THE HYDROGEN FLUORIDE—ANTIMONY PENTAFLUORIDE SYSTEM^1,2

Abstract

C. (See Discussion.) Solid curves based on ion size parameter 4.3 A. for carbonate and phosphate systems dashed curves based on 6.0 A. Diameter of circles equals 0.008 in pK¡.Konopik and Leberl,18 who reported a value between 11.70 and 11.95 from colorimetric data but with very insecure treatment of activity coefficients. Both references17•18 summarize older data for historical interest.Acknowledgments.-We wish to express our appreciation to the sources listed in Ref. 2 for fellowships supporting the junior author (A.

Predominantly σ‐Bonded Metal Carbonyl Cations (σ‐Carbonyls): New Synthetic, Structural, and Bonding Concepts in Metal Carbonyl Chemistry

“…The use of HFSbF 5 9, 10 again brings advantages: the higher ionizing ability of the protonic superacid and the reduced viscosity of the medium, allow reactions to proceed faster, at lower temperatures and in homogenous phase. It is found, that CO is modestly soluble in superacids, with CO uptake from the gas phase possible at low CO pressures of ∼1 atm 11–13.…”

“…The F atoms of the HF solvate molecules are strongly coordinated in isotridentate and anisobidentate modes to the six C atoms of a regular octahedral [Ir(CO) 6 ] 3+ ion 21. The structure of [Ir(CO) 6 ][SbF 6 ] 3 ⋅ 4 HF21 provides a realistic model for the solvation of superelectrophilic metal carbonyl cations in HFSbF 5 9, 10 and other superacids 4. Additional evidence for the electrophilic nature of the carbonyl C atoms comes from an emerging chemistry48 and the growing use of [M(CO) n ] m + species in catalysis 37…”

“…The replacement of HSO 3 F5 and magic acid, HSO 3 FSbF 5 ,4 first by SbF 5 , the strongest molecular Lewis acid,7, 8 and then by HFSbF 5 ,9, 10 has allowed an extension of the existence range of σ‐metal carbonyl cations and their derivatives 11–13. As seen in Figure 1, there are at present sixteen metals, ranging from Group 6 to 12, that form thermally stable cationic metal carbonyl derivatives.…”

Application of Density Functional Theory Based Car‐Parrinello Simulations to the Study of Catalytic Processes

“…For example, in SbF 5 /HF solutions, Hyman et al [62] and Gillespie and Moss [35] estimated the molar conductivity of the cationic species to 350 W À1 cm 2 mol À1 , which is comparable to the ionic conductivity of H 3 O in water. Moreover, they also found that the electrical conductivity of SbF 5 /HF solutions showed a dramatic dependence on the SbF 5 concentration.…”

On the Quantum Nature of an Excess Proton in Liquid Hydrogen Fluoride

“…[2,[10][11][12] Furthermore, an abnormally high conductivity has been found for dilute SbF 5 /HF solution, [9,13] which has been explained by the Grottus proton jump mechanism. [14] Theoretical investigations based on Car-Parrinello ab initio molecular dynamics (CPMD), [15,16] semiempirical/molecular mechanics methods, [17] empirical valence bond models, [18] and empirical polarizable potential-based molecular dynamics [19] have provided a detailed mechanistic picture of proton solvation and diffusion in systems such water, [20][21][22][23][24][25][26][27][28] ammonia, [29,30] methanol, [31] and liquid hydrogen fluoride.…”