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The IR transmittance spectrum of an isotopic mixture of chlorodifluoromethane (CHF2Cl, Ereon-22) with a 33% fraction of 13C and a natural ratio of chlorine isotopes was measured in the frequency range 1400–740 cm–1 with a resolution of 0.001 cm–1 at a temperature of 20°C. An ab initio calculation of the structure and sextic potential energy surface and surfaces of the components of the dipole moment has been carried out by the electronic quantum-mechanical method of Moller–Plesset, MP2/cc-pVTZ. Then the potential was optimized by replacing the harmonic frequencies with the frequencies calculated by the electronic method of coupled clusters, CCSD(T)/aug-cc-pVQZ. The fundamental and combination frequencies were calculated using the operator perturbation theory of Van Vleck (CVPTn) of the second and fourth order (n = 2, 4). Resonance effects were modeled using an additional variational calculation in the basis up to fourfold VCI excitation (4). The average prediction error for the fundamental frequencies of the 12C isotopologues was ~1.5 cm–1. The achieved accuracy made it possible to reliably predict the isotopic frequency shifts of the 13C isotopologues. It is shown that the strong Fermi resonance ν4/2ν6 dominates in the 12C isotopologues and is practically absent in 13C. The literature assumption [Spectrochim. Acta A, 44:553] about the splitting of ν1(CH) due to the resonance ν1/ν2 + ν7 + ν9 is confirmed. The coefficients of the polyadic quantum number are determined. The analysis made it possible to carry out a preliminary identification of the centers of the vibrational-rotational bands of isotopologues 13CHF235Cl and 13CHF237Cl in the spectrum of the mixture in preparation for individual analyzes of the vibrational-rotational structures of individual vibrational transitions. [ABSTRACT FROM AUTHOR]

Infrared laser conversion of chlorodifluoromethane (CF2HCl) enriched in 13C to 31%, to dibromodifluoromethane (CF2Br2) with the same enrichment has been studied. Optimum conditions have been found, and effective laser synthesis of macroscopic amounts (1 g) of CF2Br2 has been carried out. IR absorption spectra of synthesized CF2Br2 with a 13C concentration of 31% have been recorded. The 13C isotope shifts of the ν1, ν6, and ν8 modes have been measured. [ABSTRACT FROM AUTHOR]

The phase equilibrium behavior data are presented for three kinds of commercial polymer-bonded explosive (PBX) elastomers in chlorodifluoromethane (HCFC22). $$\hbox {Levapren}^{{\textregistered }}$$ ethylene- co-vinyl acetate (LP-EVA), $$\hbox {HyTemp}^{{\textregistered }}$$ alkyl acrylate copolymer (HT-ACM), and $$\hbox {Viton}^{{\textregistered }}$$ fluoroelastomer (VT-FE) were used as the PBX elastomers. For each elastomer + HCFC22 system, the cloud point (CP) and/or bubble point (BP) pressures were measured while varying the temperature and elastomer composition using a phase equilibrium apparatus fitted with a variable-volume view cell. The elastomers examined in this study indicated a lower critical solution temperature phase behavior in the HCFC22 solvent. LP-EVA showed the CPs at temperatures of 323 K to 343 K and at pressures of 3 MPa to 10 MPa, whereas HT-ACM showed the CPs at conditions between 338 K and 363 K and between 4 MPa and 12 MPa. For the LP-EVA and HT-ACM elastomers, the BP behavior was observed at temperatures below about 323 K. For the VT-FE + HCFC22 system, only the CP behavior was observed at temperatures between 323 K and 353 K and at pressures between 6 MPa and 21 MPa. As the elastomer composition increased, the CP pressure increased, reached a maximum value at a specific elastomer composition, and then remained almost constant. [ABSTRACT FROM AUTHOR]

Herein, we present the development of a continuous-flow process for a difluoromethylation with difluorocarbene as the reactive reagent. The difluoromethylated product is a key intermediate during the synthesis of eflornithine, a pharmaceutical that is on the World Health Organization's Model List of Essential Medicines. The developed procedure uses inexpensive and commercially available chlorodifluoromethane (CHF2Cl, Freon 22) as difluorocarbene source. Deprotonation of CHF2Cl with NaOH in a biphasic mixture of organic solvent-water generates the carbene. A fast subsequent reaction of the difluorocarbene with the substrate generates the desired product with excellent selectivity. [ABSTRACT FROM AUTHOR]

Butylene terephthalate cyclic (BTC) oligomers have been successfully polymerized to a poly(buthylene terephthalate) (PBT) employing the advantages of the low viscosity of cyclic oligomers and high solubility, high transport property of supercritical fluids. The ring-opening polymerization of BTC oligomers initiated by various mol concentration of catalyst (cyclic stannoxane 1) is carried out in supercritical chlorodifluoromethane (HCFC-22) at temperature ranging from 160 to 220 °C, at pressure ranging from 150 to 410 bar and at time ranging from 2 to 10 hrs. The highest molecular weight was obtained at 190 °C, 410 bar and 4 mol% mol concentration of catalyst. The results of XRD and TEM show that some of clays are intercalated or disordered, consisting of about 2–10 parallel silicate layers to form morphology like thin thread and some of clays are collapsed. The modulus and tensile strength of the nanocomposites prepared by supercritical process were higher than those of nanocomposites prepared by melt process. [ABSTRACT FROM AUTHOR]

Phase behavior data are presented for simvastatin, a water-insoluble drug, in supercritical solvent mixtures of chlorodifluoromethane (CHClF2) and carbon dioxide (CO2). The solubilities of the simvastatin drug in the solvent mixtures of CHClF2 and CO2 were determined by measuring the cloud point pressures using a variable-volume view cell apparatus as functions of temperature, solvent composition, and amount of the drug loaded into the solution. The cloud point pressure increased with increasing the system temperature. As the CHClF2 composition in the solvent mixture increased, the cloud point pressure at a fixed temperature decreased. Addition of CHClF2 to CO2 caused an increase of the dissolving power of the mixed solvent for the simvastatin drug due to the increase of the solvent polarity. CHClF2 acted as a solvent for simvastatin, while CO2 acted as an anti-solvent. The cloud point pressure increased as the amount of the simvastatin drug in the solvent mixture increased. Consequently, the solubility of the simvastatin drug in the solvent mixture of CHClF2 and CO2 decreased with increasing the CO2 content in the solvent mixture as well as with increasing the system temperature. [ABSTRACT FROM AUTHOR]

The adsorption of CHClF2 on NaY5.6 zeolite has been studied by measuring the H and F NMR of the adsorbed CHClF2, focusing in particular on the measurements of the chemical shift and longitudinal relaxation time, as well as the adsorption isotherm measurements. It is possible to determine the coordination structure of the CHClF2 adsorbed on NaY5.6 zeolite by measuring the adsorption amount dependence of the chemical shift. In addition, the motional activity of the adsorbed molecules in the super cage of the zeolite is discussed on the basis of observed longitudinal relaxation times for various adsorption amounts. [ABSTRACT FROM AUTHOR]

Two groups of three male volunteers were exposed to atmospheric concentrations of either 327 or 1833 mg m chlorodifluoromethane (HCFC22) for 4 h. Blood, urine and expired air samples were taken during and after the exposure period and analysed for HCFC22. Urine samples were also analysed for fluoride ion. During the exposure period, blood concentrations of HCFC22 approached a plateau, and the average peak blood concentrations of 0.25 and 1.36 μg cm were proportional to dose. HCFC22 concentrations in expired air were similar to the exposure concentration during the exposure period. The ratio between venous blood and breath concentrations of HCFC22 towards the end of the exposure period was on average 0.77, which is consistent with in vitro estimates of the partition coefficient. In the post-exposure period, three phases for the elimination of HCFC22 were identified, with estimated half-lives of 0.005, 0.2 and 2.6 h. HCFC22 was detected in urine samples taken in the post-exposure period, and the rate of decline was consistent with the terminal rate of elimination estimated from blood and breath measurements. On average 2.1% of the inhaled HCFC22 was recovered in breath within 26 h of exposure. This is consistent with the low solubility in blood and fat. Minimal changes in fluoride ion concentrations in urine following exposure indicate that HCFC22 is unlikely to be metabolised to a significant extent. Following inhalational exposure HCFC22 is poorly absorbed and is rapidly eliminated from the body. Possible biological monitoring strategies could be based on measurements of HCFC22 in urine or breath samples collected after the end of an exposure period. [ABSTRACT FROM AUTHOR]

The article presents a study on the thermal conductivity of the refrigerant R-406A in the vapor stage. It mentions that the refrigerant is a zeotrope mixture of isobutane, 1-difluoroethane and chlorodifluoromethane. It emphasizes that the thermal conductivity of the R0406A was specified through the method of using stationary coaxial cylinders. It also notes the increases of the thermal conductivity of the R-406A on the isotherms almost linearly with the pressure.

Inhalation pharmacokinetics of dichlorofluoromethane (CFC 21) and chlorodifluoromethane (CFC 22) were studied in male Wistar rats by use of a closed inhalation chamber system. CFC 21 was readily eliminated via metabolism. However, CFC 22 underwent no detectable metabolism; pretreatment of the rats with DDT or phenobarbital did not stimulate metabolic transformation of the compound. Hence, formation of biologically relevant amounts of reactive intermediates from CFC 22 as a mechanism of toxicity seems unlikely. [ABSTRACT FROM AUTHOR]