Freon mixture

In the methanol-Freon solvent mixture the methylmagnesium carbonate is only about twice as tolerant to water (as measured by the volume of water necessary to cause precipitation) as magnesium methoxide, but this appears to be sufficient to eliminate most, if not all, of the problems with water sensitivity. The difference in stability is apparently a result of the lower concentration of carbon dioxide in the methanol-Freon mixture since the Freon is a much poorer solvent for carbon dioxide than is methanol. 

Recently, a study of HB between adenosine and acetic acid at very low temperature has been published. The system was investigated using a deuterated freon mixture as the solvent (128 K). This experimental set-up made it possible to investigate the system in a slow-exchange regime using H NMR and 2D NOE experiments. 

A monotonous increase of the potential curve asymmetry is observed for complexes of carboxylic acids with collidine having in the freon mixture the ionic structure at 120-130 K. Here Vrn is about -65 Hz for acetic acid, 87 Hz for 2-nitrobenzoic acid and up to -90 and -92 Hz for HCl and HBF4 [82]. The... 

Isotope and solvent effects on fluxional hydrogen-bonded complexes of acetic acid and acetate have been studied by Limbach and co-workers. The spectra have been measured in the presence of tetra-n-butylammonium acetate around 110 K using liquefied Freon mixture as a solvent. Also spectra of the adduct CHs COOH SbCb have been recorded for comparison. For the first time, a two-bond coupling of the type JiCUsCOOH) between a hydrogen-bonded proton and the carboxylic carbon has been observed, Jhc = 3.0 Hz for comparison, the corresponding Jhc value in CHs COOH SbCb equals to 6.7 Hz. 

In the present study, we use freon mixture (FM mixture of CFCl and CFBr2CFBr2 in a 1 1 volume ratio) (J, 10) and 5ec-butyl chloride (sBuCl) for radical cation and MTHF for radical anion as matrices. Purification methods are the same as those described elsewhere (5,11,12). Potymethylpropylsilane (PMPrS) and Polymethylphenylsilane (PMPS) were synthesized according to the conventional method (i, 13). 

Since double diffusive convection is not unique to LNG or any other cryogenic liquid mixture, experimental rollover simulations have been studied with LA/LIN, LOX/LIN, and liquid Freon mixtures, as well as LNG mixtures. 

This chapter includes a number of advisory points on safety by flie auflior, from some 60 years of storing, handling and carrying out research on all kinds of cryogenic liquids, including LNGs, LPGs and Freon mixtures. 

With Freon 112 or 113 as a solvent, fluonnation of pnmary butyl halides with bromine trifluonde can give mixtures of primary and secondary fluorides When 1,4 dibromobutane is the substrate, 93% l-bromo-4-fluorobutane and 1% 1-bro-mo-3-fluorobutane is obtained, with 1,4 dichlorobutane, the product contains 65% l-chloro-3-fluorobutane and 35% 1-chloro 4 fluorobutane When 4-bromo- or 4-chlorobutyl trifluoroacetate is used, the ratio of 4-fluorobutyl tnfluoroacetate to 3 fluorobutyl trifluoroacetate is 1 4 The effect of solvent is measured in another set of experiments When the reaction of bromine trifluonde and l,3-dichloro-2-fluoropropane in either Freon 113 or hydrogen fluoride is allowed to proceed to 40% conversion, the product mixture has the composition shown m Table 1 [/O] When 1 chloro 2,3-dibromopropane is combined with one-third of a mole of bromine trifluonde, both 1 bromo 3 chloro-2-fluoropropane and l-chloro-2,3-di-fluoropropane are formed [//] (equation 10)... 

The formed mixture is composed of trichlorofluoromethane (Freon-11) and dichlorodifluoromethane (Freon-12). These compounds are used as aerosols and as refrigerants. Due to the depleting effect of chlorofluorocarbons (CFCs) on the ozone layer, the production of these compounds may be reduced appreciably. 

As discussed in Section 8.10, dediazoniation in methanol or ethanol yields mixtures of the corresponding aryl ethers and arenes, except with alcohols of very low nucleo-philicity such as trifluoroethanol, in which the aryl ether is the main product. Therefore aryl ethers are, in general, synthesized by alkylation of the respective phenol. Olah and Wu (1991) demonstrated, however, that phenylalkyl and aryl ethers can be obtained in 46-88% yield from benzenediazonium tetrafluoroborate using alkoxy- and phenoxytrimethylsilanes in solution in Freon 113 (l,l,2-trichloro-l,2,2-tri-fluoroethane) at 55-60 °C with ultrasonic irradiation. As seen from the stoichiometric... 

Introduction of F2 into 3,4,6-tri-O-acetyl-D-glucal (61) in CCI3F (Freon 11) at —78° in a manner used for the non-labeled compound (so-called cold synthesis) gave a 4 1 mixture of 3,4,6-tri-0-acetyl-2-deoxy-2-[ F]fluoro-a-D-gluco- (574) and ) -D-manno-pyranosyl fluorides (575),... 

Ethylene oxide gas is highly explosive in mixtures of >3.6% vN in air, in order to reduce this explosion hazard it is usually supplied for sterilization purposes as a 10% mix with carbon dioxide, or as an 8.6% mixture with HFC 124 (2 chloro-1,1,1,2 tetrafluoroethane) which has replaced fluorinated hydroearbons (freons). Alternatively, pure ethylene oxide gas can be used at below atmospheric pressure in sterihzer chambers from which all air has been removed. 

When used as a sterilizer for medical equipment, ethylene oxide has to be handled using concentrations in carbon dioxide or a freon that are lower than 10% (the mixture would combust in air). Bases catalyse the polymerisation. 

Solvent-assisted decaffeination of coffee can result in residues of solvent reaching the consumer.208 The use of chlorinated hydrocarbon solvents such as chloroform,209 methylene chloride, trichloroethylene,208 and difluoromonochloromethane (Freon),210 will probably be replaced by compounds already found in roasted coffee. The use of an ethyl acetate and 2-butanone mixture leaves a 26-ppm residue in green coffee, but zero residue in roasted coffee.211 Other solvent compounds used or suggested for coffee improvement or decaffeination include propane, butane,212 carbon dioxide,213 214 acetone215 dimethyl succinate,2161,1-dimethoxymethane, and 1,1-dimethoxyethane.217 Of all these, supercritical carbon dioxide, ethyl acetate, and methylene chloride are the solvents most used currently in decaffeination processes. 

To help soldiers keep their aircraft, barracks, tents, foxholes, and forest areas clear of malarial mosquitoes, the refrigeration industry and the U.S. Department of Agriculture developed an aerosol gun that sprayed a mixture of DDT, pyrethrum, and Thomas Midgley, Jr. s Freon 12 (Chapter 6). The insect bomb became so popular that it launched the postwar aerosol industry. 

The graphical correlation shown in Figure 5.30 was originally developed for a steam-water mixture of high quality. Coffield et al. (1967) extended its validity into the subcooled region by comparing their subcooled Freon-113 DNB data with... 

Grolmes, M. A., and H. K. Fauske, 1969, Propagation Characteristics of Compression and Rarefaction Pressure Pulses in One-Component Vapor-Liquid Mixtures, Nuclear Eng. Design 77 137-142. (3) Grolmes, M. A., and H. K. Fauske, 1970, Modeling of Sodium Expulsion of Freon-11, ASME Paper 70-HT-24, Fluids Engineering Heat Transfer and Lubrication Conf., Detroit, MI. (4)... 

Busche S., Dieterle F., Kieser B. and Gauglitz G., Quantification of binary mixtures of the freones R22 and R134a by surface plasmon resonance, Sensors Actuators B 2003 89 192-198. 

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