75-10-5 Difluoromethane

CFlBrClF (bromochlorofluoromethane) dipole moment, 99ff enantiomers, 79 symmetry elements, 79ff CF12F2 (difluoromethane) cartesian axes, 89 symmetry elements, 77, 83 CF13F (methyl fluoride) dipole moment, 116 symmetry elements, 74, 83 C Fl3F (methyl fluoride) vibration-rotation band, 178... 

Aromatic perfluoroaLkylation can be effected by fluorinated aUphatics via different techniques. One category features copper-assisted coupling of aryl hahdes with perfluoroalkyl iodides (eg, CF I) (111,112) or difluoromethane derivatives such as CF2Br2 (Burton s reagent) (113,114), as well as electrochemical trifluoromethylation using CF Br with a sacrificial copper anode (115). Extmsion of spacer groups attached to the fluoroalkyl moiety, eg,... 

Various bromofluoromethanes have been described and proposed for use as fire extinguishing agents (qv). Two that have been recommended highly for this purpose are dibromo difluoromethane [75-61-6] CBr2p2, and bromotrifluoromethane [75-65-8], CBrF, (94). Bromochlorodifluoromethane [353-59-3], CBrClF2, is another fire extinguishing agent. These and similar substituted methanes are potentially useful for the synthesis of other halo—fluoro compounds. 

I iL-un 12 (CCljFj) which is now banned by the ozone protection treaty. Also used is Dichloro-difluoromethane, Freon 22 (CHClFj), and chloro-difluoromethane. Several analogous compounds containing carbon, fluorine, chlorine, and sometimes hydrogen are available. 

Diethyl aniline, 54 Diethylcarbaniazine citrate, 54 Diethyl carbamyl chloride, 54 Diethyl chlorophosphate, 54 Diethylene triamine, 54 Diethyl ether, 54 Di(2-ethylhexyl) phthalate, 54 Diethyl ketone, 54 Diethyl-p-phenylenediamine, 54 Diethyl phthalate, 54 Diethylstilbestrol, 55 Diethyl sulfate, 55 Diethyl zinc, 55 Difluoromethane chloride, 55 Digitoxin, 55 Diglycidyl ether, 55 Digoxin, 55 Diisobutyl ketone, 55 Diisopropylamine, 55 Diisopropyl ether, 55 DIKAMIN , 2,4-D, 55 DIKONIRT , 2,4-D, 55 Dimefox, 55 Dimethoate, 55 3,3 -Dimethoxybenzidine, 55 n,n-Dimethylacetamide, 56 Dimethylamine, 56 4-Dimethylaminoazobenzene, 56 Dimethylaminoethanol, 56 n,n-Dimethyl aniline, 56 7,12-Dimethylbenz[a]anthracene, 56 3,3 -Dimethylbenzidine, 56... 

Difluoromethane Chlorodifluoro- Azeotrope Pentafluoroethane Chlorodifluoro- Azeotrope... 

Flnoromethane has been nsed as a selective inhibitor of ammoninm oxidation and nitrification-linked synthesis of N2O in Nitrosomonas europaea (Miller et al.l993), while difluoromethane has been proposed as a reversible inhibitor of methanotrophs (Miller et al. 1998). 

Both homotopic fluorines such as those in difluoromethane and 2,2-difluoropropane and 1,1-difluoroethene, and enantiotopic fluorines such as those in chlorodifluoromethane and 2,2-difluorobutane (Scheme 2.8) would be chemically equivalent. 

The CF2 group exhibits a wide range of chemical shift possibilities, with, for example, difluoromethane compounds appearing at both... 

Horstmann, S., Wilken, M., Fischer, K., Gmehling, J. (2004) Isothermal vapor-liquid equilibrium and excess enthalpy data for the binary systems propylene oxide + 2-methylpentane and difluoromethane (R32) + pentafluoroethane (R125). J. Chem. Eng. Data 49,1504-1507. 

We first consider pi nonbonded interactions in difluoromethane and employ the dissection shown below. The appropriate interaction diagram for the pi system only is shown in Fig. 13. From this diagram it is obvious that only the symmetric... 

The problems facing the static model can be best understood by reference to the various computed indices for difluoromethane at various FCF angles. Comparing the two structures shown above, we note that the total pi overlap population increases as the angle shrinks. Thus, according to the dynamic model, there is F—F pi nonbonded attraction since the difference in the total pi overlap populations is... 

The angle problem in 1,1-difluoroethylene can be treated in a similar manner. The pi nonbonded interaction between the F2pz lone pairs is identical to that encountered in the case of difluoromethane due to the fact that 1,1-difluoroethylene and difluoromethane are pi isoconjugate. A confirmation of our analysis is provided by the results of computations shown above. 

Critical points vary widely. Table 6.1 shows a representative sample of critical parameters and it is immediately obvious why carbon dioxide is widely used. With a critical temperature just above room temperature and a critical pressure that is relatively low, the amount of energy needed to render carbon dioxide supercritical is comparatively small. Fluoroform (CHF3) and difluoromethane also have easily attainable critical parameters, but they are much more expensive than carbon dioxide. Despite its high critical temperature and pressure, supercritical water (SCH2O) is used widely as a destructive medium since it is highly acidic. 

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