Mark L. Robin

Method for fluorodecarboxylation

The present invention is directed to a method for replacing a carboxylic acid group with a fluorine group in a halogenated aliphatic carboxylic acid compound having the formula, R-COOH, to prepare a fluorinated product having the formula, R-F, wherein R is a halogenated aliphatic group including straight- and branched-chain aliphatic groups selected from the group consisting of halogenated aliphatic and alkoxy-substituted halogenated aliphatic groups, wherein the method comprises the steps of (a) reacting the halogenated aliphatic carboxylic acid compound with bromine trifluoride, and (b) recovering the fluorinated product.

Electron-Impact Induced Molecular Fluoresence Spectroscopy

Abstract By the bombardment of gaseous molecules with monoenergetic electrons the molecules can be electronically excited and/or fragmented, depending upon the energy supplied by the electrons. Any fragments which may be produced also have the possibility of being produced in electronically (as well as vibrationally and rotationally) excited states. The electronically excited molecules and fragments both possess the possibility of radiative decay (fluorescence). The measurement of this fluorescence as a function of both electron energy and photon wavelength is termed “electron-impact induced fluorescence spectroscopy.” A plot of fluorescence intensity as a function of the electron energy at a given photon wavelength is generally referred to as an “excitation function,” which is exactly analogous to the excitation spectrum which can be obtained in conventional (optically excited) fluorescence spectrometry. A plot of the fluorescence intensity as a function of photon wavelength at a given electron energy is...

Low Temperature Fluorination of Aerosol Suspensions of Hydrocarbons Utilizing Elemental Fluorine.

Abstract : Ring opening during the aerosol direct fluorination of cyclic ketones can be circumvented by the aerosol direct fluorination of the appropriate methoxycycloalkanes or the ethylene glycol ketals of the cyclic ketones followed by sulfuric acid hydrolyses of the perfluorinted analogs. Aerosol direct fluorinations of methoxycyclopentane and methoxycyclohexane produce their respective perfluoroanalogs in effluent concentration of 57% and 90% by weight and in 22% and 32% isolated yields respectively. Sulfuric acid hydrolyses at 340 to 360 C of the F-methoxycycloalkanes produced F-cyclopentanone (89% yield, 61% conversion) and F-cyclohexanone (82% yield, 28% conversion) respectively. The aerosol fluorinations of the ethylene glycol ketals of cyclopentanone and cyclohexanone produce F-dioxaspiro(4.4)nonane and F-dioxaspiro(4.5)decane in effluent concentrations of 74% and 76% by weight and in 14% and 12% isolated yields respectively. Sulfuric acid hydrolyses at 500 C produced F-cyclopentanone (45% yield, 23% conversion) and F-cyclohexanone (100% yield, 36% conversion) respectively. Physical loss of starting material caused by condensation within the aerosol fluorinator is the major reason for reduced yields. Hydrolysis yields are based on starting materials consumed and not recovered. (Author)

Aerosol direct fluorination: orthoesters, syntheses of perfluoromethylorthocarbonate and perfluoroethylene orthocarbonate

Abstract The extension of aerosol direct fluorination techniques to orthoesters is described. Perfluorinated orthocarbonates can be isolated in modest yield from the direct fluorination of the analogous hydrocarbon orthocarbonates. They are stable, relatively unreactive and highly volatile. From the aerosol fluorination of tetramethyl orthocarbonate perfluorotetramethyl orthocarbonate (8%) and perfluorotrimethyl orthoformate (19%) can be isolated. The fluorination of ethylene orthocarbonate produces perfluoroethylene orthocarbonate (17%) and a small amount of a second product presumed to be perfluoroethylene carbonate. The fluorination of trimethyl orthoacetate resulted in the isolation of perfluoro-1,1-dimethoxyethane (24%). All starting materials undergo extensive beta scission during fluorination a result of alkoxy stabilized radicals.