Hydrogen bonding

Harmon, Kenneth M.; Gennick, Irene.

doi:10.1016/0022-2860(77)87082-8

Cited by 43 publications

(20 citation statements)

References 25 publications

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“…In the previous studies, 7,9 anionic species in EMImF•2.3HF were identified to be ͑HF͒ 2 F Ϫ and ͑HF͒ 3 F Ϫ by IR spectra in comparison with that of the metal salts, M͑HF͒ n F. [15][16][17] Molecular hydrogen fluoride was not detected for the salt of this stoichiometry. In the present study, IR spectroscopy also suggested the absence of free HF in the salt and existence of flat, oligomeric fluorohydrogenate anions such as ͑HF͒ 2 F Ϫ18-21 and ͑HF͒ 3 F Ϫ .…”

Section: Resultsmentioning

confidence: 98%

Physicochemical Properties of 1,3-Dialkylimidazolium Fluorohydrogenate Room-Temperature Molten Salts

Hagiwara¹,

Matsumoto²,

Nakamori³

et al. 2003

J. Electrochem. Soc.

147

154

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Reaction of some N-alkylimidazolium chlorides with anhydrous hydrogen fluoride ͑HF͒ gave nonvolatile room temperature molten salts ͑room temperature ionic liquids͒, RMImF•2.3HF where RMIm ϭ 1,3-dimethylimidazolium ͑DMIm͒, 1-ethyl-3-methylimidazolium ͑EMIm͒, 1-methyl-3-propylimidazolium, 1-butyl-3-methylimidazolium, 1-methyl-3-pentylimidazolium, and 1-hexyl-3-methylimidazolium. Vacuum stable salts at room temperature exhibited similar stoichiometry regardless of the type of cation. In the differential scanning calorimetry ͑DSC͒ curve, DMImF•2.3HF exhibited both the freezing and melting on the cooling and heating process, respectively, while EMImF•2.3HF showed the glass transition on the cooling process and devitrification and melting on the heating process. The other salts show only the glass transition on the DSC curves. High specific conductivities, 110 and 100 mS cm Ϫ1 , were observed at 298 K for DMImF•2.3HF and EMImF•2.3HF, respectively. Introduction of the longer alkyl side chains to the imidazolium cation increased the viscosity and decreased the conductivity. These salts were stable in air and did not etch a Pyrex glass container at ambient conditions. The dissociation pressures of HF from the salts were negligibly small at ambient condition. The electrochemical windows of these salts was about 3 V.Since the discovery of the moisture stable room temperature molten salt ͑RTMS, sometimes called room temperature ionic liquid, RTIL͒, 1-ethyl-3-methylimidazolium tetrafluoroborate in 1992, 1 many RTMS have been reported by the combinations of alkylimidazolium cations and inorganic and organic fluoroanions. 2-8 The number of reports of the alkylimidazolium RTMS containing the remarkably stable bis͓͑trifluoromethyl͒sulfonyl͔ amide anion have been increasing in the last five years. These salts are single salts containing only one kind of cation and anion. The order of conductivity ranges 10 Ϫ1

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Section: Resultsmentioning

confidence: 98%

Physicochemical Properties of 1,3-Dialkylimidazolium Fluorohydrogenate Room-Temperature Molten Salts

Hagiwara¹,

Matsumoto²,

Nakamori³

et al. 2003

J. Electrochem. Soc.

147

154

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“…[6,7]. F-HÁÁÁF [8][9][10][11][12] and N-HÁÁÁN [13][14][15][16] hydrogen bonding is much less investigated, and N-HÁÁÁF hydrogen bondingoutside of modified proteins-is comparatively little (12) 19(1) H(1A) 6c 1,980 (6) 3,350 (7) 768 (14) 31(6) H(1B) 6c 2,840(4) 3,650 (5) 1,488 (14) 30(7) H(1C) 6c 3,660(5) 5,410 (5) 1,018 (14) …”

Section: Resultsmentioning

confidence: 99%

Dissolving the insoluble: CdF2 and moist ammonia form cadmium(II) difluoride monohydrate—synthesis and crystal structure of [Cd(NH3)6]F2·H2O

Kraus

2012

Monatsh Chem

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Hexaamminecadmium(II) fluoride monohydrate (1:1) [Cd(NH 3 ) 6 ]F 2 ÁH 2 O was synthesized from CdF 2 and liquid ammonia in open reaction vessels, so that moisture from the air was in contact with the solvent. The compound crystallizes in the chiral space group P3 1 21-D 4 3 (No. 152) in the form of needle-shaped, colorless crystals with a = 6.8974(1) Å , c = 17.7156(5) Å , V = 729.89(3) Å 3 , and Z = 3.

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“…(FH) n F À anions in other salts have been characterized by several methods such as singlecrystal X-ray diffraction, IR spectroscopy and theoretical calculations [17][18][19][20][21]26,[30][31][32][33][34][35][36][37][38]. Abundance of the anionic species in fluorohydrogenate salts changes depending on the cationic species and HF composition n. EMIm(FH) 2.3 F which has a negligible HF dissociation pressure at room temperature (<10 À2 Torr) contains two anionic species, (FH) 2 F À and (FH) 3 F À , and does not contain detectable amount of free HF molecule [17][18][19].…”

Section: Resultsmentioning

confidence: 99%

“…2, broad absorption bands observed at $500, 1050 and 1800 are definitely assigned to (FH) 2 F À [17][18][19][20][21]26,[33][34][35][36] that is regarded as a main anionic species in this salt. FHF À is known to exhibit a strong absorption band at $1250 cm À1 in IR spectrum, whereas an absorption band of (FH) 3 F À is often unclear but appears at $900 cm À1 [17][18][19][20][21]26,[33][34][35][36]. In the IR spectrum of Cs(FH) 2.3 F, there is no band at 1250 cm À1 and FHF À is concluded not to exist in this system.…”

Section: Resultsmentioning

confidence: 99%

Cesium fluorohydrogenate, Cs(FH)2.3F

Matsumoto

Ohtsuki

Hagiwara

et al. 2006

Journal of Fluorine Chemistry

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Cs(FH) 2.3 F is a liquid salt exhibiting a low viscosity of 20.1 cP and a high conductivity of 86.3 mS cm À1 at 25 8C, in spite of the relatively high melting point (16.9 8C). The high density of 2.82 g cm À3 at the liquid state is due to the heavy atomic weight and small size of cesium atom compared to the organic cations of general ionic liquids. The infrared spectroscopy indicates that this salt contains (FH) 2 F À as a main anionic species. The other anionic species such as (FH) 3 F À found in the cases of other M + (HF) 2.3 F (M = a univalent organic cation) ionic liquid salts is not detected, suggesting its small abundance as well as the presence of neutral HF in the form of molecular and/or oligomers. The result of 1 H NMR also suggests that the anions exchange HF between them. These observations coincide with the experimental result that Cs(FH) 2.3 F acts as an acid against general ionic liquid fluorohydrogenates such as EMIm(FH) 2.3 F (EMIm = 1-ethyl-3-methylimidazolium) to lose HF and give Cs(FH) 2 F precipitate. #

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Hydrogen bonding

Cited by 43 publications

References 25 publications

Physicochemical Properties of 1,3-Dialkylimidazolium Fluorohydrogenate Room-Temperature Molten Salts

Physicochemical Properties of 1,3-Dialkylimidazolium Fluorohydrogenate Room-Temperature Molten Salts

Dissolving the insoluble: CdF2 and moist ammonia form cadmium(II) difluoride monohydrate—synthesis and crystal structure of [Cd(NH3)6]F2·H2O

Cesium fluorohydrogenate, Cs(FH)2.3F

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