AsF5 Research Articles

Fluoride-Ion Donor Properties of AsF5

Fluoride-Ion Donor Properties of AsF₅

Structure and Properties of Fumaryl Fluoride

The molecular structure and the conformational composition of fumaryl fluoride were determined by low‐temperature vibrational spectroscopy and single‐crystal X‐ray structure analysis. Three planar rotational isomers, trans‐trans‐, cis‐cis‐ and cis‐trans‐fumaryl fluoride were identified. C4H2F2O2 crystallizes in the monoclinic space group P21/c with four formula units per unit cell. Besides, Lewis acid‐base adducts between fumaryl fluoride and arsenic pentafluoride were synthesized. These adducts, which contain O–As bonding interactions, were found to crystallize as the monoadducts trans‐cis‐C4H2F2O2·AsF5 and cis‐trans‐C4H2F2O2·AsF5. Moreover, the diadduct trans‐trans‐C4H2F2O2·2 AsF5 was determined by X‐ray crystallography. The experimental data are discussed together with quantum chemical calculations of trans‐trans‐, cis‐cis‐, and cis‐trans‐fumaryl fluoride.

Temperature-Dependent Circuit Modeling and Performance Evaluation Due to Crosstalk in Capacitively Coupled Interconnects of Intercalation-Doped Multilayer Graphene Nanoribbon

The present work explores the temperature-dependent performance evaluation due to crosstalk in coupled interconnects of intercalation-doped multilayer graphene nanoribbons (ID-MLGNR). A temperature-dependent equivalent single conductor (ESC) model of arsenic pentafluoride (AsF5) ID-MLGNR is considered and is employed to analyze its crosstalk performance (i.e., crosstalk-induced noise and crosstalk-induced delay). Other metallic interconnect materials viz. mixed carbon nanotube bundles (MCB) and copper (Cu) are also analyzed in a similar manner. The temperature-dependent crosstalk performance of ID-MLGNR is compared with that of MCB and Cu, at different temperatures from 300 to 500 K. For the specified temperature range, in case of crosstalk-induced noise, the AsF5 ID-MLGNR-based long interconnects demonstrate superior performance to its MCBs and Cu counterparts. Moreover, the temperature-dependent crosstalk-induced delay is less with ID-MLGNR in comparison with both MCB and Cu interconnects. The large values of the mean free path (MFP) and conductivity of AsF5 ID-MLGNR contribute to its improved performance. In addition, the impact of variation in MFP, interlayer spacing and Fermi level is studied on the crosstalk delay performance of ID-MLGNR. From the obtained results, it is revealed that variation in these parameters results in the significant variation of 62 ps, 51 ps and 169 ps, respectively, in the odd mode (OM) crosstalk delay. Hence, for emerging nano-technology nodes (e.g., 14 nm), ID-MLGNR interconnects with its improved crosstalk performance are proposed as a potential alternative to its MCBs and Cu counterparts.

RF analysis of intercalated graphene nanoribbon-based global-level interconnects

Intercalation doping is emerging as a prospective solution to enhance the performance of graphene nanoribbon interconnects. In this paper, the radio frequency (RF) analysis of stage-2 arsenic pentafluoride- and lithium-doped multilayer graphene nanoribbons (MLGNRs) has been carried out for global-level interconnects in terms of skin depth, surface impedance, critical ratio (CR), transfer gain, and 3-dB bandwidth. The skin-depth results demonstrate that doped MLGNRs exhibit minimum performance degradation primarily due to their higher conductivity, mean free path, and momentum relaxation time as compared to neutral MLGNR. An equivalent second-order accurate RLC model of an intercalation-doped MLGNR has been used to extract the transfer gain and 3-dB bandwidth results at 14-nm technology node for global-level interconnects. The results are further evaluated by implementing an advanced π-type equivalent single conductor derived from multi-conductor transmission line model. The doped MLGNR interconnects demonstrate 11-fold enhancement of 3-dB bandwidth as compared to copper (Cu). Also, the delay and energy-delay-product (EDP) computations in time domain for doped MLGNR interconnects exhibit nearly 10 times lesser delay and significant reduction in EDP than Cu counterparts. It is also observed that optimum values for 3-dB bandwidth and EDP parameters for intercalated MLGNRs could be achieved through width optimization. The RF and transient results validate intercalated MLGNRs as a potential candidate to replace Cu for next-generation global-level interconnects.

Arsenic pentafluoride surface adsorption studies on Kagome-phosphorene – a DFT outlook

Arsenic pentafluoride (AsF5) is a highly toxic gas molecule that finds its application in the manufacturing of electro-conductive polymers. Besides, exposure to AsF5 molecule may invite several health issues, for instance, central-nervous-system disorders. Thus, the detection of AsF5 gas is a significant and important concern for public health. For the very first time, we built a novel Kagome phosphorene nanosheet (Kagome-PNS) to study the adsorption behavior of AsF5 molecule on the Kagome-PNS surface using density-functional theory method. The Kagome-PNS owns semiconductor property with an energy gap value of 1.22 eV. Initially, the geometrical stability of Kagome-PNS was verified with the negative value of cohesive formation energy. The transport properties of Kagome-PNS have also been carried out using current-voltage characteristics. Moreover, AsF5 gas molecules are physisorbed on Kagome-PNS, the adsorption energy of the preferential complex structures is found to be −0.099 to −0.377 eV. An innovative finding of the present study acclaims that Kagome-PNS can be proficiently used as a chemical sensor to detect AsF5 gas molecules.

Modeling and Analysis of Electro-Thermal Impact of Crosstalk Induced Gate Oxide Reliability in Pristine and Intercalation Doped MLGNR Interconnects

This work presents the electro-thermal analysis of crosstalk effects in pristine (undoped) and intercalation doped multilayer graphene nanoribbon interconnects (MLGNRs). A temperature dependent distributed $T-$ network model of MLGNR interconnects has been developed for analyzing the crosstalk induced effects. Further, a temperature-aware gate oxide reliability model has been proposed to compute the crosstalk induced overshoot/undershoot impact on ultra-thin gate oxide for CMOS devices in terms of failure-in-time (FIT) for side-contact (SC) pristine as well as top-contact (TC) Arsenic pentafluoride ( $AsF_{5}$ ), Ferric chloride ( $FeCl_{3}$ ) and Lithium ( $Li$ ) intercalation doped and undoped MLGNR interconnects. Subsequently, comparisons with $Cu$ -based interconnects are made over a range of chip operating temperature from 233K to 450K.

Lewis adduct formation of hydrogen cyanide and nitriles with arsenic and antimony pentafluoride.

The reactions of hydrogen cyanide, butyronitrile, cyclopropanecarbonitrile, pivalonitrile and benzonitrile with arsenic pentafluoride and antimony pentafluoride result in the formation of 1 : 1 Lewis adducts, while malononitrile yielded both 1 : 1 and 1 : 2 Lewis adducts. All adducts were isolated and characterized by multinuclear NMR and vibrational spectroscopy, and in most cases by their X-ray crystal structures.

Electro-thermal RF modeling and performance analysis of graphene nanoribbon interconnects

This paper presents an electro-thermal radio frequency (RF) model and performance analysis for multilayer graphene nanoribbon (MLGNR) interconnects. The number of conduction channels is calculated as a function of temperature and Fermi energy. A comprehensive model is developed to calculate the temperature dependent effective mean free path (MFP) considering different scattering mechanisms. The RF model of doped and undoped metallic top-contact (TC), as well as side-contact (SC) MLGNR interconnects is demonstrated using ABCD parameter based multi-conductor transmission line formalism. The RF performance of arsenic pentafluoride ( $$\text {AsF}_5$$ ), lithium (Li) and ferric chloride ( $$\text {FeCl}_3$$ ) intercalation doped TC-MLGNR interconnects is investigated and compared with pristine (undoped) TC and SC-MLGNR interconnects for different temperatures. For the first time, our investigation shows that the electro-thermal RF performance of TC-MLGNR can be improved by intercalation doping. It is found that $$\text {AsF}_5$$ , Li and $$\text {FeCl}_3$$ intercalated top-contact MLGNR can operate up to a few GHz for semi-global interconnects ( $$100\,\upmu $$ m) and several MHz for global interconnects ( $$500\,\upmu $$ m). Our analysis also proves that the Li intercalated TC-MLGNR shows the best RF performance as compared to conventional copper, pristine, and other type of intercalation doped TC-MLGNR interconnects over the chip operating temperature range from 233 to 378 K. The performance of Li intercalated TC-MLGNR has been found to be improved further by increasing the specularity during fabrication.

Electron diffraction analysis for the molecules with degenerate large amplitude motions: Intramolecular dynamics in arsenic pentafluoride

There exists a noticeable disagreement in the difference of axial and equatorial bond lengths in D3h symmetry arsenic and phosphorus pentafluorides between the GED data and high level quantum chemical results. In order to resolve this disagreement, a new structural analysis of the original experiment of (Clippard & Bartell, Inorg. Chem., 9 (1970) 805–811) was undertaken on the basis of modern approach incorporating spectroscopic evidence and quantum chemical information and allowing for intramolecular large-amplitude motion. The results of the analysis prove the internal insufficiency of the experimental material in the description of the accurate positions of the peaks on the radial distribution function. Additional experimental investigation of pentahalide molecules, especially at high temperatures, is of interest.

ChemInform Abstract: Preparation of (Perfluoroalkyl)halogeno-1,3-diselenetanes from the Corresponding Selenocarbonyl Fluorides and Reactions with Boron Trichloride or Arsenic Pentafluoride.

ChemInform Abstract: Preparation of (Perfluoroalkyl)halogeno-1,3-diselenetanes from the Corresponding Selenocarbonyl Fluorides and Reactions with Boron Trichloride or Arsenic Pentafluoride.

A Laboratory‐Scale Synthesis of High‐Purity AsF5 by Direct Fluorination of AsF3.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis of Arsenic Pentafluoride by Static Fluorination of As2O3 in a Closed System.

AbstractFor Abstract see ChemInform Abstract in Full Text.

A laboratory-scale synthesis of high-purity AsF 5 by direct fluorination of AsF 3

Arsenic pentafluoride has found extensive use as a fluoride ion acceptor and oxidant in the field of synthetic inorganic fluorine chemistry. A detailed, laboratory-scale synthesis of high-purity, HF-free AsF 5 from AsF 3 and F 2 gas at low temperatures under static conditions is described. The detailed synthesis of HF-free AsF 3 is also described.

A detailed account of a convenient lab-scale preparation of AsF 5 via direct fluorination of AsF 3

A short summary is given of different preparative routes to the important fluorinating and oxidizing agent arsenic pentafluoride (AsF 5). Among the useful preparative routes to AsF 5 the fluorination of AsF 3 has many advantages. The reaction is less exothermic than that starting from arsenic metal and thus safer, the usage of F 2 is minimized (only one equivalent F 2 per produced equivalent AsF 5 is needed), and a separation from by-products is not necessary. Complete preparative details are presented for the synthesis of AsF 5 from AsF 3 and F 2 at high pressure in a Monel reaction vessel and for the synthesis of the precursor AsF 3 from CaF 2, As 2O 3 and H 2SO 4.

Synthesis of arsenic pentafluoride by static fluorination of As 2O 3 in a closed system

As 2O 3 is oxidized to AsF 5 at 250 °C by elemental fluorine. The synthesis that is described represents a convenient approach for the preparation of AsF 5 on a 30–40 g scale, requiring only commercially available As 2O 3 and elemental fluorine.

Estimation of enthalpy data for reactions involving gas phase ions utilizing lattice potential energies: fluoride ion affinities (FIA) and pF- values of mSbF5(l) and mSbF5(g) (m = 1, 2, 3), AsF5(g), AsF5.SO2(c). Standard enthalpies of formation: Delta(f)H degrees (SbmF5m+1)(-),g) (m = 1, 2, 3), Delta(f)H degrees (AsF6(-),g), and Delta(f)H degrees (NF4+,g).

Fluoride ion affinity (FIA) values (and the associated pF(-) values) are difficult to establish experimentally for pentafluorides of arsenic and antimony. Our approach, utilizing estimated lattice potential energies, provides a further opportunity to establish this data for liquid (and gaseous) SbF(5) and gaseous AsF(5) which compliments values obtained using ab initio routes for monomeric gas phase molecules and adds to results based on rigorous methods. A strategy is developed whereby construction of (multiple) Born-Fajans-Haber cycles centered around the (target) FIA reaction of interest yield a plethora of estimates for the enthalpy change of interest. This general approach is illustrated here by specific estimation of some experimentally based FIA values of SbF(5) and AsF(5). FIA values/kJ mol(-1) and pF- values estimated in this paper are FIA(SbF(5),l) approximately equal to -475 (+/-63), pF-(SbF(5),l) = 11.4 (+/-1.5); FIA(SbF(5),g) approximately equal to -506 (+/-63), pF-(SbF(5),g) = 12.4 (+/-1.5); FIA(2SbF(5),l) approximately equal to -609 (+/-63), pF- (2SbF(5),l) = 14.6 (+/-1.5); FIA (2SbF(5),g) approximately equal to -671 (+/-63), pF- (2SbF(5),g) = 16.0 (+/-1.5); FIA (3SbF(5),l) approximately -635 (+/-39), pF(-) (3SbF(5),l) = 15.2 (+/-0.9); FIA(3SbF(5),g) approximately -728 (+/-39), pF(-) (3SbF(5),g) = 17.4 (+/-0.9); FIA(AsF(5),g) approximately equal to -421 (+/-22), pF(-) (AsF(5),g) = 10.1 (+/- 0.5); and FIA (AsF(5).SO(2),s) approximately equal to -390 (+/-22), pF(-) (AsF(5).SO(2),s) = 9.3 (+/-0.5). Related standard enthalpies of formation (in kJ mol(-1)) are also assigned: Delta(f)H degrees (SbF(6)(-),g) approximately equal to -2075 (+/-52); Delta(f)H degrees (Sb(2)F(11)(-),g) approximately equal to -3520 (+/-63); Delta(f)H degrees (Sb(3)F(16)(-),g) approximately equal to -4874 (+/-39); Delta(f)H degrees (NF(4)(+),g) approximately equal to 903 (+/-32); Delta(f)H degrees (AsF(6)(-),g) approximately equal to -1907 (+/-22).

Alkali-metal fluoroarsenates(iii) revisited; the As4F13– anion, the crystal structure of CsAs4F13 and Raman spectra of MAs4F13 (M = Cs, Rb)

Alkali-metal tridecafluorotetraarsenates(III), CsAs4F13 and RbAs4F13 were synthesized by the reaction of CsF and RbF with liquid AsF3 at 353 K.

17 O NMR Estimation of Oxygen–Central Ion Bonding in the Products of Hydrolysis of Niobium, Tantalum, Arsenic, and Antimony Pentafluorides and the Symbatic Behavior of 17 O and 19 F NMR Chemical Shifts

17 O NMR Estimation of Oxygen–Central Ion Bonding in the Products of Hydrolysis of Niobium, Tantalum, Arsenic, and Antimony Pentafluorides and the Symbatic Behavior of 17 O and 19 F NMR Chemical Shifts

Dissolution equilibria of arsenic pentafluoride in anhydrous hydrogen fluoride

Dissolution equilibria of arsenic pentafluoride in anhydrous hydrogen fluoride have been quantitatively examined by measuring the scattering intensity of the Raman spectra of the corresponding species in the solution at ambient conditions. For the superacid formation reaction, 2HF+AsF 5⇄H 2F ++AsF 6 −, K 1 (=[ H 2 F +] [AsF 6 −]/[HF] 2[AsF 5]) has been determined to be ∼2×10 −5 mol −1 kg, and dinucleation reaction of the anion, AsF 6 −+AsF 5⇄As 2F 11 −, K 2 (= [As 2 F 11 −] /[AsF 6 −][AsF 5]) to be ∼8×10 −1 mol −1 kg, respectively.

Acid-base reactions of tungsten and uranium oxide fluorides in anhydrous hydrogen fluoride

The acid-base reactions of tungsten oxide tetrafluoride, WOF 4. and uranium dioxide difluoride, UO 2F 2, have been examined in anhydrous hydrogen fluoride (HF). WOF 4 reacts with silver(I and II) fluorides, AgF and AgF 2, to form complex salts, AgWOF 5, AgW 2O 2F 9 and AgFW 2O 2F 9. AgFW 2O 2F 9, which is also prepared by the reaction of AgW 2O 2F 9 and F 2 in HF, oxidizes elemental xenon to Xe II in HF at room temperature. UO 2F 2 is a weak fluoro base and only forms salts with strong fluoro acids such as arsenic pentafluoride, AsF 5, in HF. The fluoro acidity of UO 2F 2 seems slightly stronger than that of HF, the reaction with AgF giving a 1:1 compound, AgUO 2F 3.