Propane fluorination

Micelle formation of our block copolymers in fluorinated solvents indicates that these polymers might act as stabilizers or surfactants in a number of stabilization problems with high technological impact, e.g., the surface between standard polymers and media with very low cohesion energy such as short-chain hydrocarbons (isopentane, butane, propane), fluorinated solvents (hexafluoroben-zene, perfluoro(methylcyclohexane), perfluorohexane) and supercritical C02. As... 

Consider abstraction of a hydrogen atom from propan( by fluorine atom. This can generate either of two propy radicals, depending on which hydrogen is attacked. 

Add the energies of propane and fluorine atom (at left (the reactants), and then the energies of 1-propyl radica (or 2-propyl radical) and hydrogen fluoride (th( products). Are these reactions exothermic or endothermic If the former, then calculate the relative concentrations 0 1-propyl radical and 2-propyl radical that would exist ii an equilibrium mixture at 298 K. Use equation (1). 

Chlorine dioxide Copper Fluorine Hydrazine Hydrocarbons (benzene, butane, propane, gasoline, turpentine, etc) Hydrocyanic acid Hydrofluoric acid, anhydrous (hydrogen fluoride) Hydrogen peroxide Ammonia, methane, phosphine or hydrogen sulphide Acetylene, hydrogen peroxide Isolate from everything Hydrogen peroxide, nitric acid, or any other oxidant Fluorine, chlorine, bromine, chromic acid, peroxide Nitric acid, alkalis Ammonia, aqueous or anhydrous Copper, chromium, iron, most metals or their salts, any flammable liquid, combustible materials, aniline, nitromethane... 

Interaction of propane, butane or 2-methylpropane with fluorine and oxygen produces peroxides. Appropriate reaction conditions are necessary to prevent explosions. 

Herein we present the synthesis of two series of fluorinated acrylate polymers and copolymers derived from commercially available hexafluoro-2-hydroxy-2(4-fluorophenyl)propane. The solubility, film-forming ability, thermal stability, and water absorption in these polymers have been studied. 

Six novel fluorinated poly(aryl ether)s containing 1,4-naphthalene moieties were synthesized in high yield using 2,2-bis[4-( 1 -naphthoxy)phenyl]hexafluoro-propane (1). Oxidative coupling ofl yielded a polymer with high 7, low moisture absorption, and low dielectric constant that could be cast into flexible films. The low dielectric constant and low moisture absorption of 6FNE may make it useful as a dielectric insulator in microelectronics applications. 

Four poly(ether ketone)s obtained from 2,2-bis[4-(4-fluorobenzoyl)-phenyl]-1,1,1,3,3,3-hexafluoropropane (9) or 2,2-bis[4-(4-fluorobenzoyl)-phenyl]propane (10) with Bisphenol AF (1) or Bisphenol A (4) are all soluble in chloroform, benzene, THF, and aprotic polar solvents such as DMF, DMAc, and NMP.15 Poly(ether ketone) from 9 and 1, which has the highest fluorine content, dissolves easily in ethyl acetate. 

Crystallinity of these hexafluoroisopropylidene-unit-containing poly(ketone)s is low except for poly(sulfide ketone) (13). The water contact angle for the fluorine-containing poly(ketone) films is high, being 98° for poly(ether ketone) (11), from 2,2-bis(4-carboxyphenyl)-l,l, l,3,3,3-hexafluoropropane(15) and 96° for poly(sulfide ketone) (13) from 15, whereas it is 78° for poly(ether ketone) from 2,2-bis(4-carboxy-phenyl)propane (16) and 74° for the poly(sulfide ketone) from 16. This result indicates that the substitution of isopropylidene units of poly-(ketone)s with hexafluoroisopropylidene units has a remarkable effect on the surface properties of poly(ketone) films. 

Mamyama et al.25 have obtained high-molecular-weight poly(benzoxazole)s by the low-temperature solution polycondensation of A,A 0,0 -tetrais(trimethyl-silyl)-substituted 2,2-bis(3-amino-4-hydroxyphenyl)-l,l,l,3,3,3-hexafluoro-propane (25) with aromatic diacids and subsequent thermal cyclodehydration of the resulting poly(o-hydroxy amide)s in vacuo. In this method, aromatic diamines with low nucleophilicity are activated more positively through the conversion to the /V-silylated diamines, and the nucleophilicity of the fluorine-containing bis(o-aminophenol) can be improved by silylation. 

In this work, results of high level ab initio SOPPA calculations of vicinal fluorine-fluorine indirect nuclear spin couplings are presented for 1,2-difluoroethene, -propene, -ethane and -propane. The four contributions (OD, OP, SD, FC) and the total value of the coupling constant are analyzed. 

As pointed out above, neither methane nor its higher homologs (ethane, propane, hexane) can be effectively metalated. The introduction of a hetero-substituent changes this outset profoundly. Second-row and third-row elements (such as silicon, phosphorus and sulfur) will not be considered in this context as they are known to acidify hydrocarbons strongly due to d-orbital resonance (or polarization) effects. But also the first-row elements nitrogen, oxygen and fluorine can distinctly facilitate the deprotonation of paraffinic hydrocarbons. 

Very strong metal-fluoroolefin bonding has also been inferred from preparative studies and the similarity of geminal 1 F-19F coupling constants in fluoroolefin complexes to those found in fluorinated cyclo-propanes (61, 85, 215). 

The most important application for bismaleimide resin is multilayer boards. The development in this area requires resins with low dielectric constants. It is well documented in the literature that fluorine containing linear polyimides show lower dielectric constants vis a vis their non-fluorinated counterparts. Recently, Hitachi Research Laboratory, Japan, reported the thermal and dielectric behaviour of fluorine-containing bismaleimides (29). The chemical structures of the fluorinated BMIs investigated are provided in Fig. 6. The non-fluorinated four aromatic rings containing BMI, 4,4 -bis(p-maleimidophenoxyphenyl) propane, was tested in comparison. 

Perfluoro-tert-butyl hypofluorite [perfluoro(2-fluoroxy-2-methylpropane), 14], readily prepared by the low-temperature fluorination of potassium or sodium perfluoro-/cr/-butoxide,812 reacts with hexafluoropropenc at low temperature to give 15 with more than 95 % regiosclcctivity, which may be explained by electrophilic attack and the formation of a fluorocarbeniuni ion, whose intervention is suggested in order to explain the production of perfluoro(l-/m-butoxy-propane) (15).12... 

The anodic oxidation of alkanes on a platinum anode in anhydrous hydrogen fluoride19 at low potentials is accompanied by exhaustive fluorination, with all of the hydrogen atoms being replaced by fluorine. Thus, the major fluorination products of methane and propane are carbon tetrafluoride and octafluoropropane, respectively. 

The result of the reaction of sulfur tetrafluoride with alcohols strongly depends on the structure of the alcohol. Simple aliphatic alcohols, such as methanol, ethanol and propan-2-ol, give alkyl ethers as the main product with only small amounts of fluoroalkanes.41 42 Yields of fluorinated products increase with increasing acidity of the hydroxy group and, in general, the reaction is only synthetically useful with alcohols equally or more acidic than tropolone (p K, = 6.42). 

Increasing the number of hydroxy groups in the substrate results in a sharp decrease in the yield of fluorinated compounds due to resinification and carbonization. This may be avoided by conducting the reactions at low temperatures in anhydrous hydrogen fluoride. Thus, the reaction of sulfur tetrafluoride with propane-1.2,3-triol (glycerol) at — 40 C gives 3-fluoro-propane-l,2-diyl sulfite (5) in high yield.60... 

All the chlorine atoms in hexafluoro-2-(trichloromethyl)propan-2-ol (1) are substituted by fluorine with antimony(V) fluoride under mild conditions.91... 

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