SO2 F2 Research Articles

The verification of delta SCF and Slater's transition state theory for the calculation of core ionization energy.

The core ionization energies of second- and third-period elements of the molecules C2 H5 NO2 , SiF4 , Si(CH3 )4 , PF3 , POF3 , PSF3 , CS2 , OCS, SO2 , SO2 F2 , CH3 Cl, CFCl3 , SF5 Cl, and Cl3 PS are calculated by using Hartree-Fock (HF), and Kohn-Sham (KS) with BH&HLYP, B3LYP, and LC-BOP functionals. We used ΔSCF, Slater's transition state (STS), and two previously proposed shifted STS (1) and shifted STS (2) methods, which have been developed. The errors of ΔSCF and STS come mainly from the self-interaction errors (SIE) and can be corrected with a shifting scheme. In this study, we used the shifting parameters determined for each atom. The shifted STS (1) reproduces ΔSCF almost perfectly with mean absolute deviations (MAD) of 0.02 eV. While ΔSCF and STS vary significantly depending on the functional used, the variation of shifted STS (2) is small, and all shifted STS (2) values are close to the observed ones. The deviations of the shifted STS (2) from the experiment are 0.24 eV (BH&HLYP), 0.19 eV (B3LYP), and 0.23 eV (LC-BOP). These results further support the use of shifted STS methods for predicting the core ionization energies.

Ruthenium-Catalyzed Synthesis of Aryl and Alkenyl Halides from Fluorosulfonates.

Aryl and alkenyl halides are widely used as key intermediates in organic synthesis, particularly for the formation of organometallic reagents or as radical precursors. They are also found in pharmaceutical and agrochemical ingredients. In this work, the synthesis of aryl and alkenyl halides from the corresponding fluorosulfonates using commercially available ruthenium catalysts is reported. Notably, this is the first conversion of phenols to aryl halides that is efficient with chloride, bromide, and iodide. Fluorosulfonates are readily prepared using sulfuryl fluoride (SO2 F2 ) and less expensive substitutes for triflates. Although aryl fluorosulfonates and their reactions are well known, this is the first report of an efficient coupling of alkenyl fluorosulfonates. To finish, it was demonstrated, by means of representative examples, that the reaction is possible in a one-pot process, starting directly from phenol or aldehyde.

New Chemical Transformations Involving SO2 F2 -Mediated Alcohol Activation.

Sulfuryl fluoride is a gas produced on a multi-ton scale for its use as a fumigant. In the last decades, it has gained interest in organic synthesis as a reagent with unique properties in terms of stability and reactivity when compared to other sulfur-based reagents. Sulfuryl fluoride has not only been used for sulfur-fluoride exchange (SuFEx) chemistry but also encountered applications in classic organic synthesis as an efficient activator of both alcohols and phenols, forming a triflate surrogate, namely a fluorosulfonate. A long-standing industrial collaboration in our research group drove our work on the sulfuryl fluoride-mediated transformations that will be highlighted below. We will first describe recent works on metal-catalyzed transformations from aryl fluorosulfonates while emphasizing the one-pot processes from phenol derivatives. In a second section, nucleophilic substitution reactions on polyfluoroalkyl alcohols will be discussed and the value of polyfluoroalkyl fluorosulfonates in comparison to alternative triflate and halide reagents will be brought to light.

Traceless N-Polyfluoroalkylation of Weakly Nucleophilic Nitrogen Containing Compounds.

Here we report an efficient access to high-value N-polyfluoroalkyl anilines, primary polyfluoroalkylamines and N,N-bis(polyfluoroalkyl)amines, via N-polyfluoroalkylation of sulfonamides and phthalimide derivatives using sulfuryl fluoride (SO2F2). The in situ formation of polyfluoroalkyl fluorosulfonates from commercially available fluorinated alcohols and economical sulfuryl fluoride is highly advantageous given that some polyfluoroalkyl halides are ozone-depleting substances (ODS) regulated by the Montreal protocol. This general method is applied to the polyfluoroalkylation of a variety of sulfonamides, N-sulfonyl carbamates and phthalimide with a wide tolerance of functional groups. The process thus provides viable access for industry to N-(polyfluoroalkyl)anilines as well as primary and secondary N-(polyfluoroalkyl)amines, which are very valuable but not easily accessible building blocks for life science applications.

P-Doped h-BN Monolayer: A High-Sensitivity SF6 Decomposition Gases Sensor

SF6 decomposition gas monitoring is of great significance to gas-insulated switchgear (GIS) fault detection and early warning and even the safe and stable operation of the power system. As a gas sensing material, the h-BN monolayer shows good application potential in sensing technology. Therefore, this study calculated and analyzed the gas-sensing response characteristics of P-BN monolayers to SF6 decomposition gases (SO2F2 and SOF2) based on the first-principles density functional theory, such as total density of state and sensitivity. In order to prove the selectivity of the P-BN monolayer for SO2 F2 and SOF2 gas molecules, the gas-sensitive adsorption parameters of the P-BN monolayer for H2O and CO2 gas molecules were calculated. The results show that the adsorption of SO2 F2 and SOF2 gas molecules on the P-BN monolayer is relatively strong, which is in the critical state of physical adsorption and chemical adsorption. The adsorption of H2 O and CO2 molecules is relatively weak. P-BN monolayer showed good selectivity and high sensitivity for SO2 F2 and SOF2 gas molecules. This study provides a theoretical basis for the application of P-BN monolayer in the field of SF6 decomposition gas monitoring and provides a novel way and idea for the development of other gas sensors.

Concise and Additive-Free Click Reactions between Amines and CF3 SO3 CF3.

Trifluoromethyl trifluoromethanesulfonate has proved to be an excellent reservoir of difluorophosgene and a promising click ligation for amines in the preparation of urea derivatives, heterocycles, and carbamoyl fluorides under metal- and additive-free conditions. The reactions are rapid, efficient, selective, and versatile, and can be performed in benign solvents, giving products in excellent yields with minimal efforts for purification. The characteristics of the reactions meet the requirements of a click reaction. The use of trifluoromethyl trifluoromethanesulfonate as a click reagent is advantageous over other "CO" sources (e.g., TsOCF3 , PhCO2 CF3 , CsOCF3 , AgOCF3 , and triphosgene) because this reagent is readily accessible; easy to scale up; and highly reactive, even under metal- and additive-free conditions. It is anticipated that CF3 SO3 CF3 will be increasingly as important as SO2 F2 as a click agent in future drug design and development.

Novel Approaches to Access Arylfluorosulfates and Sulfamoyl Fluorides Based on Sulfur (VI) Fluoride Exchange.

Sulfur (VI) fluoride exchange (SuFEx) is a new family of click chemistry reactions that relies on readily available sulfuryl fluoride (SO2 F2 ) and ethenesulfonyl fluoride to build diverse chemical structures bearing the SVI -F motif, such as fluorosulfate (-OSO2 F) and sulfonyl fluoride (-SO2 F). These motifs could be useful functional groups and connective linkers in organic synthesis. This unit describes two protocols for performing SuFEx. The first protocol describes an in situ method for rapid generation of arylfluorosulfates in 96-well plates for high-throughput screening. The second protocol outlines use of a shelf-stable fluorosulfuryl imidazolium salt for generating arylfluorosulfates and sulfamoyl fluorides. © 2019 by John Wiley & Sons, Inc.

A New Portal to SuFEx Click Chemistry: A Stable Fluorosulfuryl Imidazolium Salt Emerging as an “F−SO2+” Donor of Unprecedented Reactivity, Selectivity, and Scope

Sulfuryl fluoride, SO2 F2 , has been found to derivatize phenols in all kinds of environments, even those in highly functional molecules. We now report that a solid fluorosulfuryl imidazolium triflate salt delivers the same "F-SO2 +" fragment to Nu-H acceptor groups in the substrates. However, this triflate salt is a far more reactive fluorosulfurylating agent than SO2 F2 and displays selectivity preferences of its own. Moreover, the new azolium triflate reagent reacts once with primary amines and anilines before the reaction stops. On the other hand, with triethylamine and two equivalents of the "F-SO2 +" donor present, it proceeds on to the bis(fluorosulfuryl)imides in good yield-two important conversions that we have never seen with sulfuryl fluoride as the electrophile.

SO2 F2 -Mediated One-Pot Synthesis of Aryl Carboxylic Acids and Esters from Phenols through a Pd-Catalyzed Insertion of Carbon Monoxide.

A one-pot Pd-catalyzed carbonylation of phenols into their corresponding aryl carboxylic acids and esters through the insertion of carbon monoxide has been developed. This procedure offers a direct synthesis of aryl carboxylic acids and esters from inexpensive and abundant starting materials (phenols, SO2 F2 and CO) under mild conditions. This method tolerates a broad range of functional groups and is also applicable for the modification of complicated natural products.

Multidimensional SuFEx Click Chemistry: Sequential Sulfur(VI) Fluoride Exchange Connections of Diverse Modules Launched From An SOF4 Hub.

Sulfur(VI) fluoride exchange (SuFEx) is a new family of click chemistry based transformations that enable the synthesis of covalently linked modules via SVI hubs. Here we report thionyl tetrafluoride (SOF4 ) as the first multidimensional SuFEx connector. SOF4 sits between the commercially mass-produced gases SF6 and SO2 F2 , and like them, is readily synthesized on scale. Under SuFEx catalysis conditions, SOF4 reliably seeks out primary amino groups [R-NH2 ] and becomes permanently anchored via a tetrahedral iminosulfur(VI) link: R-N=(O=)S(F)2 . The pendant, prochiral difluoride groups R-N=(O=)SF2 , in turn, offer two further SuFExable handles, which can be sequentially exchanged to create 3-dimensional covalent departure vectors from the tetrahedral sulfur(VI) hub.

Development of a suitcase time‐of‐flight mass spectrometer for in situ fault diagnosis of SF6‐insulated switchgear by detection of decomposition products

Sulfur hexafluoride (SF6 ) gas-insulated switchgear (GIS) is an essential piece of electrical equipment in a substation, and the concentration of the SF6 decomposition products are directly relevant to the security and reliability of the substation. The detection of SF6 decomposition products can be used to diagnosis the condition of the GIS. The decomposition products of SO2 , SO2 F2 , and SOF2 were selected as indicators for the diagnosis. A suitcase time-of-flight mass spectrometer (TOFMS) was designed to perform online GIS failure analysis. An RF VUV lamp was used as the photoelectron ion source; the sampling inlet, ion einzel lens, and vacuum system were well designed to improve the performance. The limit of detection (LOD) of SO2 and SO2 F2 within 200s was 1ppm, and the sensitivity was estimated to be at least 10-fold more sensitive than the previous design. The high linearity of SO2 , SO2 F2 in the range of 5-100ppm has excellent linear correlation coefficient R(2) at 0.9951 and 0.9889, respectively. The suitcase TOFMS using orthogonal acceleration and reflecting mass analyzer was developed. It has the size of 663×496×338mm and a weight of 34kg including the battery and consumes only 70W. The suitcase TOFMS was applied to analyze real decomposition products of SF6 inside a GIS and succeeded in finding out the hidden dangers. The suitcase TOFMS has wide application prospects for establishing an early-warning for the failure of the GIS. Copyright © 2016 John Wiley & Sons, Ltd.

ChemInform Abstract: Sulfur(VI) Fluoride Exchange (SuFEx): Another Good Reaction for Click Chemistry

AbstractReview: [147 refs.

Sulfur(VI) fluoride exchange (SuFEx): another good reaction for click chemistry.

Aryl sulfonyl chlorides (e.g. Ts-Cl) are beloved of organic chemists as the most commonly used S(VI) electrophiles, and the parent sulfuryl chloride, O2 S(VI) Cl2 , has also been relied on to create sulfates and sulfamides. However, the desired halide substitution event is often defeated by destruction of the sulfur electrophile because the S(VI) Cl bond is exceedingly sensitive to reductive collapse yielding S(IV) species and Cl(-) . Fortunately, the use of sulfur(VI) fluorides (e.g., R-SO2 -F and SO2 F2 ) leaves only the substitution pathway open. As with most of click chemistry, many essential features of sulfur(VI) fluoride reactivity were discovered long ago in Germany.6a Surprisingly, this extraordinary work faded from view rather abruptly in the mid-20th century. Here we seek to revive it, along with John Hyatt's unnoticed 1979 full paper exposition on CH2 CH-SO2 -F, the most perfect Michael acceptor ever found.98 To this history we add several new observations, including that the otherwise very stable gas SO2 F2 has excellent reactivity under the right circumstances. We also show that proton or silicon centers can activate the exchange of SF bonds for SO bonds to make functional products, and that the sulfate connector is surprisingly stable toward hydrolysis. Applications of this controllable ligation chemistry to small molecules, polymers, and biomolecules are discussed.

Comparison of intermolecular interactions in two phases of MeNSOF2

Abstract MeNSOF2 was crystallised by laser-assisted zone refinement at 150 K. The structure obtained by X-ray diffraction initially on cooling to 140 K was triclinic, P-̄, but this transformed slowly to a second phase, which was monoclinic C2/c. Bond distances and angles are similar to equivalent interactions in (MeN)2 SF2 and SO2 F2. Intermolecular interactions in both phases are dominated by dispersion, though electrostatics are also important in all the most energetic contacts. Though no interatomic contacts fall within the sums of van der Waals radii of the contacting atoms, PIXEL calculations indicate that some intermolecular energies are similar to medium-strength hydrogen bonds. The monoclinic phase is denser than the triclinic phase, having stronger dispersion interactions. PIXEL and DFT calculations indicate that the two phases are energetically very finely balanced, but phase I becomes competitive at higher temperature on account of the entropy advantage of its ‘looser’ structure. DFT phonon energy calculations suggest that the mechanism of the transition may involve coupling between acoustic and low energy optical phonons.