Unravelling highly oxidized nickel centers in the anodic black film formed during the Simons process by X-ray absorption near edge structure spectroscopy.

The Simons process is an electrochemical fluorination method to prepare organofluorine compounds. Despite the wide application, the underlying mechanism is still unclear. We report the investigation of the black film formed on the surface of the anodes in aHF by an Ni K-edge X-ray absorption near edge structure (XANES) investigation.

Trifluoromethyl Fluorosulfonate (CFOSOF) and Trifluoromethoxy Sulfur Pentafluoride (CFOSF) - Two Gaseous Sulfur(VI) Compounds with Insulating Properties.

In this work, we analyzed trifluoromethyl fluorosulfonate (CFOSOF) and trifluoromethoxy sulfur pentafluoride (CFOSF) regarding their potential use as dielectrics by investigating some of their intrinsic and extrinsic properties. Both compounds show a higher breakdown voltage than SF with averaged relative breakdown voltages of 1.3±0.

Reactivity of [AuF (SIMes)]: Pathway to Unprecedented Structural Motifs.

We report on a comprehensive reactivity study starting from [AuF (SIMes)] to synthesize different motifs of monomeric gold(III) fluorides. A plethora of different ligands has been introduced in a mono-substitution yielding trans-[AuF X(SIMes)] including alkynido, cyanido, azido, and a set of perfluoroalkoxido complexes. The latter were better accomplished via use of perfluorinated carbonyl-bearing molecules, which is unprecedented in gold chemistry.

Gold Teflates Revisited: From the Lewis Superacid [Au(OTeF ) ] to the Anion [Au(OTeF ) ].

A new synthetic access to the Lewis acid [Au(OTeF ) ] and the preparation of the related, unprecedented anion [Au(OTeF ) ] with inorganic or organic cations starting from commercially available and easy-to-handle gold chlorides are presented. In this first extensive study of the Lewis acidity of a transition-metal teflate complex by using different experimental and quantum chemical methods, [Au(OTeF ) ] was classified as a Lewis superacid. The solid-state structure of the triphenylphosphine oxide adduct [Au(OPPh )(OTeF ) ] was determined, representing the first structural characterization of an adduct of this highly reactive [Au(OTeF ) ].

Insights on the Lewis Superacid Al(OTeF ) : Solvent Adducts, Characterization and Properties.

Preparation and characterization of the dimeric Lewis superacid [Al(OTeF ) ] and various solvent adducts is presented. The latter range from thermally stable adducts to highly reactive, weakly bound species. DFT calculations on the ligand affinity of these Lewis acids were performed in order to rank their remaining Lewis acidity.

3D-printed equipment to decouple (powder) X-ray diffraction sample preparation and measurement.

An alternative storage method to separate sample preparation from single-crystal and powder X-ray diffraction measurements at home source diffractometers is described. For single crystals, a setup is presented which allows storage of preselected crystals under cryogenic and ambient temperatures. For powders, a disposable sample holder is introduced.

Synthesis of 3--Hypatulin B Featuring a Late-Stage Photo-Oxidation in Flow.

A synthesis of 3--hypatulin B, a highly oxygenated and densely functionalized bicyclic scaffold, is reported. The carbon skeleton was prepared by functionalization of a cyclopentanone and an intramolecular Mukaiyama aldol reaction. Highlights include a late-stage photo-oxidation of a methoxyallene to provide an ester group.

Borane Adducts of Aromatic Phosphorus Heterocycles: Synthesis, Crystallographic Characterization and Reactivity of a Phosphinine-B(C F ) Lewis Pair.

A phosphinine-borane adduct of a Me Si-functionalized phosphinine and the Lewis acid B(C F ) has been synthesized and characterized crystallographically for the first time. The reaction strongly depends on the nature of the substituents in the α-position of the phosphorus heterocycle. In contrast, the reaction of B H with various substituted phosphinines leads to an equilibrium between the starting materials and the phosphinine-borane adducts that is determined by the Lewis basicity of the phosphinine.

Novel synthetic pathway for the production of phosgene.

Chloride ions are efficient catalysts for the synthesis of phosgene from carbon monoxide and elemental chlorine at room temperature and atmospheric pressure. Control experiments rule out a radical mechanism and highlight the role of triethylmethylammonium trichloride, [NEtMe][Cl], as active species. In the catalytic reaction, commercially available [NEtMe]Cl reacts with Cl to form [NEtMe][Cl], enabling the insertion of CO into an activated Cl─Cl bond with a calculated energy barrier of 56.

One-step methylation of aromatic phosphorus heterocycles: synthesis and crystallographic characterization of a 1-methyl-phosphininium salt.

For the first time, the direct synthesis of 1-methyl-phosphininium salts has been achieved by reacting aromatic λ,σ-phosphinines with the readily available dimethyl chloronium salt [(CH)Cl][Al(OTeF)]. The remarkably high electrophilicity of the alkylation reagent in combination with the weakly coordinating pentafluoro-orthotelluratoaluminate anion offers excellent conditions for this one-step approach. Our simple and quantitative access to 1-methyl-phosphininium salts will pave the way to explore the chemistry of such reactive species in more detail.

Structural proof of a [C-F-C] fluoronium cation.

Organic fluoronium ions can be described as positively charged molecules in which the most electronegative and least polarizable element fluorine engages in two partially covalent bonding interactions to two carbon centers. While recent solvolysis experiments and NMR spectroscopic studies on a metastable [C-F-C] fluoronium ion strongly support the divalent fluoronium structure over the alternative rapidly equilibrating classical carbocation, the model system has, to date, eluded crystallographic analysis to confirm this phenomenon in the solid state. Herein, we report the single crystal structure of a symmetrical [C-F-C] fluoronium cation.

Accurate crystal structures and chemical properties from NoSpherA2.

The relationship between the structure and the properties of a drug or material is a key concept of chemistry. Knowledge of the three-dimensional structure is considered to be of such importance that almost every report of a new chemical compound is accompanied by an X-ray crystal structure - at least since the 1970s when diffraction equipment became widely available. Crystallographic software of that time was restricted to very limited computing power, and therefore drastic simplifications had to be made.

Non-classical polyinterhalides of chlorine monofluoride: experimental and theoretical characterization of [F(ClF)].

We present the synthesis and characterization of the first non-classical Cl(i) polyinterhalide [NMe][F(ClF)] as well as the homologous polychloride [NPrMe][Cl]. Both salts were obtained from the reaction of the corresponding ammonium chlorides with ClF or Cl, respectively. Quantum-chemical investigations predict an unexpected planar structure for the [F(ClF)] anion.

Cobalt Corroles as Electrocatalysts for Water Oxidation: Strong Effect of Substituents on Catalytic Activity.

Two Co(III) complexes ( and ) of new corrole ligands (5,15-bis(-methylcarboxyphenyl)-10-(-methylcarboxyphenyl)corrole) and (5,15-bis(-nitrophenyl)-10-(-methylcarboxyphenyl)corrole) with two apical pyridine ligands have been synthesized and thoroughly characterized by cyclic voltammetry, UV-vis-NIR, and EPR spectroscopy, spectroelectrochemistry, single-crystal X-ray diffraction studies, and DFT methods. Complexes and possess much lower oxidation potentials than cobalt(III)--pentafluorophenylcorrole (Co(tpfc)) and similar corroles containing pentafluorophenyl (CF) substituents, thus allowing access to high oxidation states of the former metallocorroles using mild chemical oxidants. The spectroscopic (UV-vis-NIR and EPR) and electronic properties of several oxidation states of these complexes have been determined by a combination of the mentioned methods.

2-(Dimethylamino)phosphinine: A Phosphorus-Containing Aniline Derivative.

The yet unknown 2-amino-substituted λ ,σ -phosphinines are phosphorus-containing aniline derivatives. Calculations show that the strong interaction of the π-donating NR  group with the aromatic system results in a high π-density at the phosphorus atom. We could now synthesize 2-N(CH ) -functionalized phosphinines, starting from a 3-N(CH ) -substituted 2-pyrone and (CH ) Si-C≡P.

Trifluoromethylation of [AuF (SIMes)]: Preparation and Characterization of [Au(CF ) F (SIMes)] (x=1-3) Complexes.

Trifluoromethylation of [AuF (SIMes)] with the Ruppert-Prakash reagent TMSCF in the presence of CsF yields the product series [Au(CF ) F (SIMes)] (x=1-3). The degree of trifluoromethylation is solvent dependent and the ratio of the species can be controlled by varying the stoichiometry of the reaction, as evidenced from the F NMR spectra of the corresponding reaction mixtures. The molecular structures in the solid state of trans-[Au(CF )F (SIMes)] and [Au(CF ) (SIMes)] are presented, together with a selective route for the synthesis of the latter complex.

Synthesis and Characterization of Poly(hydrogen halide) Halogenates (-I).

Herein, we report the synthesis and characterization of a variety of novel poly(hydrogen halide) halogenates (-I). The bifluoride ion, which is known to have the highest hydrogen bond energy of ≈160 kJ mol , is the most famous among many examples of [X(HX) ] anions (X=F, Cl) known in the literature. In contrast, little is known about poly(hydrogen halide) halogenates containing two different halogens, ([X(HY) ] ).

Discoveries and Challenges en Route to Swinhoeisterol A.

In this work, a full account of the authors' synthetic studies is reported that culminated in the first synthesis of 13(14→8),14(8→7)diabeo-steroid swinhoeisterol A as well as the related dankasterones A and B, 13(14→8)abeo-steroids, and periconiastone A, a 13(14→8)abeo-4,14-cyclo-steroid. Experiments are described in detail that provided further insight into the mechanism of the switchable radical framework reconstruction approach. By discussing failed strategies and tactics towards swinhoeisterol A, the successful route that also allowed an access to structurally closely related analogues, such as Δ -24-epi-swinhoeisterol A, is eventually presented.

Friedel-Crafts Type Methylation with Dimethylhalonium Salts.

The dimethylchloronium salt [Me Cl][Al(OTeF ) ] is used to methylate electron-deficient aromatic systems in Friedel-Crafts type reactions as shown by the synthesis of N-methylated cations, such as [MeNC F ] , [MeNC F I] , and [MeN C F ] . To gain a better understanding of such fundamental Friedel-Crafts reactions, the role of the dimethylchloronium cation has been evaluated by quantum-chemical calculations.

Perfluoro Alkyl Hypofluorites and Peroxides Revisited.

A more convenient synthesis of the perfluoro alkyl hypofluorite (F C) COF as well as the hitherto unknown (C F )(F C) COF compound is reported. Both hypofluorites can be prepared by use of the corresponding tertiary alcohols R OH and elemental fluorine in the presence of CsF. An appropriate access to these highly reactive hypofluorites is crucial.

Oxygen-Bridged Ga (Et) (OTeF ) and the Weakly Coordinating Anions [Ga(Et)(OTeF ) ] and [Ga(OTeF ) ].

Salts of the weakly coordinating anions [Ga(OTeF ) ] as well as [Ga(Et)(OTeF ) ] and the neutral Ga (Et) (OTeF ) were synthesized and characterized by spectroscopic methods and single-crystal X-ray diffraction. Ga (Et) (OTeF ) was formed by treating GaEt with pentafluoroorthotelluric acid (HOTeF ) and reacted with PPh Cl and CPh Cl to [PPh ][Ga(Et)(OTeF ) ] and [CPh ][Ga(Et)(OTeF ) ]. In contrast, Ag[Ga(OTeF ) ] was prepared from AgOTeF and GaCl and was used as a versatile starting material for further reactions.

From Polyhalides to Polypseudohalides: Chemistry Based on Cyanogen Bromide.

Pseudohalogens are defined as molecular entities that resemble the halogens in their chemistry. While our understanding of polyhalogen chemistry has increased over the last years, research on polypseudohalogen compounds is lacking. The pseudohalogen BrCN possesses a highly pronounced σ-hole at the bromine side of the molecule, inducing strong halogen bonding.

A Very Strong Methylation Agent: [Me Cl][Al(OTeF ) ].

A new chloronium-containing salt, [Me Cl][Al(OTeF ) ], was synthesized on multigram scale by means of a simple one-pot procedure. The isolated product can be handled at room temperature and used as a strong electrophilic methylation agent. This is demonstrated by the methylation of the very weak bases P(CF ) , PF , MeI, and MeBr.

No Fear of Perfluorinated Peroxides: Syntheses and Solid-State Structures of Surprisingly Inert Perfluoroalkyl Peroxides.

We report on the solid-state structures of bis(nonafluoro-tert-butyl) peroxide [(F C) CO] and bis(undecafluoro-2-methyl-2-butyl) peroxide [(C F )(F C) CO] . These peroxides were prepared from the corresponding hypofluorites and fluorinated silver wool. The solid-state structures obtained after in situ crystallisation show unusual COOC dihedral angles of 180°, as well as elongated O-O bonds because of the bulky perfluorinated alkyl groups.