Polyfluorinated Alcohol Research Articles

1,1,1,3,3,3-Hexafluoro-2-propanol (HFIP) as a reusable promoting medium for the catalyst-free and green synthesis of dihydropyrano[2,3-c]pyrazole scaffolds

A manufactured protocol that is both helpful and free of catalyst has been presented for the production of dihydropyrano[2,3-c]pyrazole frameworks in polyfluorinated alcohol as a reusable promoting medium. All reactions are completed quickly, and the products are obtained in astounding yields. Notably, the convenient approach has remarkable yields, avoids the use of hazardous solvents or reagents, is simple to operate, and only requires one pot. The 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) was extremely stable and could be repeated four times without significant basic alteration or action, making it ideal for large-scale and organic production.

Polyfluorinated alcohol as a reusable media promoted catalyst-free green synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives

A green way to catalyst-free one-pot production of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives is described. It uses the Knoevenagel-Michael cyclic condensation method and polyfluorinated alcohol as a reusable promoting medium. This method follows the rules of green chemistry. Carrying out the reactions takes much less time while obtaining products with outstanding yields. This eco-friendly method uses safe reactions, doesn't need to be separated with column chromatography, is easy to produce and work-up, doesn't need a catalyst, is affordable and simple, and is cost-effective. Moreover, green 2,2,2-trifluoroethanol (TFE) is very stable and can be used again for 4 times without any major changes or loss of effectiveness. This makes it very useful for protecting the environment during industrial activities.

Wear of a Composite Based on Polyurethane, Polyfluorinated Alcohol, Montmorillonite, and Polytetrafluoroethylene

Wear of a Composite Based on Polyurethane, Polyfluorinated Alcohol, Montmorillonite, and Polytetrafluoroethylene

Atmospheric Fate of a New Polyfluoroalkyl Building Block, C3F7OCHFCF2SCH2CH2OH.

Many per- and polyfluoroalkyl substances (PFAS) have been regulated or phased-out of usage due to concerns about persistence, bioaccumulation potential, and toxicity. We investigated the atmospheric fate of a new polyfluorinated alcohol 2-(1,1,2-trifluoro-2-heptafluoropropyloxy-ethylsulfanyl)-ethanol (C3F7OCHFCF2SCH2CH2OH, abbreviated FESOH) by assessing the kinetics and products of the gas-phase reaction of FESOH with chlorine atoms and hydroxyl radicals. Experiments performed in a stainless-steel chamber interfaced to an FTIR were used to determine reaction kinetics and gas-phase products. We report reaction rate constants of k(Cl + FESOH) = (1.5 ± 0.6) × 10-11 cm3 molecule-1 s-1 and k(OH + FESOH) = (4.2 ± 2.0) × 10-12 cm3 molecule-1 s-1. This leads to a calculated FESOH gas-phase lifetime of 2.8 ± 1.3 days with respect to reaction with OH, assuming [OH] = 106 molecule1 cm-3. Gas-phase products of FESOH oxidation included at least two aldehydes, likely C3F7OCHFCF2SCH2C(O)H and C3F7OCHFCF2SC(O)H, and secondary products including COF2, SO2 and C3F7OC(O)F. Additional gas-phase experiments performed in a Teflon chamber were used to assess aqueous products by collecting gaseous samples offline into an aqueous sink prior to analysis with ultrahigh performance liquid chromatography-tandem mass spectrometry, resulting in four acidic products: C3F7OCHFCF2SCH2C(O)OH, C3F7OCHFCF2S(O)(O)OH, C3F7OCHFC(O)OH, and perfluoropropanoic acid (C2F5C(O)OH).

Free-Radical-Promoted Dehydrogenative Coupling of Polyfluorinated Alcohol with Quinone, Chromone, and Coumarin.

A free-radical-mediated dehydrogenative cross-coupling reaction of polyfluorinated alcohol with quinone, coumarin, and chromone was developed. It provides a sustainable and practical strategy for installation of fluorine atom into organic molecules by using polyfluorinated alcohols.

X-Ray Structure and PMR Spectra of Polycaproamide Modified by a Polyfluorinated Alcohol

Effects on polycaproamide structure of a polyfluorinated alcohol immobilized on montmorillonite clay nanoparticles were studied using x-ray structure analysis and broad-line PMR spectroscopy. An exfoliated composite formed and caused the crystal and molecular structures of this heterochain polymer to reorganize. A composite based on the polyfluorinated alcohol changed the mobility of macromolecular chain segments and increased the fraction of planar trans-conformations.

Investigation of Supermolecular Structure of Fluorine-Containing Polyethyleneterephthalate Monofibers

The effect of a new modifier based on a polyfluorinated alcohol immobilized on montmorillonite nanoclay on the supermolecular structure of polyethyleneterephthalate was studied by Fourier IR spectroscopy, x-ray structural analysis, DSC, DMA, and atomic-force microscopy (AFM). It was established that the effect of the fluorine-containing modifier, involving reorganization of the molecular and crystal structure of the polymer, is complex in nature, leading to an increase of the degree of crystallinity and raising the level of surface uniformity in the obtained polyester nanofibers.

The Production of Fluorine-Containing Composite Materials Based on Polydieneurethane and Montmorillonite

The effect of organomineral complexes of 1,1,3-trihydroperfluoropropanol-1 (modifier) with layered aluminosilicate montmorillonite (LAM) as filler on the structure and properties of fluorine-containing polydieneurethane (FPU) was investigated. The modifier and the LAM were introduced into the FPU at the stage of its production. Using a combination of methods – X-ray diffraction analysis (DRON-3), electron microscopy (Versa 3D DualBeam, USA), and Fourier IR spectroscopy (Nicolet-6700, USA) – we studied features of the layer separation of LAM in the elastomer matrix as a function of the modifier concentration. It was shown that FPU specimens filled with LAM containing 5.0% polyfluorinated alcohol disintegrate better and possess a higher resistance to thermooxidative ageing.

Structural and chemical modification of polycaprolactam with a composite based on a polyfluorinated telomeric alcohol

The influence exerted on the supramolecular structure and properties of polycaprolactam by new composites based on 1,1,5-trihydroperfluoro-1-pentanol immobilized on montmorillonite support, introduced into the polymer melt, was studied. As found by electron microscopy and X-ray diffraction analysis, the layered structure of the fluorinated organoclay undergoes delamination in the bulk of the polymer matrix with the formation of an exfoliated nanocomposite. The modifier exerts a complex effect on the caprolactam structure, consisting in changes in the size of supramolecular formations and redistribution of the fraction of α- and γ-crystalline forms, which favors enhancement of the thermal oxidation resistance of the material.

Removal of acid-labile protecting or anchoring groups in the presence of polyfluorinated alcohol: Application to solid-phase peptide synthesis

We describe herein a new method for cleaving from resin and removing acid-labile protecting groups in solid-phase peptide synthesis in the presence of a polyfluorinated alcohol (either trifluoroethanol, TFE, or hexafluoroisopropanol, HFIP). It was shown that 0.1 M HCl in hexafluoroisopropanol or trifluoroethanol removes the acid-labile protecting groups commonly used in Fmoc SPPS for the protection of amino acid side-chains, such as t-butyl ester and ether, Boc, trityl, and Pbf groups including the most acid-resistant p-hydroxymethylphenoxyacetyl group (HMPA), p-benzyloxy benzyl ester (Wang resin), Rink amide, and peptide amide linker (PAL). The addition of 5–10% of a hydrogen-bonding solvent was shown to considerably retard or even fully inhibit the reaction. However, nonhydrogen-bonding solvents, such as dichloromethane, do not slow down the reaction.

A TD‐DFT Study on the Effect of Intermolecular Hydrogen Bonding on the Photophysical Properties of N‐Methyl‐1,8‐naphthalimide

AbstractThe effect of intermolecular hydrogen bonding on the photophysical properties of N‐methyl‐1,8‐naphthalimide (2) has been investigated by time‐dependent density functional theory (TD‐DFT) method. The UV and IR spectra of 2 monomer and its hydrogen‐bonded complexes formed with 2,2,2‐trifluoroethanol (TFE) 2+TFE and 2+2TFE have been calculated, which confirm the presence of intermolecular hydrogen bonding interactions between the carbonyl groups of the aromatic imide and the hydroxyl group of the polyfluorinated alcohol. The absorption and fluorescence intensities going from 2 monomer via hydrogen‐bonded complex 2+TFE to 2+2TFE were found to be gradually enhanced with the wavelength gradually red‐shifted. The enhancements of the fluorescence intensities from 2 monomer to hydrogen‐bonded complexes 2+TFE and 2+2TFE were attributed to the decrease of the intersystem crossing (ISC) efficiency from the first excited singlet state S1 1(ππ*) to the second excited triplet state T2 3(nπ*), whose energy was increased relative to its ground state due to the intermolecular hydrogen bonding interactions.

Synthesis of di(1,1,3-trihydroperfluoropropoxy)methane and di(1,1,3-trihydroperfluoropropoxy)ethane

The synthesis of acetal I was accomplished by the reaction of 1,1,3-trihydroperfluoropropanol III with paraformaldehyde in the presence of 96% sulfuric acid at room temperature in 20–24 h. Yield of acetal I was 27%. At the use of dry hydrogen chloride the yield of I increases to 43%. The notable increase in the yield of acetal I is probably due to α-chloroether formation as an intermediate compound followed by its reaction with the next molecule of polyfluorinated alcohol. Therefore, the most effective approach to polyfluorinated acetals is the reaction of α-chloroethers with polyfluorinated alcohols. Evidently the optimum conditions of α-chloroethers formation may be selected (without isolation of the α-chloroethers) varying the amount of added HCl.

New extraction systems based on organophosphorus compounds and crown ethers in polyfluorinated alcohol

New extraction systems based on organophosphorus compounds and crown ethers in polyfluorinated alcohol

The effect of the chemical structure of polyfluorinated alcohols on the tribological properties of poly-e-caproamide

The paper presents investigation results of tribological properties of model poly-ɛ-caproamide compositions modified by 0.1 wt % polyfluorinated alcohols of the formula H(CF2CF2) n CH2OH, where n = 1–3. The methods of X-ray photoelectron spectroscopy, X-ray diffraction analysis, the determination of the limiting wetting angle and microhardness, and thermomechanical analysis were used in this work. The plasticizing role of polyfluorinated alcohols and the orientation effect of poly-ɛ-caproamide most expressed in the compositions of polyfluorinated alcohol with n = 1 have been established. The modified poly-ɛ-caproamide displays by far a lower friction coefficient and a higher wear resistance as compared to the original one. The increased amount of-CF2-CF2-groups in the alcohol molecules exerts an advantageous effect on improving the tribooxidative stability of the modified poly-ɛ-caproamide.

Effect of 1,1,5-trihydroperfluoropentanol on the structure of unoriented poly(ɛ-caproamide) films

A change in the X-ray patterns of unoriented poly(ɛ-caproamide) films cast from poly(ɛ-caproamide) solutions in formic acid in the presence of 1,1,5-trihydroperfluoropentanol has been examined. It has been shown that the polyfluorinated alcohol increases the proportion of polymer molecules in the planar trans conformation owing to their transition from the gauche conformation constituting the amorphous phase and facilitates formation of hydrogen-bonded layers of macromolecules oriented perpendicular to the film plane.

Electrophilic aromatic chlorination and haloperoxidation of chloride catalyzed by polyfluorinated alcohols: a new manifestation of template catalysis.

We have demonstrated that a polyfluorinated alcohol, 2,2,2-trifluoroethanol, solvent enables haloperoxidase type activity and the oxychlorination of arenes (benzene and its alkylated derivatives) without a metal catalyst. The polyfluorinated alcohol has a dual function; it catalyzes electrophilic chlorination of less reactive arenes by several orders of magnitude and oxidation of chloride at lower H+ concentrations. DFT calculations show that a complementary charge template in the transition state explains the catalysis of the electrophilic chlorination.

Use of Fluorine-Containing Compounds for Modification of Polycaproamide

The possibility of increasing the fireproof characteristics of fluorine-containing PCA by additional incorporation of phosphorus- and phosphorus—silicon-containing flame retardants was investigated. Samples of modified PCA with an oxygen index of 28-29% were obtained with these flame retardants. It was found that polyfluorinated alcohol—T-2 fireproofing compound and polyfluorinated alcohol—microencapsulated T-2 fireproofing compound systems alter the direction of the processes that take place in the basic stage of thermal decomposition of the polymer by decreasing the amount and rate of liberation of volatile products and alter the composition of the carbonized residue.