Fluorocarbon Derivatives Research Articles

Morphological control of bicontinuous phase-separated patterns by preparing mixed monolayers using non-amphiphilic s-triazine derivatives with three fluorinated chains

In this study, the morphogenesis of the bicontinuous phase separation in mixed monolayers of a non-amphiphilic fluorocarbon derivative without a hydrophilic group and long-chain fatty acids is discussed. These fluorocarbon derivatives contain an s-triazine ring and three fluorocarbon chains. The corresponding fluorocarbon derivatives exhibit high crystallinity in the monolayers, allowing them to maintain crystalline regularity even in the "sea" region of the mixed monolayer that exhibits phase separation. In controlling the bicontinuous pattern, the formation of complex phase-separated morphology in the mixed system of fluorine-based derivatives and comb polymers, along with the high concentration and low diffusion conditions in the mixed hydrocarbon/fluorocarbon system, were examined. It was observed that the condensed phase domains became angular shape at a low temperature (5 °C), and the surface approached a bicontinuous feature at a high temperature (40 °C). With the formation of hydrogenated condensed domains, the "sea" region of fluorocarbon chains lost its order. At this point, the shape of the nanodomains tended to become more circular.

Editorial

Editorial

Robert Neville Haszeldine. 3 May 1925—13 October 2016

Robert Neville Haszeldine was particularly associated with fluorine chemistry. He did outstanding synthetic work on inorganic and organic fluorocarbon derivatives, including fluoroalkyl Grignard and lithium reagents; fluoroalkyl derivatives of mercury, phosphorus, nitrogen and sulphur; fluoroalkyl silicones; fluoro-olefins; and hexafluorobenzene, pentafluoropyridine and their derivatives. He also made major contributions to the study of free-radical addition reactions and developed new routes to carbenes. He discovered a new class of polymers by copolymerizing a nitroso-compound with an olefin or fluoro-olefin to give the –N–O–C–C– repeating unit. His research revealed a mastery of modern ideas on the mechanism of organic and inorganic reactions coupled with outstanding experimental skill and originality. His work yielded over 500 publications, plus more than 150 patents concerning industrial applications of fluorocarbons, and he was awarded several medals. As head of chemistry at the University of Manchester Institute of Science and Technology (UMIST) he developed a world-class fluorine research group and oversaw a new building for the department, which became one of the largest in the UK. Later, as principal of UMIST, he instigated academic developments just before the government severely cut university funding and imposed full-cost fees for overseas students, drastically reducing UMIST's income. His crisis plan for budget cuts proved divisive, and he took early retirement, citing intolerable financial pressures on UMIST. Initially, he continued with consultancy; later, he became deeply involved with his local community, and created a garden that received local and national recognition, including a plant variety named after him.

Adsorption Separation of R‐22, R‐32 and R‐125 Fluorocarbons using 4A Molecular Sieve Zeolite

AbstractGlobal warming has received great attention over the past decades, which is having costly impacts on our communities, health and climate. Fluorocarbon derivatives that are widely used in various industries such as refrigerants and solvents have significant effect on global warming due to their high global warming potential. Recycling and reuse of fluorocarbons help not only to minimize the environmental release but also to fulfill the future demand with the rapid phase out of some of the fluorocarbons. Herein, our work reports the adsorption separation of mixtures of difluoromethane (R‐32), chlorodifluoromethane (R‐22) and pentafluoroethane (R‐125) into their pure components using 4A molecular sieve zeolite under ambient conditions. Pure gas equilibrium isotherm measurements indicate that the uptake capacity follows the order of R‐32 > R‐22 > R‐125 on 4A zeolite with negligible uptake capacity for R‐125. As evidenced by the gas breakthrough results, R‐32, R‐22 and R‐125 could be successfully separated into pure components using 4A zeolite. Steric effects were responsible for the separation of R‐32 and R‐22 from R‐125 while slower uptake rate of R‐22 compared to R‐32 facilitated the successful separation of R‐22 from R‐32. The regular pore structure, excellent match of pore size of 4A zeolite with the molecular sizes of the fluorocarbon make the product gases very pure, to the extent of direct industrial applications.

Smectic C Mesogens with Terminal Perfluoroalkyl Chains

The fluorocarbon derivatives were synthesized. Liquid crystalline states were studied by DSC and microscopic observation. TNI of those compounds were from 161.2°C to 191.7°C, which represented those compounds had very good liquid crystalline stability. Smectic C temperature range was 91.7°C for F8H2OPMB, 54.9°C for F8H2OPCB, 41.1°C for F8H2OPMB-F, 36.2°C for F8H2OMB, 27.4°C for F8H2OPCB-F, and 10.8°C for F6H2OMB. The structures of F8H2OPCB and F8H2OPCB-F at room temperature were tilted herringbone packing of two aromatic ring ester cores (smectic K phase) and perfluoroalkyl chains were located up and down alternatively. Smectic K was proved by high intensity of 003 and 004 reflections in X-ray diffraction.

Fluorocarbon adsorption in hierarchical porous frameworks

Metal-organic frameworks comprise an important class of solid-state materials and have potential for many emerging applications such as energy storage, separation, catalysis and bio-medical. Here we report the adsorption behaviour of a series of fluorocarbon derivatives on a set of microporous and hierarchical mesoporous frameworks. The microporous frameworks show a saturation uptake capacity for dichlorodifluoromethane of >4 mmol g(-1) at a very low relative saturation pressure (P/Po) of 0.02. In contrast, the mesoporous framework shows an exceptionally high uptake capacity reaching >14 mmol g(-1) at P/Po of 0.4. Adsorption affinity in terms of mass loading and isosteric heats of adsorption is found to generally correlate with the polarizability and boiling point of the refrigerant, with dichlorodifluoromethane > chlorodifluoromethane > chlorotrifluoromethane > tetrafluoromethane > methane. These results suggest the possibility of exploiting these sorbents for separation of azeotropic mixtures of fluorocarbons and use in eco-friendly fluorocarbon-based adsorption cooling.

Mass spectrometry of fluorocarbon‐labeled glycosphingolipids

A method for generation of novel fluorocarbon derivatives of glycosphingolipids (GSLs) with high affinity for fluorocarbon phases has been developed, and their potential applications to mass spectrometry (MS)-based methodologies for glycosphingolipidomics have been investigated. Sphingolipid ceramide N-deacylase (SCDase) is used to remove the fatty acid from the ceramide moiety, after which a fluorocarbon-rich substituent (F-Tag) is incorporated at the free amine of the sphingoid. In initial trials, a neutral GSL, globotriaosylceramide (Gb(3)Cer), three purified bovine brain gangliosides, and four fungal glycosylinositol phosphorylceramides (GIPCs) were de-N-acylated, derivatized by prototype F-Tags, and recovered by solid phase extraction on fluorocarbon-derivatized silica (F-SPE). The efficacy of SCDase treatment of GIPCs was here demonstrated for the first time. Compatibility with subsequent per-N,O-methylation was established for the F-tagged Gb(3) Cer and purified gangliosides, and extensive mass spectra (MS(1) and MS(2)) consistent with all of the expected products were acquired. The potential use of F-tagged derivatives for a comprehensive MS based profiling application was then demonstrated on a crude ganglioside mixture extracted from bovine brain. Finally, a simple trial in microarray format demonstrated fixation of F-tagged G(M1) ganglioside to a fluorous glass surface, with the glycan intact and available for interaction with a fluorescent derivative of cholera toxin B chain. The methods described thus provide a new avenue for rapid GSL recovery or cleanup, potentially compatible with a variety of platforms for mass spectrometric profiling and structure analysis, as well as parallel analysis of functional interactions.

Interaction between Fluorocarbon End-Capped Poly(ethylene oxide) and Cyclodextrins

Well-defined fluorocarbon end-capped poly(ethylene oxide) (PEO), known as F-HEUR, were synthesized by varying both fluorocarbon end groups and PEO chain length. Their solution properties were studied and compared with those of hydrogenated carbon end-capped PEO. Variation of the end-capped functional group from −C6F13 to −C8F17 gave rise to a significant shift in the solution rheological properties. The interaction between different cyclodextrins and these fluorocarbon derivatives of PEO was systematically examined by rheological, dynamic light scattering (DLS), isothermal titration calorimetric (ITC), and 19F NMR techniques. The viscosity of F-HEUR solution was drastically reduced in the presence of methylated β-cyclodextrin (m-βCD) due to the disruption of intermolecular hydrophobic associations, but not observed for α- and γ-cyclodextrins. The destruction of F-HEUR network structure in the presence of m-βCD was reflected by the large reduction in the plateau modulus ( ). The activation energies (Ea) determined from zero-shear viscosity decreased with m-βCD concentration until a molar ratio of 2; thereafter it remained constant. At high m-βCD concentration, subtle difference was observed for the complexes produced by −C6F13 and −C8F17 hydrophobic moieties. The inclusion complex formation between m-βCD and different fluorocarbon groups derived from ITC thermograms revealed a stoichiometry of 1:1 for C6F13 but 1:1 and 2:1 inclusion complexes for C8F17 at different m-βCD concentrations. DLS results showed a different mechanism for C6F13 and C8F17 fluorocarbon hydrophobes, which were in agreement with the results deduced from activation energies and 19F NMR spectra. A mathematic model was adopted to describe the relationship between and m-βCD concentration.

Quantitative Four‐State Conformational Analysis by Ring Current NMR Anisotropy: A Family of Molecules Capable of Intramolecular π‐Stacking

AbstractA novel, multi‐state, conformational analysis based on the magnetic anisotropy of molecules undergoing fast dynamic exchange is described. Calculated chemical shift tensors combined with experimental data from proton NMR studies were used to quantify conformational distributions as a function of solvent and temperature for a hydrocarbon and two fluorocarbon derivatives of N,N′‐[1,3‐phenylenebis(methylene)]bis(2‐phenylpyridinium) dibromide. Inspection for adequate analyses involved confirming that the mathematical expressions conserved magnetization (mass). Enthalpic parameters from VT‐NMR gave some indication of the nature of the impact of solvent on conformation. Results indicated that electrostatic interactions between aromatic rings can strongly impact organic conformation in solution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Hexafluorobenzene photochemistry: wellspring of fluorocarbon structures.

Ultraviolet irradiation of hexafluorobenzene in the vapor phase gives exclusively its Dewar valence isomer, from which a wealth of highly fluorinated compounds has been derived. Photoexcited in solution, hexafluorobenzene is capable of cycloaddition with a variety of unsaturated molecules. Like the Dewar benzene, resulting adducts have served as intermediates en route to many new fluorocarbons and fluorocarbon derivatives.

Relative boiling points of fluoro-ethers, fluoroamines and other fluorocarbon derivatives to fluorocarbons

The proposed equation log T=2.2+0.42 log n for predicting boiling points of perfluorocarbons with n carbons was found to be less accurate for predicting boiling points of F-ethers and tertiary F-amines than using data from those fluorocarbons with ( n+1) carbons less 22° and 12°, respectively. A similar treatment can predict boiling points of perfluoro polyethers. These constant deductions represent extra intermolecular repulsions caused by the isoelectronic replacement of CF 2 by O and CF by N. Deductions are not required to predict boiling points of perfluoro primary and secondary amines, acyl fluorides, N-acylfluorides, ketones and isocyanates via isoelectronic replacements to produce n-perfluorocarbons.

Characterization of the lipophilicity of fluorocarbon derivatives containing halogens or hydrocarbon blocks

The lipophilicity of highly lipophilic fluorochemicals containing halogens or hydrocarbon blocks has been assessed using a new critical solution temperature ( CST) method based on n-bromoalkanes. Measurements of CST are made as a function of n-bromoalkane chain length and extrapolated to n-bromohexane for reference. The CST values using n-bromohexane as the reference are much higher than those observed for n-hexane, thereby moving the CST for lipophilic fluorochemicals into a measurable temperature range. The new method correlates well with both CST hex values and olive oil solubilities. The relative lipophilicities of various classes of highly lipophilic fluorochemicals are delineated, and a group additivity scheme for estimating CST Brhex values is elucidated.

A mass spectrometric method for the detection of various fluorocarbon derivatives in synthetic flexible and rigid foams

Isolation and identification of CFCs, that may be contained in synthetic flexible and rigid foams, was carried out by a simple mass spectrometry technique. This method was then extended to the identification of potential substitutes of CFCs, the Hydrochlorofluorocarbons, HCFCs, and the Hydrofluorocarbons, HFCs.

Fluorocarbon derivatives of nitrogen. Part 19. Synthesis and mass spectrometric analysis of some pyridinium (tetrafluoro-4-pyridyl)-methylides

Nine new pyridinium methylides have been synthesised via S NAr displacement of the 4-fluorine from pentafluoropyridine with pyridinium phenacylide [ → py +C̄(COPh)C 5F 4N-4] and a range of pyridinium alkoxycarbonylmethylides [ → py +C̄(CO 2R)C 5F 4N-4, R = Me, Et, Pr n, Pr i, CH 2CCl 3, CH 2CF 3, CH 2Ph, CH 2CH 2Ph]. A detailed analysis of the mass spectrometric fragmentation patterns for the alkoxycarbonyl compounds has been carried out. Spectroscopic data has also been obtained for pyridinium methylides synthesised from pyridinium ethoxycarbonylmethylide and 3-chlorotetrafluoropyridine or octafluorotoluene.

Fluorocarbon derivatives of nitrogen. Part 18 [1]. Synthesis of fluorinated indolizines through reactions of pyridinium ethoxycarbonylmethylide or pyridinium phenacylide with perfluoropropene, perfluorobut-2-yne and 3,3,3-trifluoropropyne

3-Ethoxycarbonyl-2-fluoro-1-trifluoromethylindolizine ( 6), 3-ethoxycarbonyl-1,2-(bistrifluoromethyl)indolizine ( 8), 3-ethoxycarbonyl-1-trifluoromethylindolizine ( 10) and 3-ethoxycarbonyl-2-perfluoroheptylimidazo[1,2- a]pyridine ( 12) have been obtained via trapping of pyridinium ethoxycarbonylmethylide with perfluoropropene, perfluorobut-2-yne, 3,3,3-trifluoropropyne and perfluorooctanenitrile respectively. Similarly, 2-fluoro-1-trifluoromethyl-3-phenacylindolizine ( 7), 1,2-bis(trifluoromethyl)-3-phenacylindolizine ( 9),and 3-phenacyl-1-trifluoromethylindolizine ( 11), have been obtained via reaction of pyridinium phenacylide with perfluoropropene, perfluorobut-2-yne, and 3,3,3-trifluoropropyne respectively. Alkaline hydrolysis of ( 8) gave 1,2-bis(trifluoromethyl)indolizine-3-carboxylic acid ( 16), which was decarboxylated thermally to 1,2-bis(trifluoromethyl)- indolizine ( 15).

Self-Organization of Solvophobic, Double-Chained Fluorocarbon Derivatives in Organic Media

Abstract A novel type of compounds which contain two fluorocarbon chains and one flexible hydrocarbon chain gave bilayer-based molecular assemblies in organic solvents. The regularity of the assemblage was supported by specific incorporation of benzene.

Fluorocarbon derivatives of nitrogen. Part 16 [1]. Synthesis of some unsymmetrical aromatic azo-compounds via diazotisation of fluorinated aryl- and [formula omitted]-heteroaryl-amines in hydrofluoric or sulphuric acid [2

Coupling reactions of the type Ar FN + 2 + ArH → Ar FNNAr + H + have been accomplished between fluorinated arenediazonium ions selected from the benzenic, pyridinic and pyrimidinic classes [Ar F  C 6F 5, 4CF 3C 6F 4, 4C 5F 4N, 4z.sbnd;C 5F 3N.Cl3, 4C 5F 2N.Cl 23,5, 2C 5F 3N.CF(CF 3)24, 4C 4F 3N 2] and one or more aromatic compounds activated towards electrophilic attack (ArH  1,3,5,ME 3C 6H 3, 1,3,5Et 3C 6H 3, MeOC 6H 6, and napth-2-ol). The diazonium ions were generated by addition of solid sodium nitrite to solutions of the amines Ar FNH 2 in anhydrous hydrogen fluoride, 80% hydrofluoric acid, or 98% sulphuric acid mixed with glacial acetic acid and propionic acid. This work has established that perfluorinated arenediazonium ions rank amongst the most electrophilic species of their general class.

Infrared emission spectroscopy in H2/F2 and CH4/F2 premixed flames

AbstractThe infrared emission corresponding to the Δ v=1 transitions of the vibrationally excited HF (1 < =v< =3) has been recorded in rich premixed hydrogen‐fluorine and methanefluorine flames burning at various pressure (1.3–9 torr). The initial hydrogen and fluorine element content was identical in both CH4‐and H2‐ fluorine flames.The rational temperature profiles have been determined as well as in H2/F2 flames than in CH4/F2 ones. The analysis of the experimental data has put forward the occurrence of an equilibrated vibrational population relatively early in the burnt gases region of flames burning at pressures higher than 5 torr. From these evidences, profiles of the relative mole fractions of HF in its vibrationally excited states (1 < =v< =3) have been established in both series of flames. The absolute total concentrations of HF have been deduced by considering the Lewis number equals to one and therefore the absolute mole fraction profiles of the individual vibrationally excited HF (0 < =v< =3) have been determined.Besides the well‐known mechanism of the HF formation in H2/F2 systems it appears clearly that in CH4/F2 flames the final concentration of fluorocarbon derivatives are close to those of fluorhydric acid. This evidence indicates that in rich methane‐fluorine flames the reaction CH3 + F2 → CH2F + HF and subsequent reactions of CH2F are important in addition of the primary attack of methane CH4 + F → CH3 + HF and CH4 + F → CH3F + H.

ChemInform Abstract: FLUOROCARBON DERIVATIVES OF NITROGEN. PART VII. REACTION OF N‐IMINOPYRIDINIUM M YLIDE WITH PERFLUORO‐1‐AZACYCLOHEXENE, PERFLUORO‐2‐AZAPROPENE, AND PERFLUOROACETONITRILE

Chemischer InformationsdienstVolume 13, Issue 36 Heterocyclic Compounds ChemInform Abstract: FLUOROCARBON DERIVATIVES OF NITROGEN. PART VII. REACTION OF N-IMINOPYRIDINIUM M YLIDE WITH PERFLUORO-1-AZACYCLOHEXENE, PERFLUORO-2-AZAPROPENE, AND PERFLUOROACETONITRILE R. E. BANKS, R. E. BANKSSearch for more papers by this authorS. M. HITCHEN, S. M. HITCHENSearch for more papers by this author R. E. BANKS, R. E. BANKSSearch for more papers by this authorS. M. HITCHEN, S. M. HITCHENSearch for more papers by this author First published: September 7, 1982 https://doi.org/10.1002/chin.198236174AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume13, Issue36September 7, 1982 RelatedInformation

Fluorocarbon derivatives of nitrogen. Part 6. Reactions of some perfluorinated nitroso-compounds with hydrogen sulphite ion: conversion of fluorocarbon olefins into perfluoro-ketone oximes

The sequence of events R1FR2FCFNO + HSO3– aq. → R1FR2FCFN(OH)SO3–→ R1FR2FCFNHOH → R1FR2FCNOH is proposed to account for the production of N-trifluoromethylhydroxylamine, perfluoropropanohydroximoyl fluoride, perfluoroacetone oxime, and perfluorocyclobutanone oxime when the nitroso-compounds CF3NO, n-C3F7NO, (CF3)2CFNO, and [graphic omitted]FNO, respectively, are treated with aqueous potassium hydrogen sulphite; understandably, perfluoro-1-nitrosopropane reacts with the same reagent in the presence of lead(IV) oxide to give the purple water-soluble oxyl n-C3F7N(O˙)SO3–K+ Since perfluoro-2-nitrosopropane and perfluoronitrosocyclobutane are easily obtained via the route R1FCFCFRF→(with KF–CF3CO2Ag) R1FCFAgCF2RF→(with NOCl) R1FCF(NO)CF2RF(R1F= CF3, RF= F; R1FRF= CF2CF2)(RFCF2= R2F), the reductive defluorination with aqueous hydrogen sulphite anion completes a fluorocarbon olefin → fluorocarbon ketone oxime conversion.