Theoretical studies on the reactions CH3SCH3 with OH,CF3, and CH3 radicals

The multiple‐channel reactions OH + CH₃SCH₃ → products, CF₃ + CH₃SCH₃ → products, and CH₃ + CH₃SCH₃ → products are investigated by direct dynamics method. The optimized geometries, frequencies, and minimum energy path are all obtained at the MP2/6‐31+G(d,p) level, and energetic information is further refined by the MC‐QCISD (single‐point) method. The rate constants for eight reaction channels are calculated by the improved canonical variational transition state theory with small‐curvature tunneling contribution over the temperature range 200–3000 K. The total rate constants are in good agreement with the available experimental data and the three‐parameter expressions k₁ = 4.73 × 10^?16T^1.89 exp(?662.45/T), k₂ = 1.02 × 10^?32T^6.04 exp(933.36/T), k₃ = 3.98 × 10^?35T^6.60 exp(660.58/T) (in unit of cm³ molecule^?1 s^?1) over the temperature range of 200–3000 K are given. Our calculations indicate that hydrogen abstraction channels are the major channels and the others are minor channels over the whole temperature range. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010     

EPR kinetic study of the reactions of CF3Br with H atoms and OH radicals

Reactions of CF₃Br with H atoms and OH radicals have been studied at room temperature at 1–2 torr pressures in a discharge flow reactor coupled to an EPR spectrometer. The rate constant of the reaction H + CF₃Br → CF₃ + HBr (1) was found to be k₁ = (3.27 ± 0.34) × 10^?14 cm³/molec·sec. For the reaction of OH with CF₃Br (8) an upper limit of 1 × 10^?15 cm³/molec·sec was determined for k₈. When H atoms were in excess compared to NO₂, used to produce OH radicals, a noticeable reactivity of OH was observed as a result of the reaction OH + HBr → H₂O + Br, HBr being produced from reaction (1).     

Theoretical studies of the reactions of CF3CHCLOCHF2/CF3CHFOCHF2 with OH radical and Cl atom and their product radicals with OH

The mechanisms and dynamics studies of the OH radical and Cl atom with CF(3)CHClOCHF(2) and CF(3)CHFOCHF(2) have been carried out theoretically. The geometries and frequencies of all the stationary points are optimized at the B3LYP/6-311G(d,p) level, and the energy profiles are further refined by interpolated single-point energies (ISPE) method at the G3(MP2) level of theory. For each reaction, two H-abstraction channels are found and four products (CF(3)CHFOCF(2), CF(3)CFOCHF(2), and CF(3)CHClOCF(2), CF(3)CClOCHF(2)) are produced during the above processes. The rate constants for the CF(3)CHClOCHF(2)/CF(3)CHFOCHF(2) + OH/Cl reactions are calculated by canonical variational transition-state theory (CVT) within 200-2000 K, and the small-curvature tunneling is included. The total rate constants calculated from the sum of the individual rate constants and the branching ratios are in good agreement with the experimental data. The Arrhenius expressions for the reactions are obtained. Our calculation shows that the substitution of Cl by F decreases the reactivity of CF(3)CHClOCHF(2) toward OH and Cl. In addition, the mechanisms of subsequent reactions of product radicals and OH radical are further investigated at the G3(MP2)//B3LYP/6-311G(d,p) level, and the main products are predicted in the this article.     

Hydrogen abstraction from CF3CF2CFH2 and CF3CFHCF2H by OH radicals and Cl atoms: theoretical enthalpies and rate constants

The hydrogen abstraction reactions of CF₃CF₂CFH₂ and CF₃CFHCF₂H with OH radicals and Cl atoms have been studied theoretically by a dual-level direct dynamics method. Two stable conformers of CF₃CF₂CFH₂ with C _s and C ₁ symmetries and all possible abstraction channels for each reaction are all taken into consideration. Optimized geometries and frequencies of all the stationary points and extra points along minimum-energy path (MEP) have been computed at the BB1K/6-31+G(d, p) level of theory. To refine the energy profile of each reaction channel, single point energy calculations have been performed by the BMC-CCSD method. The rate constants are evaluated by canonical variational transition state theory (CVT) with the small-curvature tunneling correction method (SCT) over a wide temperature range of 200–1,000 K. The detailed branching ratios of four reactions are discussed. The good agreement found between our theoretical rate constants and the available experimental data suggests that the present approach could provide a reliable prediction for the CF₃CFHCF₂H + Cl reaction about which there is little experimental information. The kinetic calculations show that the SCT effect plays an important role in all channels. In addition, in order to further reveal the thermodynamic properties, the enthalpies of formation of the reactants (CF₃CF₂CFH₂ and CF₃CFHCF₂H) and the product radicals (CF₃CF₂CFH, CF₃CFCF₂H, and CF₃CFHCF₂) are evaluated by applying isodesmic reactions at both BMC-CCSD//BB1K/6-31+G(d, p) and MC-QCISD//BB1K/6-31+G(d, p) levels of theory.     

Kinetics and mechanisms of CF3CHFOCH3, CF3CHFOC(O)H, and FC(O)OCH3 reactions with OH radicals

The kinetics and mechanism of oxidation of CF3CHFOCH3 was studied using an 11.5-dm3 environmental reaction chamber. OH radicals were produced by UV photolysis of an O3-H2O-He mixture at an initial pressure of 200 Torr in the chamber. The rate constant of the reaction of CF3CHFOCH3 with OH radicals (k1) was determined to be (1.77 +/- 0.69) x 10(-12) exp[(-720 +/- 110)/T] cm3 molecule(-1)(s-1) by means of a relative rate method at 253-328 K. The mechanism of the reaction was investigated by FT-IR spectroscopy at 298 K. CF3CHFOC(O)H, FC(O)OCH3, and COF2 were determined to be the major products. The branching ratio (k1a/k1b) for the reactions CF3CHFOCH3 + OH --> CF3CHFOCH2* + H2O (k1a) and CF3CHFOCH3 + OH --> CF3CF*OCH3 + H2O (k1b) was estimated to be 4.2:1 at 298 K from the yields of CF3CHFOC(O)H, FC(O)OCH3, and COF2. The rate constants of the reactions of CF3CHFOC(O)H (k2) and FC(O)OCH3 (k3) with OH radicals were determined to be (9.14 +/- 2.78) x 10(-13) exp[(-1190 +/- 90)/T] and (2.10 +/- 0.65) x 10(-13) exp[(-630 +/- 90)/T] cm3 molecule(-1)(s-1), respectively, by means of a relative rate method at 253-328 K. The rate constants at 298 K were as follows: k1 = (1.56 +/- 0.06) x 10-13, k2 = (1.67 +/- 0.05) x 10-14, and k3 = (2.53 +/- 0.07) x 10-14 cm3 molecule(-1)(s-1). The tropospheric lifetimes of CF3CHFOCH3, CF3CHFOC(O)H, and FC(O)OCH3 with respect to reaction with OH radicals were estimated to be 0.29, 3.2, and 1.8 years, respectively.     

Long path-FTIR studies of some atmospheric reactions involving CF3OO and CF3O radicals

In attempts to obtain kinetic and mechanistic data required for an assessment of atmospheric fate of alternative halocarbons containing a CF₃ group, reactions of the key free radical intermediates CF₃OO and CF₃O with several atmospheric compounds (i.e., NO, NO₂, alkanes and alkenes) have been studied at 297 ± 2 K in 700 torr of air. Experiments employed the long path-FTIR spectroscopic method for product analysis and the visible (400 nm) photolysis of CF₃NO → CF₃ + NO as a source for the precursor radical CF₃. Numerous labile and stable F-containing molecular products have been characterized based on kinetic and spectroscopic data obtained at sufficiently short photolysis time (≤1 min) to minimize heterogeneous decay on the reactor walls. Major new findings have been made for the reactions involving CF₃O radicals. The behavior of CF₃O radicals has been shown to be markedly different from that of CH₃O radicals, i.e., (1) O₂-reaction: no evidence for the F-atom transfer reaction CF₃O + O₂ → CF₂ O + FOO; (2) NO-reaction: addition reaction CH₃O + NO (+M) → CH₃ONO (+M), but F-transfer reaction CF₃O + NO → CF₂O + FNO; (3) NO₂-reaction: addition reaction for both radicals, but F-transfer reaction CF₃ + NO₂ → CF₂O + FNO₂ to a minor extent; (4) alkane-reaction: much faster H-abstraction by CF₃O, comparable to HO; (5) alkene-reaction: much faster addition reaction of CF₃O, comparable to HO. These results are summarized in this paper.     

The reactions of CF3 radicals with cyclanes and the determination of C?H bond dissociation energies in cyclanes

The reactions of CF₃ radicals with the C₃ to C₇ cyclanes and spiropentane were studied and the following Arrhenius parameters were obtained for the reaction CF₃ + c-RH → CF₃H + c-R:

Rate constants for the reactions of OH radicals with CH3OCF2CF3, CH3OCF2CF2CF3, and CH3OCF(CF3)2

The rate constants for the reactions of OH radicals with CH₃OCF₂CF₃, CH₃OCF₂CF₂CF₃, and CH₃OCF(CF₃)₂ have been measured over the temperature range 250–430 K. Kinetic measurements have been carried out using the flash photolysis, laser photolysis, and discharge flow methods combined respectively with the laser induced fluorescence technique. The influence of impurities in the samples was investigated by using gas‐chromatography. The following Arrhenius expressions were determined: k(CH₃OCF₂CF₃) = (1.90) × 10⁻¹² exp[−(1510 ± 120)/T], k(CH₃OCF₂CF₂CF₃) = (2.06) × 10⁻¹² exp[−(1540 ± 80)/T], and k(CH₃OCF(CF₃)₂) = (1.94) × 10⁻¹² exp[−(1450 ± 70)/T] cm³ molecule⁻¹ s⁻¹. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 846–853, 1999     

The reactions of CF3 and CD3 radicals with boron trimethyl

Hydrogen abstraction from boron trimethyl has been studied using the abstracting radicals CF₃ and CD₃, from the photolysis of the corresponding ketones over the temperature range of 150° to 300°C. The following Arrhenius parameters were obtained: The difference E – E in the case of BMe₃ is considered due, in part, to polar effects. An exchange reaction is proposed for both CF₃ and CD₃ in collisions with BMe₃: Radical combination of CF₃ and CH₂BMe₂ leads to a hot molecule which undergoes a β-fluoro rearrangement elimination process, or a stabilized molecule which can thermally decompose:      

Reaction of CF3 radicals with H2S

Hydrogen abstration from H₂S by CF₃ radicals, generated by the photolysis of both CF₃COCF₃ and CF₃I, has been studied in the temperature range 314–434 K. The rate constant, based on the value of 10^13.36 cm³/mol · s for the recombination of CF₃ radicals, is given by with CF₃COCF₃ as the radical source, and with CF₃I as the radical source, where k₂ is in cm³/mol · s and E is in J/mol. These results resolve a previously existing controversy concerning the values of the rate constants for this reaction. They show that CF₃ radicals are less reactive than CH₃ radicals in attacking H₂S, and this behavior indicates that polar effects play a significant role in the hydrogen transfer reactions of CF₃ radicals.     

Kinetic study of the reactions of Cl atoms with CF3CH2CH2OH, CF3CF2CH2OH, CHF2CF2CH2OH, and CF3CHFCF2CH2OH

The reaction kinetics of chlorine atoms with a series of partially fluorinated straight-chain alcohols, CF(3)CH(2)CH(2)OH (1), CF(3)CF(2)CH(2)OH (2), CHF(2)CF(2)CH(2)OH (3), and CF(3)CHFCF(2)CH(2)OH (4), were studied in the gas phase over the temperature range of 273-363 K by using very low-pressure reactor mass spectrometry. The absolute rate coefficients were given by the expressions (in cm(3) molecule(-1) s(-1)): k(1) = (4.42 +/- 0.48) x 10(-11) exp(-255 +/- 20/T); k(1)(303) = (1.90 +/- 0.17) x 10(-11), k(2) = (2.23 +/- 0.31) x 10(-11) exp(-1065 +/- 106/ T); k(2)(303) = (6.78 +/- 0.63) x 10(-13), k(3) = (8.51 +/- 0.62) x 10(-12) exp(-681 +/- 72/T); k(3)(303) = (9.00 +/- 0.82) x 10(-13) and k(4) = (6.18 +/- 0.84) x 10(-12) exp(-736 +/- 42/T); k(4)(303) = (5.36 +/- 0.51) x 10(-13). The quoted 2sigma uncertainties include the systematic errors. All title reactions proceed via a hydrogen atom metathesis mechanism leading to HCl. Moreover, the oxidation of the primarily produced radicals was investigated, and the end products were the corresponding aldehydes (R(F)-CHO; R(F) = -CH(2)CF(3), -CF(2)CF(3), -CF(2)CHF(2), and -CF(2)CHFCF(3)), providing a strong experimental indication that the primary reactions proceed mainly via the abstraction of a methylenic hydrogen adjacent to a hydroxyl group. Finally, the bond strengths and ionization potentials for the title compounds were determined by density functional theory calculations, which also suggest that the alpha-methylenic hydrogen is mainly under abstraction by Cl atoms. The correlation of room-temperature rate coefficients with ionization potentials for a set of 27 molecules, comprising fluorinated C2-C5 ethers and C2-C4 alcohols, is good with an average deviation of a factor of 2, and is given by the expression log(k) (in cm(3) molecule(-1) s(-1)) = (5.8 +/- 1.4) - (1.56 +/- 0.13) x (ionization potential (in eV)).     

Reflected shock tube and theoretical studies of high-temperature rate constants for OH+CF3H<-->CF3+H2O and CF3+OH-->products

The reflected shock tube technique with multipass absorption spectrometric detection of OH radicals at 308 nm, using either 36 or 60 optical passes corresponding to total path lengths of 3.25 or 5.25 m, respectively, has been used to study the bimolecular reactions, OH+CF3H-->CF3+H2O (1) and CF3+H2O-->OH+CF3H (-1), between 995 and 1663 K. During the course of the study, estimates of rate constants for CF3+OH-->products (2) could also be determined. Experiments on reaction -1 were transformed through equilibrium constants to k1, giving the Arrhenius expression k1=(9.7+/-2.1)x10(-12) exp(-4398+/-275K/T) cm3 molecule(-1) s(-1). Over the temperature range, 1318-1663 K, the results for reaction 2 were constant at k2=(1.5+/-0.4)x10(-11) cm3 molecule(-1) s(-1). Reactions 1 and -1 were also studied with variational transition state theory (VTST) employing QCISD(T) properties for the transition state. These a priori VTST predictions were in good agreement with the present experimental results but were too low at the lower temperatures of earlier experiments, suggesting that either the barrier height was overestimated by about 1.3 kcal/mol or that the effect of tunneling was greatly underestimated. The present experimental results have been combined with the most accurate earlier studies to derive an evaluation over the extended temperature range of 252-1663 K. The three parameter expression k1=2.08x10(-17) T1.5513 exp(-1848 K/T) cm3 molecule(-1) s(-1) describes the rate behavior over this temperature range. Alternatively, the expression k1,th=1.78x10(-23) T3.406 exp(-837 K/T) cm3 molecule(-1) s(-1) obtained from empirically adjusted VTST calculations over the 250-2250 K range agrees with the experimental evaluation to within a factor of 1.6. Reaction 2 was also studied with direct CASPT2 variable reaction coordinate transition state theory. The resulting predictions for the capture rate are found to be in good agreement with the mean of the experimental results and can be represented by the expression k2,th=2.42x10(-11) T-0.0650 exp(134 K/T) cm3 molecule(-1) s(-1) over the 200-2500 K temperature range. The products of this reaction are predicted to be CF2O+HF.     

Kinetics and mechanism of (CF3)2CHOCH3 reaction with OH radicals in an environmental reaction chamber

The atmospheric chemistry of (CF3)2CHOCH3, a possible HCFC/HFC alternative, was studied using a smog chamber/FT-IR technique. OH radicals were prepared by the photolysis of ozone in a 200-Torr H2O/O3/O2 gas mixture held in an 11.5-dm3 temperature-controlled chamber. The rate constant, k1, for the reaction of (CF3)2CHOCH3 with OH radicals was determined to be (1.40 +/- 0.28) x 10(-12) exp[(-550 +/- 60)/T] cm3 molecule(-1) s(-1) by means of a relative rate method at 253-328 K. The value of k1 at 298 K was (2.25 +/- 0.04) x 10(-13) cm3 molecule(-1) s(-1). The random errors are reported with +/-2 standard deviations, and potential systematic errors of 15% could increase k(1). In considering OH-radical reactions, we estimated the tropospheric lifetime of (CF3)2CHOCH3 to be 2.0 months using the rate constant at 288 K. The degradation mechanism of (CF3)2CHOCH3 initiated by OH radicals was also investigated using FT-IR spectroscopy at 298 K. Products (CF3)2CHOC(O)H, CF3C(OH)2CF3, CF3C(O)OCH3, and COF(2) were identified and quantified. The branching ratio, k1a/k1b, was estimated to be 2.1:1 for reactions (CF3)2CHOCH3 + OH --> (CF3)2CHOCH2*+ H2O (k1a) and (CF3)2CHOCH3 + OH --> (CF3)2C*OCH3 + H2O (k1b).     

SF_5CF_3与还原性自由基C_2H_3脱氟反应机理研究

用密度泛函B3PW91/6-311g(d,p)方法对SF5CF3与还原性自由基C2H3反应机理进行了理论研究,优化了反应通道上反应物、过渡态、中间体和产物的几何构型,用内禀反应坐标计算和频率分析确认了过渡态.用精确模型算法G3(MP2)计算了各物种单点能量.研究结果表明:SF5CF3与C2H3自由基反应为多通道反应,C2H3可脱去SF5CF3分子中不同位上的F原子,分别生成3个中间体IM1,IM2和IM3.然后3个中间体发生自分解反应生成产物P1[CF2SF5+C2H3F],P2[CF3SF4(a)+C2H3F]和P3[CF3SF4(b)+C2H3F],其中Path 2和Path 3能垒高度分别为141.9和147.0kJ·mol-1,为竞争反应通道,P2和P3为反应主产物.     

Some hydrogen atom abstraction reactions of CF2H and CFH2 radicals,and the C?H bond dissociation energy in CF2H2

By photolyzing (CF₂H)₂CO and (CFH₂)₂CO the hydrogen atom abstraction reactions of CF₂H radicals with (CF₂H)₂CO, H₂, D₂, CH₄, C₂H₆, n? C₄H₁₀ and iso? C₄H₁₀, and the reactions of CFH₂ radicals with (CFH₂)₂CO and n? C₄H₁₀, have been studied. Arrhenius parameters for these reactions are compared with related systems. From a knowledge of the activation energies for the forward and reverse reactions a value of the bond dissociation energy, D(CF₂H? H) = 97.4 ± 1.3 kcal mole^?1 at a mean temperature of 543°K is obtained. This value is subject to much uncertainty due to possible compensation effects in the Arrhenius parameters. These effects are discussed for this and the other reactions, and the data suggest that D(CF₂H? H) is approximately 100 kcal mole^?1, and that D(CFH₂? H) is very similar. Other literature data tend to confirm these approximate values.     

Kinetics of the gas‐phase reaction of CF3CF2CH2OH with OH radicals and its atmospheric lifetime

CF₃CF₂CH₂OH is a new chlorofluorocarbon (CFC) alternative. However, there are few data about its atmospheric fate. The kinetics of its atmospheric oxidation, the OH radical reaction of CF₃CF₂CH₂OH, has been investigated in a 2‐liter Pyrex reactor in the temperature range of 298 ∼ 356 K using gas chromatography (GC)–mass spectrometry (MS) for analysis in this study. The rate coefficient of k₁ = (2.27) × 10⁻¹² exp[−(900 ± 70)/T] cm³ molecule⁻¹ s⁻¹ was determined using the relative rate method. The results are in good agreement with the literature values and the prediction of Atkinson's structure–activity relationship (SAR) model. From these results, the atmospheric lifetime of CF₃CF₂CH₂OH in the troposphere was deduced to be 0.34 year, which is 250 and 6 times shorter than those of CFC‐113 and hydrochlorofluorocarbons (HCFC‐225ca), respectively. Therefore CF₃CF₂CH₂OH has significant potential for the replacement of CFC‐113 and HCFC‐225ca. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 73–78, 2000     

Reaction of CF3 radicals with C2H6

The hydrogen transfer reaction between C₂H₆ and CF₃ radicals, generated by the photolysis of CF₃I, has been studied in the temperature range 298–617 K. The rate constant, based on the value of 10^13.36 cm³ mol^?1 s^?1 for the recombination of CF₃ radicals, is given by where k₂ is in cm³ mol^?1 s^?1 and E is in J mol^?1. These results are compared with those previously reported, and the following best value for k₂ is recommended:      

Atmospheric chemistry of CF3OCF2CF2H and CF3OC(CF3)2H: reaction with Cl atoms and OH radicals, degradation mechanism, global warming potentials, and empirical relationship between k(OH) and k(Cl) for organic compounds

Using FTIR smog chamber techniques, k(Cl + CF3OCF2CF2H) = (2.70 +/- 0.52) x 10(-16), k(OH + CF3OCF2CF2H) = (2.26 +/- 0.18) x 10(-15), k(Cl + CF3OC(CF3)2H) = (1.58 +/- 0.27) x 10(-18) and k(OH + CF3OC(CF3)2H) = (3.26 +/- 0.95) x 10(-16) cm3 molecule(-1) s(-1) were measured. The atmospheric lifetimes of CF3OCF2CF2H and CF3OC(CF3)2H are estimated to be 27 and 216 years, respectively. Chlorine atom initiated oxidation of CF3OCF2CF2H in 700 Torr of air in the presence of NO(x) gives CF3OC(O)F in a molar yield of 36 +/- 5% and COF2 in a molar yield of 174 +/- 9%, whereas oxidation of CF3OC(CF3)2H gives CF3OC(O)CF3 and COF2 in molar yields that are indistinguishable from 100%. Quantitative infrared spectra were recorded and used to estimate global warming potentials of 3690 and 8230 (100 year time horizon, relative to CO2) for CF3OCF2CF2H and CF3OC(CF3)2H, respectively. All experiments were performed in 700 Torr of N2/O2 diluent at 296 +/- 2 K. An empirical relationship can be used to estimate the preexponential factor, which can be combined with k(298 K) to give the temperature dependence of reactions of OH radicals with organic compounds proceeding via H-atom abstraction: log(A/n) = (0.239 +/- 0.027) log(k(OH)/n) - (8.69 +/- 0.372), k(OH) is the rate constant at 298 K and n is the number of H atoms. The rates of H-atom abstraction by OH radicals and Cl atoms at 298 K from organic compounds are related by the expression log(k(OH)) = (0.412 +/- 0.049) log(k(Cl)) - (8.16 +/- 0.72). The utility of these expressions and the atmospheric chemistry of the title hydrofluoroethers are discussed.     

Atmospheric chemistry of CCl2FCH2CF3 (HCFC-234fb): Kinetics and mechanism of reactions with Cl atoms and OH radicals

The atmospheric chemistry of CCl₂FCH₂CF₃ (HFCF-234fb) was examined using FT-IR/relative-rate methods. Hydroxyl radical and chlorine atom rate coefficients of k(CCl₂FCH₂CF₃+OH)= (2.9 ± 0.8) × 10⁻¹⁵ cm³ molecule^–1 s^–1 and k(CCl₂FCH₂CF₃+Cl)= (2.3 ± 0.6) × 10⁻¹⁷ cm³ molecule^–1 s^–1 were determined at 297 ± 2 K. The OH rate coefficient determined here is two times higher than the previous literature value. The atmospheric lifetime for CCl₂FCH₂CF₃ with respect to reaction with OH radicals is approximately 21 years using the OH rate coefficient determined in this work, estimated Arrhenius parameters and scaling it to the atmospheric lifetime of CH₃CCl₃. The chlorine atom initiated oxidation of CCl₂FCH₂CF₃ gives C(O)F₂ and C(O)ClF as stable secondary products. The halogenated carbon balance is close to 80% in our system. The integrated IR absorption cross-section for CCl₂FCH₂CF₃ is 1.87 × 10⁻¹⁶ cm molecule⁻¹ (600–1600 cm⁻¹) and the radiative efficiency was calculated to 0.26 W m⁻² ppb¹. A 100-year Global Warming Potential (GWP) of 1460 was determined, accounting for an estimated stratospheric lifetime of 58 years and using a lifetime-corrected radiative efficiency estimation.     

The complexes between CH3OH and CF4. Infrared matrix isolation and theoretical studies

The complex formed between methanol and tetrafluoromethane has been identified in argon and neon matrixes by help of FTIR spectroscopy. Three fundamentals (nu(OH), nu(FCF), and nu(CO)) were observed for the complex isolated in the two matrixes, and the OH stretch was red shifted in a neon matrix and blue shifted in an argon matrix with respect to the corresponding vibration of the methanol monomer. The theoretical studies of the structure and spectral characteristics of the complexes formed between CH(3)OH and CF(4) were carried out at the MP2 level of theory with the 6-311+G(2df,2pd) basis set. The calculations resulted in three stationary points from which two (I-1, I-2) corresponded to structures involving the O-H...F hydrogen bond and the third one (I-3) to the non-hydrogen-bonded structure. The topological analysis of the distribution of the charge density (AIM theory) confirmed the existence of the hydrogen bond in I-1, I-2 complexes and indicated weak interaction between the oxygen atom of CH(3)OH and three fluorine atoms of CF(4) in the I-3 complex. The comparison of the experimental and theoretical data suggests that in the matrixes only the non-hydrogen-bonded complex I-3 is trapped. The blue/red shift of the complex OH stretching vibration with respect to the corresponding vibration of CH(3)OH in argon/neon matrixes is explained by the different sensitivity of the complex and monomer vibrations to matrix material. The ab initio calculations performed for the ternary CH(3)OH-CF(4)-Ar systems indicated a negligible effect of an argon atom on the binary complex frequencies.