Using three different approaches, racemic 1-(perfluoroalkyl)ethylamines were synthesized from perfluoroalkyl iodides or perfluoroalkanoic acids, and further transformed to the corresponding N,N′-disubstituted ethane-1,2-diimines and ethane-1,2-diamines as mixtures of diastereoisomers. Their cyclization afforded imidazolium or dihydroimidazolium salts, which led to silver or palladium complexes bearing
The gas phase tropospheric removal of fluoroaldehydes (CxF2x+1CHO, x = 3, 4, 6)
作者:G. Solignac、A. Mellouki、G. Le Bras、Mu Yujing、H. Sidebottom
DOI:10.1039/b703741b
日期:——
The rate coefficient of the OH reaction with the perfluoroaldehydes C3F7CHO and C4F9CHO have been determined in the temperature range 252–373 K using the pulsed laser photolysis–laser induced fluorescence (PLP-LIF) method: kC3F7CHO+OH = (2.0 ± 0.6) × 10−12 exp[−(369 ± 90)/T] and kC4F9CHO+OH = (2.0 ± 0.5) × 10−12 exp[−(356 ± 70)/T] cm3 molecule−1 s−1, corresponding to (5.8 ± 0.6) × 10−13 and (6.1 ± 0.5) × 10−13 cm3 molecule−1 s−1, respectively, at 298 K. The UV absorption cross sections of these two aldehydes and CF3(CF2)5CH2CHO have been measured over the range 230–390 nm at 298 K and also at 328 K for CF3(CF2)5CH2CHO. The obtained results for C3F7CHO and C4F9CHO are in good agreement with two recent determinations but the maximum value of the absorption cross section for CF3(CF2)5CH2CHO is over a factor of two lower than the single one recently published. The photolysis rates of C3F7CHO, C4F9CHO and CF3(CF2)5CHO have been measured under sunlight conditions in the EUPHORE simulation chamber in Valencia (Spain) at the beginning of June. The photolysis rates were, respectively, Jobs = (1.3 ± 0.6) × 10−5, (1.9 ± 0.8) × 10−5 and (0.6 ± 0.3) × 10−5 s−1. From the Jobs measurements and calculated photolysis rate Jcalc, assuming a quantum yield of unity across the atmospheric range of absorption of the aldehydes, quantum yields Jobs/Jcalc = (0.023 ± 0.012), (0.029 ± 0.015) and (0.046 ± 0.028) were derived for the photodissociation of C3F7CHO, C4F9CHO and CF3(CF2)5CHO, respectively. The atmospheric implication of the data obtained in this work is discussed. The main conclusion is that the major atmospheric removal pathway for fluoroaldehydes will be photolysis, which under low NOx conditions, may be a source of fluorinated carboxylic acids in the troposphere.
POLYCARBONATE-BASE POLYMER, PRODUCTION PROCESS, RESIN COATING FLUID PREPARED THEREFROM, AND ELECTROPHOTOGRAPHIC PHOTORECEPTOR PREPARED THEREFROM
申请人:IDEMITSU KOSAN COMPANY LIMITED
公开号:EP0837085A1
公开(公告)日:1998-04-22
A polymer comprising mainly repeating units (1) and/or repeating units (2), containing optionally terminal groups (3) and/or repeating units (4), and having a reduced viscosity [ηsp/c] of 0.2 to 10.0 dl/g as measured in a 0.5 g/dl solution thereof in methylene chloride at 20°C; a resin coating fluid containing the polymer, a charge-transfer substance and a solvent; and an electrophotographic photoreceptor containing the polymer as a binder resin in a photosensitive layer, wherein Rf1 represents a group that is composed of at least carbon atoms and fluorine atoms and bonded directly to the two oxygen atoms of the carbonate linkage in the general formula (1) without any intervening arylene group; and Rf2 represents a group that is composed of at least carbon atoms and fluorine atoms and bonded directly to one of the oxygen atoms of the carbonate linkage in the general formula (3) without any intervening arylene group.
Organofluorine compounds and fluorinating agents Part 17: Sonochemical-forced preparation of perfluoroalkanals and their use for non-conventional acetalations of carbohydrates
作者:Alexey O. Miller、Dietmar Peters、Cornelia Zur、Michael Frank、Ralf Miethchen
DOI:10.1016/s0022-1139(96)03551-8
日期:1997.4
The homologous 1-iodo-perfluoroalkanes 1a-1c and alpha,omega-dibromo-perfluoroalkanes 4a, 4b were carbonylated with DMF in the presence of Al/SnCl2 or Al/PbBr2 under sonication in a short reaction time. The hydrated aldehydes 2a-2c and 5a, 5b respectively were obtained in good yields allowing dehydration to 3a-3c and 6a, 6b. Some of the fluorinated aldehydes were selected as substrates in a Wittig-Homer olefination assisted by ultrasound and in non-conventional acetalations of methyl alpha-L-rhamnopyranoside (9). Thus, (E)-1-perfluorooctyl-2-phenylsulphonyl-ethene (8) was prepared from 3c and the phosphonate 7 by Wittig-Horner synthesis. Acetalations of 9 were carried out with the aldehydes (3a, 3b, 6a), hydrated aldehydes (2a, 2b), and the aldehyde hemiacetal 12 respectively, in the presence of dicyclohexylcarbodiimide (DCC). In all cases, a selective epimerization was observed at the C-atom 3 of the monosaccharide, i.e. polyfluoroalkylidenated 6-deoxy-alpha-L-altropyranosides 10, 11, 13, and 14 were obtained. (C) 1997 Elsevier Science S.A. All rights reserved.