. From single crystal studies the spacegroup is P$\text{3}$ - C_3i¹ (No. 147) with a = 10.19₂, c = 6.50_o Å, Z = 1. The crystal structure has been refined to R = 0.086 [R_w = 0.058] (748 unique reflexions [F_o > 2σ(F_o)]). From the structure determination [O₂]²⁺₂[Ti₇F₃₀]^2? has isolated columns of partially distorted [TiF₆] octahedra (- column structure) which are connected only quite loosely by (disordered) O₂⁺ cations. ν_O2+ is at 1857 cm^?1, the magnetic moment μ_eff = 2.35 B.M. (295 K) is quite as expected for a ‘spin-only’ case.     

C6F5XeF, a versatile starting material in xenon-carbon chemistry

The molecules Ar_FXeF (Ar_F=C₆F₅, 2,4,6-C₆H₂F₃) with a more polar Xe-F bond than XeF₂ are versatile starting materials for substitution reactions. Fluorine-aryl substitutions with Cd(Ar_F)₂, C₆F₅SiMe₃/[F]⁻, and C₆F₅SiF₃ formed symmetric and/or asymmetric diarylxenon compounds. Applying C₆F₅BF₂, with a higher F⁻-affinity than the corresponding aryltrifluorosilane, in contrast gave the salt [RXe] [Ar_FBF₃]. Using the alkenyl and alkyl compounds CF₂=CFSiMe₃/[F]⁻, CF₃SiMe₃/[F]⁻, and Cd(CF₃)₂ in reactions with C₆F₅XeF, the perfluoroalkenyl or -alkyl transfer reagents were consumed without observing C₆F₅XeCF=CF₂ or C₆F₅XeCF₃ but the formation of Xe(C₆F₅)₂ (dismutation product) and in the latter case C₆F₅CF₃ (coupling product), gave hints of the desired intermediates.     

The 35Cl NQR spectra and structure of pentafluorophenyltetrachlorophosphorane C6F5PCl4

The low temperature structure of C₆F₅PCl₄ was confirmed by ³⁵Cl NQR measurements as ψ-trigonal bipyramidal, with the C₆F₅ group axial. Discrepancies were found with previously reported data, possible causes of these are discussed.     

Reaction of PF5·CH3CN with sulfide

Nitriles react with PF₅ and also with AsF₅, SbF₅ forming 1:1-adducts. Using C₂Cl₃F₃ as a solvent is of advantage for this reaction. PF₅·CH₃CN and [N(C₂H₅)₄]SH give [N(C₂H₅)₄][P₂S₂F₈] with a sulfur double bridge and hexafluorophosphate in acetonitrile [1]. In case of AsF₅·CH₃CN a salt with the anion [AsF₅NHCSCH₃]^? has been isolated [2]. Following products have been confirmed in a reaction mixture of PF₅·CH₃CN and SH^? in acetonitrile by NMR (³¹P and ¹⁹F): [PF₆]^?, [F₅PSPF₅]^2?,

, F₄PSH, F₃PS, HPS₂F₂, [PS₂F₂]^?, [F₅PNC(SH)CH₃]^?, [F₅PNHCSCH₃]^?, [F₅PSH]^?. With a ratio PF₅·CH₃CN: SH^? = 2:1 the S-bridge-complexes are prefered whereas in case of a ratio 1:1 the non-bridged P-complexes are the main products.     

Observation of structure in the quasicontinuum of multiple-photon-excited C2 F5Cl

We report the observation of strong spectral structure in the dissociation yield of C₂ F₅Cl excited by two CO₂ lasers, as a function of the second, non-resonant laser, observed under molecular-beam conditions. This structure is associated with combination bands revealed by matrix-isolation spectroscopy.     

Zur kenntnis von [O2]+[Mn2F9]−

[O₂]⁺[Mn₂F₉]^? has been prepared for the first time by reaction of MnO₂ or MnF_x (x = 2,3,4) with a mixture of fluorine and oxygen (P_F2/O₂ ≈ 300–3500 atm., t ≈ 350–550°C) either as a dark red powder or as ruby red needles or plates. From single crystal studies the space group is C2/c - C⁶_2h (No. 15) with a = 17.55₂, b = 8.37₃, c = 9.10₁ Å, β = 102.3°, Z = B (at ?150°C). The crystal structure has been refined to R = 0.053 (1619 unique reflections). From the structure determination [O₂]+[Mn₂F₉] has ‘mänder’ like bands of double chains of [MnF₆] octahedra, which are stacked up in layers parallel to (100) with O₂⁺-cations (d_0?0 = 1.10₀ Å) located between the layers. ν_O2 is at 1838 cm^?1 and the magnetic moment μ_eff = 5.63 B.M. is as expected for a ‘spin only’ case without spin-spin interaction.     

IR multiple photon excitation of C2H5F and 1,1-C2H4F2 near dissociation threshold: vibrational emissions from parent and product species

The IR multiple photon excitation and dissociation of C₂H₅F and 1,1-C₂H₄F₂ has been studied by monitoring vibrational fluorescence in the region 2000–4000 cm^?1 following excitation with the focused output from a CO₂ TEA laser.     

Cationic palladium(II) complexes involving unprecedented O-coordination of acetylmethylenetriphenylphosphorane

Cationic pentafluorophenyl palladium(II) complexes of the type [Pd(C₆F₅)L₂(APPY)]ClO₄ (L = PPh₃, PBu₃ⁿ; L₂ = bipy and A acetylmethylenetriphenylphosphorane) have been prepared by addition of APPY to the perchlorato complexes [Pd(OClO₃)(C₆F₅)L₂]; the APPY ligand is O-coordinated, which is unprecedented in keto-stabilized ylide complexes of palladium.The neutral complex Pd(C₆F₅)(Cl)(tht)(APPY) has been made by addition of APPY to the binuclear complex Pd₂(μ-Cl)₂(C₆F₅)₂(tht)₂ (tht = tetrahydrothiophene); in which the APPY ligand shows the normal C-coordination.     

Reaction of C60 with KMnF4 : Isolation and characterization of a new isomer of C60F8 and re-evaluation of the structures of C60F7(CF3) and the known isomer of C60F8

The volatile fluorofullerene products of high-temperature reactions of C₆₀ with the ternary manganese(III, IV) fluorides KMnF₄, KMnF₅, A₂MnF₆ (A⁺ = Li⁺, K⁺, Cs⁺), and K₃MnF₆ were monitored as a function of reaction temperature, reaction time, and stoichiometric ratio by in situ Knudsen-cell mass spectrometry. When combined with fluorofullerene product ratios from larger-scale (bulk) screening reactions with the same reagents, an optimized set of conditions was found that yielded the greatest amount of C₆₀F₈ (KMnF₄/C₆₀ mol ratio 28-30, 470 °C, 4-5 h). Two isomers of C₆₀F₈ were purified by HPLC, one of which has not been previously reported. Quantum chemical calculations at the DFT level combined with 1D and 2D ¹⁹F NMR, FTIR, and FT-Raman spectroscopy indicate that the C₆₀F₈ isomer previously reported to be 1,2,3,8,9,12,15,16-C₆₀F₈ is actually 1,2,3,6,9,12,15,18-C₆₀F₈, making it the first high-temperature fluorofullerene with non-contiguous fluorine atoms. The new isomer, which was found to be 1,2,7,8,9,12,13,14-C₆₀F₈, is predicted to be 5.5 kJ mol⁻¹ more stable than 1,2,3,6,9,12,15,18-C₆₀F₈ at the DFT level. In addition, new DFT calculations and spectroscopic data indicate that the compound previously isolated from the high-temperature reaction of C₆₀ and K₂PtF₆ and reported to be 16-CF₃-1,2,3,8,9,12,15-C₆₀F₇ is actually 18-CF₃-1,2,3,6,8,12,15-C₆₀F₇.     

Synthesis and crystal structure determination of yttrium ultraphosphate YP5O14

The crystal structure of monoclinic YP₅O₁₄ (space group C2/c, a=12.919(2) Å, b=12.796(4) Å, c=12.457(2) Å, β=91.30(1)°, Z=8) has been refined from single-crystal X-ray diffraction data. Full-matrix least-squares refinement on F² using 2249 independent reflections for 183 refinable parameters results in a final R value of 0.027 (ωR=0.069). The structure is isotypic with HoP₅O₁₄. This structure is built up from infinite layers of PO₄ tetrahedra linked through isolated YO₈ polyhedra. The three-dimensional cohesion of the framework results from Y-O-P bridges. This crystal structure refinement leads to the calculated X-ray diffraction powder pattern of this monoclinic polymorph, which has been the starting point of a thorough study of the solid-state synthesis of this ultraphosphate. This investigation further leads to a better outstanding of features observed during the synthesis of powdered samples. The thermal behavior of this ultraphosphate has been studied by DTA and TGA analyses. The infrared and Raman spectroscopic characterizations have been carried out on polycrystalline samples. The luminescence properties of the Eu³⁺ ion incorporated in the monoclinic C2/c polymorph of YP₅O₁₄ as local structural probe show that in YP₅O₁₄: 5% Eu³⁺ sample, the Eu³⁺ ions are distributed over the two Y³⁺ crystallographic sites of C₂ symmetry of this structure.     

Tieftemperatur-flüssigphase-fluorierung von (C6F5)2Te: Bildung von (C6F5)2TeF2, (C6F5)2TeF4 und (C6F11)2TeF4 [1]

(C₆F₅)₂Te reacts with elemental fluorine step by step to form the tellurium fluorides (C₆F₅)₂TeF₂, (C₆F₅)₂TeF₄ and (C₆F₁₁)₂TeF₄, which can be isolated in pure states. The intermediates (C₆F_11?2n)₂TeF₄ (n = 1,2) are detected spectroscopically. (C₆F₅)₂TeF₂ is also formed from the reaction of (C₆F₅)₂Te with XeF₂. The preparations, properties and ¹⁹F n.m.r. spectra of these new compounds are discussed, the mass and vibrational spectra are described.     

Reactions of [Pd(C6F5)2(CNR)2] with [PdCl2(NCPh)2]. Insertion of p-MeC6H4NC into Pd-C6F5 bonds

[Pd(C₆F₅)₂(CNR)₂] (R = Cy, Bu^t, p-MeC₆H₄ (p-Tol)) react with [PdCl₂(NCPh)₂] to give [Pd₂(μ-Cl)₂(C₆F₅)₂(CNR)₂]. In refluxing benzene insertion of isocyanide into the C₆F₅Pd bonds occurs only for R = p-Tol, to give a imidoyl bridged polynuclear complex cis-[Pd₂ (μ-Cl)₂[μ-C(C₆F₅) = N(Tol-p)]_2n]. This complex reacts with (a) Tl(acac) to give [Pd₂{μ-C(C₆F₅) = N(Tol-p)}₂(acac)₂]; (b) neutral monodentate ligands to afford dimeric complexes [Pd₂{μ-C(C₆F₅) = N(Tol-p)}₂Cl₂L₂] (L = NMe₃, py, 4-Me-py, SC₄H₈), and (c) isocyanides to give insoluble complexes of the same composition which are thought to be polymeric, [$\text{Pd}$(CNR)Cl{μ-C(C₆F₅) = $\text{N}$(p-Tol)}]_n (R = p-Tol, Me, Bu^t). Thermal decomposition of cis-[Pd₂ (μ-Cl)₂ [μ-C(C₆F₅) = N( p-Tol)]_2n] gives the diazabutadiene species (p-Tol)NC(C₆F₅)C(C₆F₅)N(p-Tol) in high yield.     

C60F14OFPh3, a fluoroxy derivative of C60F15Ph3; evidence for the presence of ‘missing’ fluorine through restricted rotation of a phenyl group

From the reaction of C₆₀F₁₈ with benzene in the presence of SbCl₅ we have isolated a compound of 1252 amu indicated to be C₆₀F₁₄OFPh₃, a fluoroxyfullerene. Temperature-variable ¹H NMR shows that one phenyl group suffers restricted rotation on cooling to 218 K, attributed to the presence of the OF group which, as in the case of the recently characterised C₆₀F₁₇OF, fails to give a signal for this group in the ¹⁹F NMR. We have isolated also, C₆₀F₁₄O₂FPh₃ (1268 amu) a mixture of oxahomo derivatives of C₆₀F₁₄OFPh₃ arising from oxygen insertion into FCCF bonds. Theoretical calculations for C₆₀F₁₄OFPh₃ indicate that the phenyl group nearest to the OF group is twisted out of the plane containing the other two.     

Optisch aktive übergangsmetall-komplexe : XVIII. Über die reaktion von C5H5Co(CO)(C3F7)j mit isonitrilen

In the reaction of C₅H₅Co(CO)(C₃F₇)I with isonitriles in the molár ratio $\text{1}\text{1}$ the brown complexes C₅H₅Co(CNR)(C₃F₇)I are formed. The fluorine atoms of the α-CF₂ groups are diastereotopic because of the asymmetric center at the Co atom. With (—)-α-phenylethylisonitrile a pair of diastereoisomers is obtained which could not be separated.C₅H₅Co(CO)(C₃F₇)I and C₅H₅Co(CNR)(C₃F₇)I react with excess isonitrile with the formation of benzene soluble, yellow salts [C₅H₅Co(CNR)₂(C₃F₇)]⁺I^?, which can be transformed into the corresponding PF^?₆ salts. The new compounds were characterised by C, H, N, Co analyses, molecular weight determinations, IR, ¹H NMR, ¹⁹F NMR, ¹³C NMR, ESCA and mass spectra.     

Crystal and molecular structure of [η5-C5(CH3)5]Co(O2C6H4), a cobalt(o-catecholate) complex

[η⁵-C₅(CH₃)₅]Co(O₂C₆H₄) crystallizes in the orthorhombic space group Pnma with a 12.942(4), b 12.902(4), c 8.543(3) Å, V 1426(1) ų, and Z = 4. Least-squares refinement of 1688 independent observed reflections, F(_obs) ? 2.5σ(F_obs), gives R_F 3.79 and R_wF 3.72%. The cyclopentadienyl ring contains two short (1.412(3) Å) and three longer (〈av〉 1.430(4) Å) CC bond lenghts, consistent with a slight preference for diolefin bonding. The O₂C₆H₄ fragment is best described as a catecholate with a CO bond distance of 1.338(3), and a CoO distance of 1.837(2) Å.     

Theoretical study of polyoxide clusters B20O30, Al20O30, V20O50, Si20O30H20, and Si20O30F20

The structural, electronic, and vibrational characteristics and energies of the isolated polyoxide clusters B₂₀O₃₀, Al₂₀O₃₀, V₂₀O₅₀, Si₂₀O₃₀H₂₀, and Si₂₀O₃₀F₂₀ and their complexes with the H⁻ ion and ammonia complexes Al₂₀O₃₀ · nNH₃ have been calculated by the density functional theory B3LYP method with different basis sets. The computation results show that the symmetric closo structure I _h with oxygen bridges located above the centers of the faces of an empty [M₂₀] dodecahedron is more favorable for V₂₀O₅₀, Si₂₀O₃₀H₂₀, and Si₂₀O₃₀F₂₀. For B₂₀O₃₀, the cage closo isomer is also more favorable than the other isomers, but its structure is severely distorted as compared to a dodecahedron and has a symmetry close to C ₃ . For Al₂₀O₃₀, the I _h structure corresponds to a high-lying local minimum of the potential energy surface. For Al₂₀O₃₀, a set of unusual puckshaped isomers of symmetry C _i , with different numbers of four-coordinate atoms ^IVAl and three-coordinate atoms ^IIIO, was localized; these structures are more than 90 kcal/mol more favorable than the dodecahedron I _h . The most favorable isomer of Al₂₀O₃₀ contains twelve four-coordinate atoms ^IVAl and four five-coordinate atoms ^VAl. The energies of dissociation of the most favorable M₂₀O₃₀ clusters into the M₂O₃ (C _2v ) and M₄O₆ (T _d ) fragments and, in the case of Al₂₀O₃₀, also into the Al₈O₁₂ (O _h ) and Al₁₂O₁₈ (D _3d ) fragments, have been estimated. The conclusion has been drawn that these clusters can, in principle, exist and can be experimentally detected in the isolated state. Analogous calculations have been performed for ammonia complexes Al₂₀O₃₀ · nNH₃ with n varying from 1 to 20. The effect of solvation on the relative stability of the dodecahedral and puckshaped isomers of the Al₂₀O₃₀ cluster is observed. The isomers with ammonia molecules in their first coordination sphere become much closer to one another on the energy scale; however, the dodecahedron remains a considerably less favorable intermediate. Original Russian Text ? O.P. Charkin, N.M. Klimenko, D.O. Charkin, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 4, pp. 624–635.