Properties of Tetrahydrofuran

Molecular weight 72.104 g/mole Boiling point (760 mm Hg) 66 °C Freezing point -108.5 °C Specific gravity d 4 0.886 Refractive index no 1.4073 

AHf°(liq) -51.67 kcal/mole = -216,19 kJ/mole AHf (g) -44.02 kcal/mole = -184.18 kJ/mole Flash point (closed cup) -22 °C Ignition temperature 260 °C Limited solubility in water 

Toxicity Tetrahydrofuran rates as one of the least toxic solvents, but it has a narcotic effect similar to that of diethyl ether. It gives rise to skin and mucous membrane irritation. As it dissolves the upper layers of the skin, hand protection should be provided to prevent contact. The occupational exposure limit is 200 ppm. 

Vapor pressures At -70 °C (solid) 0.01 torr At-30°C (solid) 1.0 torr At 0 °C (liquid) 13 torr 

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Xuhui Zhang, Xiaobing Lu, Shuyun Wang, et al. 2011. Experimental study of static and dynamic properties of tetrahydrofuran hydrate-bearing sediments. Rock and Soil Mechanics, 32(l) 303-308. 

The physical properties of finish removers vary considerably due to the diverse uses and requirements of the removers. Finish removers can be grouped by the principal ingredient of the formula, method of appHcation, method of removal, chemical base, viscosity, or hazardous classification. Except for method of apphcation, a paint remover formulation usually has one aspect of each group, by which it can be used for one or more appHcations. A Hst of the most common organic solvents used in finish removers has been compiled (3). Many are mentioned throughout this article others include ethyl lactate [97-64-3] propylene carbonate [108-32-7] furfural alcohol [98-01-1/, dimethyl formamide [68-12-2] tetrahydrofuran [109-99-9] methyl amyl ketone [110-43-0] dipropylene glycol methyl ether [34590-94-8] and Exxate 600, a trade name of Exxon Chemicals. 

Pyrrohdine [123-75-1] (tetrahydropyrrole) (19) is a water-soluble strong base with the usual properties of a secondary amine. An important synthesis of pyrrohdines is the reaction of reduced furans with excess amine or ammonia over an alumina catalyst in the vapor phase at 400°C. However, if labde substituents are present on the tetrahydrofurans, pyrroles may form (30). 

Application of the reaction to the 2-azidobenzoyl derivative of diethylene glycol monomethyl ether 92, in a mixture of tetrahydrofuran and diethylene glycol monomethyl ether as the nucleophile, affords 2-(2-methoxyethoxy)ethyl 2-[2-(2-methoxyethoxy)ethoxy]-37/-azepine-3-carbo-xylate (93), which displays metal cation complexing properties towards lithium, potassium, and. to a lesser extent, barium and calcium cations.198... 

Methylmagnesium chloride has been added to various d-(4-substituted-phenyl) <5-oxo esters 15 (X = H, Cl 13, F, Cl, Br, OC11,) which provides the diastereomeric -lactones 1642. The electronic properties of the phenyl 4-substituent have no significant influence on the diastereoselectivity. Except for the 4-methoxyphenyl compound, which is unreactive even at 60 °C, a ratio of ca. 40 60 in favor of the anti-Cram product is observed at 60 "C in tetrahydrofuran as reaction solvent. Lowering the reaction temperature to 0 °C slightly increases the anti-Cram selectivity in the case of the 4-fluoro-, 4-chloro-, and 4-bromo-substituted compounds. On the other hand, a complete loss of reactivity is observed with the <5-phenyl- and <5-(4-methylphenyl)-substituted h-oxo esters. 

The spectral properties of pentafluorophenylcopper te-tramer are as follows infrared (Nujol) cm. 1630 medium 1391 medium 1353 medium 1275 medium 1090,1081, and 1071 strong triplet 978 strong 785 medium fluorine magnetic resonance (tetrahydrofuran with trichlorofluoromethane as internal reference) 8 (multiplicity, number of fluorines, assignment, coupling constant J in Hz.) 107.2 (20-line multiple , 2, ortho F), 153.4 (triplet of triplets, 1, para F, J= 1.3 and 20), 162.3 (17-line multiplet, 2, meta F). Absorptions at 820-900, 1100-1125, and 1290 cm.- in the infrared spectrum and at 8 3.05 in the proton magnetic resonance spectrum indicate that dioxane is still present. 

The PGS obtained by Wang and coworkers was a kind of thermoset elastomer with the Young s modulus of 0.282 0.025 MPa, a tensile strain of at least 267 zE 59.4%, and a tensUe strength was at least 0.5 MPa. The mechanical properties of PGS were well consisted with that of some common soft tissues. Although PGS is a thermoset polymer, its prepolymer can be processed into various shapes by solving it in common organic solvents such as 1,3-dioxolane, tetrahydrofuran, isopropanol, ethanol, and iV,M-dimethylformamide. Porous scaffolds can be fabricated by salt leaching. 

Researchers studying polypeptide and polypeptide hybrid systems have also processed vesicles using two solvents. This method usually involves a common organic solvent that solubilizes both blocks and an aqueous solvent that solublizes only the hydrophilic block. The two solvents can be mixed with the polypeptide or polypeptide hybrid system at the same time or added sequentially. The choice of organic solvent depends heavily upon the properties of the polypeptide material, and commonly used solvents include dimethylformamide (DMF) [46, 59], methanol (MeOH) [49], dimethyl sulfoxide (DMSO) [50, 72], and tetrahydrofuran (THF) [44, 55]. Vesicles are usually formed when the organic solvent is slowly replaced with an aqueous solution via dialysis or removed through evaporation however, some vesicles have been reported to be present in the organic/aqueous mixture [49]. 

The solubility properties of the polymer are very sensitive to the mode of isolation.21 PBPP is partially soluble in tetrahydrofuran immediately after precipitation from the reaction mixture, but when the polymer has been dried the solubility is less predictable. 

The physical properties of the anhydrate form and two polymorphic monohydrates of niclosamide have been reported [61], The anhydrate form exhibited the highest solubility in water and the fastest intrinsic dissolution rate, while the two monohydrates exhibited significantly lower aqueous solubilities. In a subsequent study, the 1 1 solvates of niclosamide with methanol, diethyl ether, dimethyl sulfoxide, N,/V -dimethyl formamide, and tetrahydrofuran, and the 2 1 solvate with tetraethylene glycol, were studied [62], The relative stability of the different solvatomorphs was established using desolvation activation energies, solution calorimetry, and aqueous solubilities. It was found that although the nonaqueous solvates exhibited higher solubilities and dissolution rates, they were unstable in aqueous media and rapidly transformed to one of the monohydrates. 

Water is involved in most of the photodecomposition reactions. Hence, nonaqueous electrolytes such as methanol, ethanol, N,N-d i methyl forma mide, acetonitrile, propylene carbonate, ethylene glycol, tetrahydrofuran, nitromethane, benzonitrile, and molten salts such as A1C13-butyl pyridium chloride are chosen. The efficiency of early cells prepared with nonaqueous solvents such as methanol and acetonitrile were low because of the high resistivity of the electrolyte, limited solubility of the redox species, and poor bulk and surface properties of the semiconductor. Recently, reasonably efficient and fairly stable cells have been prepared with nonaqueous electrolytes with a proper design of the electrolyte redox couple and by careful control of the material and surface properties [7], Results with single-crystal semiconductor electrodes can be obtained from table 2 in Ref. 15. Unfortunately, the efficiencies and stabilities achieved cannot justify the use of singlecrystal materials. Table 2 in Ref. 15 summarizes the results of liquid junction solar cells prepared with polycrystalline and thin-film semiconductors [15]. As can be seen the efficiencies are fair. Thin films provide several advantages over bulk materials. Despite these possibilities, the actual efficiencies of solid-state polycrystalline thin-film PV solar cells exceed those obtained with electrochemical PV cells [22,23]. 

The conformational mobility of a chromophoric main-chain polymer is often connected to its electronic structure. Therefore, changes in the UV-visible absorption spectra and/or chiroptical properties are spectroscopically observable as thermo-, solvato-, piezo-, or electrochromisms. It is widely reported that o-conjugating polysilanes exhibit these phenomena remarkably clearly.34 However, their structural origins were controversial until recently, since limited information was available on the correlation between the conformational properties of the main chain, electronic state, and (chir)optical characteristics. In 1996, we reported that in various polysilanes in tetrahydrofuran (THF) at 30°C, the main-chain peak intensity per silicon repeat unit, e (Si repeat unit)-1 dm3 cm-1, increases exponentially as the viscosity index, a, increases.41 Although conventional viscometric measurements often requires a wide range of low-dispersity molecular-weight polymer samples, a size exclusion chromatography (SEC) machine equipped with a viscometric detector can afford... 

What specific properties of these complexes have allowed isolation of five-coordinate Pt(IV), in the form of the trimethyl complex and the dihy-dridosilyl complexes These two types of complexes are significantly different, and their stability is apparently due to different factors. Comparing the trimethyl complex in Scheme 21(A) with the related but six-coordinate complexes of a similarly bulky oc-diimine ligand (98), shown in Scheme 23, is instructive. In Scheme 23A, triflate is clearly coordinated, exhibiting an O-Pt distance of 2.276(3) A (98), which is typical for Pt-coordinated triflate (108). This triflate complex A in Scheme 23 was obtained from dry tetrahydrofuran. The aqua complex cation B, also structurally characterized, was obtained from acetone containing trace water. An equilibrium between coordinated triflate and coordinated water, very likely via a common five-coordinate intermediate, was indicated by NMR spectroscopy (98). 

Anions and uncharged analytes tend to spend more time in the buffered solution and as a result their movement relates to this. While these are useful generalizations, various factors contribute to the migration order of the analytes. These include the anionic or cationic nature of the surfactant, the influence of electroendosmosis, the properties of the buffer, the contributions of electrostatic versus hydrophobic interactions and the electrophoretic mobility of the native analyte. In addition, organic modifiers, e.g. methanol, acetonitrile and tetrahydrofuran are used to enhance separations and these increase the affinity of the more hydrophobic analytes for the liquid rather than the micellar phase. The effect of chirality of the analyte on its interaction with the micelles is utilized to separate enantiomers that either are already present in a sample or have been chemically produced. Such pre-capillary derivatization has been used to produce chiral amino acids for capillary electrophoresis. An alternative approach to chiral separations is the incorporation of additives such as cyclodextrins in the buffer solution. 

SnC>2 nanoparticles have been successfully synthesized by chemical co-precipitation method using ethanol, acetone, tetrahydrofuran (THF) and ether as solvents. X-ray Diffraction (XRD), Field Emission Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) have been used to study the crystallographic and morphological properties of synthesized SnC>2 nanoparticles, while their optical properties have been studied by UV-Visible absorption spectroscopy. UV-Vis absorption spectra shows a weak quantum confinement in all the synthesized SnCL samples. The photo-catalytic activity of as-synthesized SnC>2 nanoparticles under UV irradiation has been evaluated using Methylene Blue (MB) dye as a test contaminant in water. The results showed that solvents played a key role to control the morphology and photo-catalytic activity of SnCE nanoparticles. 

Five organic solvents [acetonitrile, methanol, tetrahydrofuran (THF), acetone, and dimethylformamide], which are homogeneously miscible with water, have been used as modifiers to study the relationship of the selectivity of the solvent to the molecular properties of analytes. The polar interaction... 

Figure 4.4 Polarity, proton acceptor and dipole properties of water and organic modifier mixtures.----------------, acetonitrile, --, methanol, and---tetrahydrofuran.

W. Wang, C. Chen, L. Chen, Q. Wang, Change in structure and hydrogen storage properties of La,Mg,Ni alloy after modification by mechanical grinding in tetrahydrofuran, J. Alloys Compd. 339 (2002) 175-179. 

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