Type 1 Ring-Opening Reactions of Cyclopropanated 7‑Oxabenzonorbornadienes with Organocuprates

For the first time, nucleophilic ring-openings of cyclopropanated 7-oxabenzonorbornadiene were investigated, providing a novel approach to the preparation of 2-methyl-1,2-dihydronaphthalen-1-ols. Satisfactory yields (up to 95%) were achieved using <i>n</i>-Bu₂CuCNLi₂ as the nucleophile and Et₂O as the solvent. The reaction demonstrated successful incorporation of primary, secondary, tertiary and aromatic nucleophiles, as well as ring-openings of substrates bearing arene substituents and C1-bridgehead substituents. A generalized mechanism for these transformations is also proposed

Industrial Coke as an Electrode Material for Environmental Remediation

Industrial coke was evaluated as a low-cost electrode material for environmental remediation, using the dye Orange II as an example substrate. Coke was used as massive pieces in batch cells or in the ground form for use in a packed-bed reactor. The loss of Orange II was faster when the supporting electrolyte contained chloride ion, and under these conditions the reaction involved hypochlorination. In the batch reactor, the current efficiency for mineralization was only modest (4−14%). In the packed-bed reactor, the loss of both starting material and intermediates was fastest at high current and low flow rate, and a near-quantitative current efficiency was achieved. The high current efficiency was explained by the greater surface area of the electrodes in the packed-bed reactor compared with the batch reactor, and better contact between the solution to be remediated and the coke particles. A drawback to the use of coke electrodes for the remediation of aqueous wastes is their tendency to increase the total organic carbon content of an aqueous solution, especially under anodic polarization

Xenon(IV)–Carbon Bond of [C₆F₅XeF₂]⁺; Structural Characterization and Bonding of [C₆F₅XeF₂][BF₄], [C₆F₅XeF₂][BF₄]·2HF, and [C₆F₅XeF₂][BF₄]·<i>n</i>NCCH ₃ (<i>n</i> = 1, 2); and the Fluorinating Properties of [C₆F₅XeF₂][BF₄]

The [C₆F₅XeF₂]⁺ cation is the only example of a Xe^IV–C bond, which had only been previously characterized as its [BF₄]⁻ salt in solution by multi-NMR spectroscopy. The [BF₄]⁻ salt and its new CH₃CN and HF solvates, [C₆F₅XeF₂]­[BF₄]·1.5CH₃CN and [C₆F₅XeF₂]­[BF₄]·2HF, have now been synthesized and fully characterized in the solid state by low-temperature, single-crystal X-ray diffraction and Raman spectroscopy. Crystalline [C₆F₅XeF₂]­[BF₄] and [C₆F₅XeF₂]­[BF₄]·1.5CH₃CN were obtained from CH₃CN/CH₂Cl₂ solvent mixtures, and [C₆F₅XeF₂]­[BF₄]·2HF was obtained from anhydrous HF (aHF), where [C₆F₅XeF₂]­[BF₄]·1.5CH₃CN is comprised of an equimolar mixture of [C₆F₅XeF₂]­[BF₄]·CH₃CN and [C₆F₅XeF₂]­[BF₄]·2CH₃CN. The crystal structures show that the [C₆F₅XeF₂]⁺ cation has two short contacts with the F atoms of [BF₄]⁻ or with the F or N atoms of the solvent molecules, HF and CH₃CN. The low-temperature solid-state Raman spectra of [C₆F₅XeF₂]­[BF₄] and C₆F₅IF₂ were assigned with the aid of quantum-chemical calculations. The bonding in [C₆F₅XeF₂]⁺, C₆F₅IF₂, [C₆F₅XeF₂]­[BF₄], [C₆F₅XeF₂]­[BF₄]·CH₃CN, [C₆F₅XeF₂]­[BF₄]·2CH₃CN, and [C₆F₅XeF₂]­[BF₄]·2HF was assessed with the aid of natural bond orbital analyses and molecular orbital calculations. The ¹²⁹Xe, ¹⁹F, and ¹¹B NMR spectra of [C₆F₅XeF₂]­[BF₄] in aHF are reported and compared with the ¹⁹F NMR spectrum of C₆F₅IF₂, and all previously unreported <i>J</i>(¹²⁹Xe–¹⁹F) and <i>J</i>(¹⁹F–¹⁹F) couplings were determined. The long-term solution stabilities of [C₆F₅XeF₂]­[BF₄] were investigated by ¹⁹F NMR spectroscopy and the oxidative fluorinating properties of [C₆F₅XeF₂]­[BF₄] were demonstrated by studies of its reactivity with K­[C₆F₅BF₃], Pn­(C₆F₅)₃ (Pn = P, As, or Bi), and C₆F₅X (X = Br or I)

Xenon(IV)–Carbon Bond of [C₆F₅XeF₂]⁺; Structural Characterization and Bonding of [C₆F₅XeF₂][BF₄], [C₆F₅XeF₂][BF₄]·2HF, and [C₆F₅XeF₂][BF₄]·<i>n</i>NCCH ₃ (<i>n</i> = 1, 2); and the Fluorinating Properties of [C₆F₅XeF₂][BF₄]

The [C6F5XeF2]+ cation is the only example of a XeIV–C bond, which had only been previously characterized as its [BF4]− salt in solution by multi-NMR spectroscopy. The [BF4]− salt and its new CH3CN and HF solvates, [C6F5XeF2]­[BF4]·1.5CH3CN and [C6F5XeF2]­[BF4]·2HF, have now been synthesized and fully characterized in the solid state by low-temperature, single-crystal X-ray diffraction and Raman spectroscopy. Crystalline [C6F5XeF2]­[BF4] and [C6F5XeF2]­[BF4]·1.5CH3CN were obtained from CH3CN/CH2Cl2 solvent mixtures, and [C6F5XeF2]­[BF4]·2HF was obtained from anhydrous HF (aHF), where [C6F5XeF2]­[BF4]·1.5CH3CN is comprised of an equimolar mixture of [C6F5XeF2]­[BF4]·CH3CN and [C6F5XeF2]­[BF4]·2CH3CN. The crystal structures show that the [C6F5XeF2]+ cation has two short contacts with the F atoms of [BF4]− or with the F or N atoms of the solvent molecules, HF and CH3CN. The low-temperature solid-state Raman spectra of [C6F5XeF2]­[BF4] and C6F5IF2 were assigned with the aid of quantum-chemical calculations. The bonding in [C6F5XeF2]+, C6F5IF2, [C6F5XeF2]­[BF4], [C6F5XeF2]­[BF4]·CH3CN, [C6F5XeF2]­[BF4]·2CH3CN, and [C6F5XeF2]­[BF4]·2HF was assessed with the aid of natural bond orbital analyses and molecular orbital calculations. The 129Xe, 19F, and 11B NMR spectra of [C6F5XeF2]­[BF4] in aHF are reported and compared with the 19F NMR spectrum of C6F5IF2, and all previously unreported J(129Xe–19F) and J(19F–19F) couplings were determined. The long-term solution stabilities of [C6F5XeF2]­[BF4] were investigated by 19F NMR spectroscopy and the oxidative fluorinating properties of [C6F5XeF2]­[BF4] were demonstrated by studies of its reactivity with K­[C6F5BF3], Pn­(C6F5)3 (Pn = P, As, or Bi), and C6F5X (X = Br or I)