Über die Gasphasenstruktur von CF3NCl2 und die Darstellung von CF3NCl2F+MF6− (M = As,Sb) und CF2 = NClF+SbF6−

Gas Phase Structure of CF₃NCl₂ and Preparation of CF₃NCl₂F⁺MF₆^? (M = As, Sb) and CF₂ = NCl₂F⁺SbF₆^? The gas phase structure of CF₃NCl₂ is reported. The following skeletal parameters are derived (r_a-values, error limits are 3σ values): N? C = 1.470(6) Å, N? Cl = 1.733(3) Å, ClNCl = 111.5(4)° and ClNC = 107.6(5)°. CF₃NCl₂F⁺MF₆^? is prepared by fluorination of CF₃NCl₂ with XeF⁺MF₆^?. The same educt CF₃NCl₂ reacts with XeF⁺SbF₆^? at ?40°C to CF₂ = NClF⁺SbF₆^? under elimination of ClF.     

C,N-chelated organotin(IV) trifluoroacetates. Instability of the mono- and diorganotin(IV) derivatives.

The C,N-chelated tri-, di- and monoorganotin(IV) halides react with equimolar amounts of CF₃COOAg to give corresponding C,N-chelated organotin(IV) trifluoroacetates. The set of prepared tri-, di- and monoorganotin(IV) trifluoroacetates bearing the L^CN ligand (where L^CN is 2-(N,N-dimethylaminomethyl)phenyl-) was structurally characterized by X-ray diffraction analyses, multinuclear NMR and IR spectroscopy. In the case of triorganotin(IV) trifluoroacetates and (L^CN)₂Sn(OC(O)CF₃)₂, no tendency to form hydrolytic products, or instability towards the moisture was observed. L^CNRSn(OC(O)CF₃)₂ (where R is n-Bu or Ph) and L^CNSn(OC(O)CF₃)₃ forms upon crystallization from THF in the air mainly dinuclear complexes in which the two tin atoms are interconnected either by hydroxo-bridges or by an oxo-bridge and/or by a bridging trifluoroacetate(s). In the case of hydrolysis of L^CN(n-Bu)Sn(OC(O)CF₃)₂, a zwitterionic stannate of formula L^CN(n-Bu)Sn(OC(O)CF₃)₂·CF₃COOH was isolated from the mother liquor, too. Products of hydrolysis of L^CN(n-Bu)Sn(OC(O)CF₃)₂ and L^CNSn(OC(O)CF₃)₃, and some other oxygen bridged organotin(IV) compounds containing the same ligand, were tested as possible catalysts of some transesterification reactions as well as in direct dimethyl carbonate (DMC) synthesis from CO₂ and methanol.     

Unimolecular Rate Constants for the HF and HCl Elimination Reactions from Chemically Activated CF2ClSH

Chemically activated CF₃SH, CFCl₂SH, and CF₂ClSH were formed through combination of SH and CF₃, CFCl₂, and CF₂Cl radicals, respectively. The SH radical was prepared by abstraction of an H‐atom from H₂S by the halocarbon radical produced during photolysis of (CF₃)₂C=O, (CFCl₂)₂C=O, or (CF₂Cl)₂C=O. 1,2‐HX (X = F, Cl) elimination reactions were observed from CF₃SH, CFCl₂SH, and CF₂ClSH with products detected by GC‐MS. The combination reaction of CF₂Cl radicals with SH radicals prepared CF₂ClSH molecules with approximately 318 kJ/mol of internal energy. The experimental rate constants for elimination of HCl and HF from CF₂ClSH were 3 ± 3 × 10¹⁰ and 2 ± 1 × 10⁹ s^?1, respectively. Comparison to Rice–Ramsperger–Kassel–Marcus (RRKM) calculated rate constants assigned the threshold energies as 171 ± 12 and 205 ± 12 kJ/mol for the unimolecular elimination of HCl and HF, respectively. Theoretical calculations using the B3PW91, MP2, and M062X methods with the 6311+G(2d,p) and 6‐31G(d',p') basis sets established that for a specific method the threshold energies differ by only 4 kJ/mol between the two different basis sets. There was wide variation among the three methods, but the M062X approach appeared to give threshold energies closest to the experimental values. Chemically activated CF₃SH and CFCl₂SH were also prepared with about 318 kcal mol^?1 of internal energy, and the HX (X = F, Cl) elimination reactions were observed. Only HCl loss was detected from CFCl₂SH, but the rate was too fast to measure with our kinetic method; however, based on our detection limit the HF elimination channel is at least 50 times slower.     

Reactions of amines with a dimer of hexafluoropropene and with a perfluorovinyl sulfide prepared with hexafluoropropene

Some reactions of amines with a perfluorovinylsulfide, (CF₃)₂CFSC(CF₃)CFCF(CF₃)₂, prepared from hexafluoropropene (HFP) and sulfur [1] are compared to reactions of the same amines with the thermodynamic dimer of HFP, (CF₃)₂CCFCF₂CF₃. Many new ketenimines, eneamines, amidines, nitriles, and quinoline derivatives are reported.     

Fluorinated phosphorus compounds: Part 10. Bis(fluoroalkyl) S-alkyl phosphorothiolates and tris(fluoroalkyl) phosphorothionates

Treatment of bis(fluoroalkyl) phosphites (R_FCH₂O)₂P(O)H, where R_F was CF₃ or C₂F₅ with sulfur in pyridine at 80 °C gave salts of structure [(R_FCH₂O)₂P(O)SH]NC₅H₅ in 90 and 88% yield, respectively. The salts reacted with alkyl iodides in acetonitrile at 50 °C to furnish bis(fluoroalkyl) S-alkyl phosphorothiolates (R_FCH₂O)₂P(O)SR, where R was Me, Et, n- and i-Pr (when R_F = CF₃) and Me (when R_F = C₂F₅). Yields ranged from 21 to 57%. Bis(trifluoroethyl) S-methyl phosphorothiolate (CF₃CH₂O)₂P(O)SMe underwent fluorination by silver(I) fluoride in acetonitrile at room temperature to yield the phosphorofluoridate (CF₃CH₂O)₂P(O)F in 75% yield. Tris(fluoroalkyl) phosphorothionates (R_FCH₂O)₃P = S, where R_F was CF₃, C₂F₅ and C₃F₇, were prepared in 30-34% yield by heating the tris(fluoroalkyl) phosphites (R_FCH₂O)₃P and sulfur to 200 °C in a sealed tube for 8 h.     

Unusual reactions of N-(trifluoromethylsulfonylimino)di-and-trifluoromethanesulfinimidoyl chlorides

N-(Trifluoromethylsulfonylimino)di-and-trifluoromethanesulfinimidoyl chlorides RS(=NSO₂CF₃)Cl (R = CF₃, CHF₂) react with potassium fluoride in 1,2-dimethoxyethane with formation of the corresponding N,N′-bis(trifluoromethylsulfonyl)fluoromethanesulfinimidamide potassium salts RS(=NSO₂CF₃)NSO₂CF₃ ^?K. Analogous methanesulfinimidoyl and fluoromethanesulfinimidoyl chlorides (R = CH₃, CH₂F) fail to react with KF under similar conditions. Treatment of trifluoromethanesulfenamides CF₃SNR₂ with N,N-dichlorotrifluoromethanesulfonamide CF₃SO₂NCl₂ leads to N,N-disubstituted N′-(trifluoromethylsulfonyl)trifluoromethanesul-finimidamides CF₃S(=NSO₂CF₃)NR₂. The reaction of N,N-dimethyl-N′-(trifluoromethylsulfonyl)trifluoromethanesulfinimidamide (R = CH₃) with gaseous hydrogen chloride in diethyl ether gives sulfinimidoyl chloride CF₃S(=NSO₂CF₃)Cl which could not be obtained by imination of CF₃SCl.     

Mono and Bisphosphonates from Perfluoro Olefins and Polyfunctional Fluoro Ketones. Syntheses,Molecular Structure and Derivatives

Perfluoroalkenyl phosphonates were formed along with Me₃SiF using CF₃CF=CF₂, CF₃CH=CF₂, F₅SCF=CF₂ or F₅SCH=CF₂ and silylated phosphites, (R¹O)₂POSiMe₃ (R¹=Et, SiMe₃). This straightforward method could be extended to perfluorobutadienes CF₂=C(R^F)C(R^F)=CF₂ (R^F F=F, CF₃). The formation of CF₃C(=O)P(=O)(OSiMe₃)₂ and further reactions to yield bisphosphonates will be described. Acetylphosphonates, R²C(=O)P(=O)(OSiMe₃)₂ (R²=CH₃, CF₃) reacted with the ketimine, CH₃C(=NiPr)Ph to give α-hydroxy-γ-imino phosphonates. Trifluoroacetylphenol and 2,6-bis(trifluoracetyl)-4-methyl-phenol have been proven to be versatile precursors for α-and γ-hydroxy phosphonates. Intermediates in these reactions were found to be cyclic λ⁵σ⁵P species.     

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.     

Perfluoro- ω -iodo-3-oxaalkanesulfonyl fluorides as intermediates for surfactants and vinyl compounds

The well known fluorosulfonyldifluoroacetyl fluoride (I), FOCCF₂SO₂F (I) quantitatively formed from sulfur trioxide and TFE through the tetrafluoroethanesultone has been converted into the octafluoro- -5-iodo-3-oxapentanesulfonyl fluoride (II) ICF₂CF₂OCF₂CF₂SO₂F (II) by the well known reaction (1) involving MF, iodine, TFE in aprotic solvents.The iodo compound (II) allowed us to obtain TFE telomers having both fluorosulfonyl and iodo as terminal groups.The said telomers have been easily converted into surfactants (III) through fluorination and vinyl derivatives (IV) by dehalogenation.CF₃CF₂(CF₂CF₂)_nOCF₂CF₂SO₃M (III)CF₂CF(CF₂CF₂)_nOCF₂CF₂SO₂F (IV)     

Fluorinated phosphorus compounds: Part 6. The synthesis of bis(fluoroalkyl) phosphites and bis(fluoroalkyl) phosphorohalidates

Reaction of phosphorus trichloride with tert-butanol and fluoroalcohols gave bis(fluoroalkyl) phosphites (R_FO)₂P(O)H in 42-89% yield, where R_F=HCF₂CH₂, H(CF₂)₂CH₂, H(CF₂)₄CH₂, CF₃CH₂, C₂F₅CH₂, C₃F₇CH₂, (CF₃)₂CH, (FCH₂)₂CH, CF₃(CH₃)₂C, (CF₃)₂CH₃C, CF₃CH₂CH₂, C₄F₉CH₂CH₂ and C₆F₁₃CH₂CH₂. Treatment of these with chlorine in dichloromethane gave the bis(fluoroalkyl) phosphorochloridates (R_FO)₂P(O)Cl in 49-96% yield. The chloridate (CF₃CH₂O)₂P(O)Cl was isolated in much lower yield from the interaction of thionyl chloride with bis(trifluoroethyl) phosphite. Heating the latter in dichloromethane with potassium fluoride and a catalytic amount of trifluoroacetic acid gave the corresponding fluoridate (CF₃CH₂O)₂P(O)F in 84% yield. Treatment of bis(trifluoroethyl) phosphite with bromine or iodine gave the bromidate (CF₃CH₂O)₂P(O)Br and iodidate (CF₃CH₂O)₂P(O)I in 51 and 46% yield, respectively. The iodidate is the first dialkyl phosphoroiodidate to have been isolated and characterised properly—its discovery lags behind the first isolation of a dialkyl phosphorochloridate by over 130 years. The fluoroalkyl phosphoryl compounds are generally more stable than known unfluorinated counterparts.     

Electron-impact studies of organometallic molecules—VII. Some transition metal complexes derived from 3,3,3-trifluoroprop-1-yne

The mass spectra of ten complexes derived from 3,3,3-trifluoroprop-1-yne, namely (CF₃C?CH)CO₂(CO)₆, (CF₃C?CH) [π? C₅H₅Ni]₂, (CF₃C?CH)₃Co₂(CO)₄, CF₃CH₂C[Co(CO)₃]₃, are discussed in terms of their structures. The major processes observed can be satisfactorily explained in terms of (i) loss of carbonyl groups, if present; (ii) loss of one fluorine atom from the parention (iii) elimination of neutral metal fluorides, with ligand transfer reactions in the case of the iron complexes; (iv) elimination of neutral fluorocarbon molecules.     

A re-examination of the infrared and ultraviolet spectroscopy of trifluoroacetyl fluoride and trifluoroacetyl chloride: An experimental and theoretical study

The fundamental IR vibrational modes of trifluoroacetyl fluoride CF₃C(O)F and trifluoroacetyl chloride CF₃C(O)Cl have been re-examined by ab initio molecular orbital calculations and compared with literature assignments. Several bands of the IR spectrum are reassigned. The Q-branch and integrated absorption cross-sections have been measured for ν₁, ν₃, ν₄ and ν₁₁ fundamental bands for both pressurized and unpressurized samples on each molecule. The UV absorption spectra of CF₃C(O)F and CF₃C(O)Cl show a structureless continuum with a maximum at 21Onm (σ_max=3.20±0.02 × 10⁻²⁰ cm² molecule⁻¹) and 255 nm (σ_max=7.66±0.26 × 10⁻²⁰ cm² molecule⁻¹), respectively. The nature of the electronic transition giving rise to the UV absorption spectrum for CF₃C(O)F and CF₃C(O)Cl has been examined by ab initio molecular orbital calculations. It is attributed to the A¹A″←X¹A′ electronic transition.     

Theoretical studies of decomposition kinetics of CF3CCl2O radical

The unimolecular decomposition reaction of CF₃CCl₂O radical has been investigated using theoretical methods. Two most important channels of decomposition occurring via C–C bond scission and Cl elimination have been considered during the present investigation. Ab initio quantum mechanical calculations are performed to get optimized structure and vibrational frequencies at DFT and MP2 levels of theory. Energetics are further refined by the application of a modified Gaussian-2 method, G2M(CC,MP2). The thermal rate constants for the decomposition reactions involved are evaluated using Canonical Transition State Theory (CTST) utilizing the ab initio data. Rate constants for C–C bond scission and Cl elimination are found to be 6.7 × 10⁶ and 1.1 × 10⁸ s^?1, respectively, at 298 K and 1 atm pressure with an energy barrier of 8.6 and 6.5 kcal/mol, respectively. These values suggest that Cl elimination is the dominant process during the decomposition of the CF₃CCl₂O radical. Transition states are searched on the potential energy surface of the decomposition reactions involved and are characterized by the existence of only one imaginary frequency (NIMAG = 1) during frequency calculation. The existence of transition states on the corresponding potential energy surface is further ascertained by performing intrinsic reaction coordinate (IRC) calculation.     

A study of the structure and properties of mixed-ligand Cu(II) complexes with hexafluoroacetylacetone and methyl-, phenyl-ketoimines

The synthesis and X-ray single crystal study of two mixed-ligand Cu(II) complexes are performed: (CH₃C(NCH₃)CHC(O)CH₃)(CF₃C(O)CHC(O)CF₃)Cu (1) (space group P2₁/c, a = 7.0848(12) Å, b = 17.854(3) Å, c = 11.837(2) Å, β = 100.495(6)°, V = 1472.4(4) ų, Z = 4), (CH₃C(NC₆H₅)CHC(O)CH₃)· (CF₃C(O)CHC(O)CF₃)Cu (2) (space group P-1, a = 9.1119(4) Å, b = 9.6954(4) Å, c = 11.1447(6) Å, α = 113.784(2)°, β = 92.383(2)°, γ = 95.402(2)°, V = 893.52(7) ų, Z = 2). The structures are molecular, formed from neutral mixed-ligand copper complexes. The central copper atom has the (3O+N) coordination environment with average Cu-O distances of 1.948 Å and Cu-N of 1.932 Å; the chelate O-Cu-N angle (average) is 94.0°. In the structures, the complexes are linked into dimeric associates with Cu…Cu distances of 3.197 Å (for 1) and 3.246 Å (for 2). The volatility of mixed-ligand complexes 1 and 2 is in between of that of the starting homo-ligand complexes.     

The addition of small molecules to (η-C5H5)2Rh2(CO)(CF3C2CF3): IV. The sunlight assisted making and breaking of alkene CH bonds on the dirhodium centre; the crystal and molecular structures of (η-C5H5)2Rh2(CHCHCN){C(CF3)CF3)H} · H2O and (η-C5H5)2Rh2(CHCF2){C(CF3)C(CF3)H}

Bis-alkenyl complexes of the type (η-C₅H₅)₂RH₂(alkene − H)(alkyne + H) are obtained when the alkyne complex (η-C₅H₅)₂Rh₂(CO)(CF₃C₂CF₃) is treated with the following alkenes: H₂CCH₂, H₂CCHR (R = Me, Bu^t, Ph, CN), H₂CCF₂, RHCCHR′ (R = R′ = Me, Ph, Cl; R = Me, R′ = Et), cyclooctene and norbornene. An approximately equimolar amount of (η-C₅H₅)₂Rh₂(CO)₂(CF₃C₂CF₃) is also formed. The reactions are greatly accelerated when the reaction mixtures are exposed to sunlight. There is some regioselectivity in the reactions with H₂CCHR and MeHCCHet, with a preference for CH bond cleavage at the least crowded alkene-carbon. When the reaction with acrylonitrile is performed in the absence of sunlight, the complex (η-C₅H₅)₂(CO){(H₂CCHCN)(CF₃C₂CF₃)} can be isolated; upon exposure to sunlight, there is loss of CO and H-transfer to form two isomers of the appropriate bis-alkenyl complex.The molecular geometries of (η-C₅H₅)₂Rh₂(CHCHCN){C(CF₃)C(CF₃)H} and (η-C₅H₅)₂Rh₂(CHCF₂){C(CF₃)C(CF₃)H} have been ascertained by X-ray structure determination. Each molecule has two bridging alkenyl units spanning a RhRh single bond; the dihedral angle between the two RhRhCC planes is just above 90°. There is a cyclopentadienyl ring η⁵-attached to each metal. Crystal data: C₁₇H₁₃F₆NRh₂·H₂O, M 569.1, monoclinic, P2₁/n, a 15.014(7), b 14.882(7), c 8.590(5) Å, β 94.57(9)°, Z = 4, final R 0.056 for 2493 observed reflections; C₁₆H₁₂F₈Rh₂, M 562.1, monoclinic, P2₁/c, a 13.037(6), b 8.765(2), c 14.873(3) Å, β 103.16(3)°, Z = 4, final R 0.062 for 1820 observed reflections.     

Lewis acid catalyzed heavy atom tunneling – the case of 1H-bicyclo[3.1.0]-hexa-3,5-dien-2-one

For many thermal reactions, the effects of catalysis or the influence of solvents on reaction rates can be rationalized by simple transition state models. This is not the case for reactions controlled by quantum tunneling, which do not proceed via transition states, and therefore lack the simple concept of transition state stabilization. 1H-Bicyclo[3.1.0]-hexa-3,5-dien-2-one is a highly strained cyclopropene that rearranges to 4-oxocyclohexa-2,5-dienylidene via heavy-atom tunneling. H₂O, CF₃I, or BF₃ form Lewis acid–base complexes with both reactant and product, and the influence of these intermolecular complexes on the tunneling rates for this rearrangement was studied. The tunneling rate increases by a factor of 11 for the H₂O complex, by 23 for the CF₃I complex, and is too fast to be measured for the BF₃ complex. These observations agree with quantum chemical calculations predicting a decrease in both barrier height and barrier width upon complexation with Lewis acids, resulting in the observed Lewis acid catalysis of the tunneling rearrangement.

The ring-opening of a highly strained cyclopropene to a carbene proceeds via heavy-atom tunneling. This rearrangement is accelerated in the presence of H₂O, ICF₃ or BF₃, resulting in a novel Lewis-acid catalyzed tunneling reaction.     

Chlorine initiated photooxidation studies of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs): Results for HCFC-22 (CHClF2); HFC-41 (CH3F); HCFC-124 (CClFHCF3); HFC-125 (CF3CHF2); HFC-134a (CF3CH2F); HCFC-142b (CClF2CH3); and HFC-152a (CHF2CH3)

Data on the tropospheric degradation of proposed substitutes for ozone depleting CFCs were obtained by conducting photochemical oxidation studies of HCFCs and HFCs using long path Fourier transform infrared spectroscopy. The hydrogen abstraction reactions were initiated using Cl radicals rather than OH radicals because of the rather unreactive nature of the compounds. The experimental product yields at T = 25 ± 3°C and 700 Torr of dry air were: CHClF₂ (1.11 ± 0.06 C(O)F₂); CClFHCF₃ (1.00 ± 0.04 CF₃C(O)F); CF₃CHF₂ (1.09 ± 0.05 C(O)F₂); CClF₂CH₃ (0.98 ± 0.03 C(O)F₂); CHF₂CH₃ (1.00 ± 0.05 C(O)F₂); CF₃CH₂F (0.16 ± 0.03 CF₃CF(O), and 0.83 ± 0.22 HFC(O)), where all standard deviations are 2σ. For each compound, the critical step in determining the oxidation products was the decomposition of a halogenated alkoxy radical. For HCFC-22 and HCFC-124, the major alkoxy radical decomposition route was Cl elimination. The HFC-125 product data were consistent with C? C cleavage of a two carbon alkoxy radical as the major decomposition route whereas both C? C cleavage and H abstraction by O₂ were significant contributors to the decomposition of the HFC-134a alkoxy radical. Secondary Cl reactions in the HCFC-142b and HFC-152a experiments prevented an unambiguous determination of the decomposition modes; the data are consistent with both C? C bond scission and Cl reactions with halogenated aldehydes producing the oxidation product C(O)F₂. With the exception of the HFC-134a and HFC-125 data, the proposed mechanisms can account for the major oxidation products. For HFC-134a and HFC-125, a number of product bands could not be identified. The bands are likely due to products from reactions involving the CF₃O₂ radical. © John Wiley & Sons, Inc.     

Some diels—alder reactions of η1-bonded cyclopentadienylmetal compounds

Bis(cyclopentadienyl)mercury readily undergoes Diels—Alder reactions with RCCR (R = CO₂Me or CF₃), CF₃CFCFCF₃, CF₃CFCF₂, (CF₃)₂CC(CN)₂, C₂(CN)₄ and Ph$\text{NCONNC}$O to give stable adducts characterised by¹H, ¹⁹F and ¹³C NMR, spectroscopy. Similar reactions of CF₃CCCF₃ and CF₃CFCFCF₃ with the cyclopentadiene derivatives Me₃MC₅H₅ and (Me₃M)₂C₅H₄ (M = Si, Sn) are also described.     

Fluorinated phosphorus compounds: Part 8. The reactions of bis(fluoroalkyl) phosphorochloridates with sulfur nucleophiles

The reactivity of bis(fluoroalkyl) phosphorochloridates to nucleophiles is summarised. Previous data and the results described here indicate that reactivities decrease in the order: amines>alcohols>thiols. The synthesis of CF₃CH₂OP(O)(SEt)₂ in 30% yield was accomplished by treating CF₃CH₂OP(O)Cl₂ with two molar equivalents of EtSH and Et₃N in ether. The chloridates (CF₃CH₂O)₂P(O)Cl and (C₂F₅CH₂O)₂P(O)Cl did not react with MeSH in ether at −78 °C or when heated with Pb(SMe)₂ in benzene. Ethanethiol and propanethiol reacted with fluorinated chloridates in the presence of triethylamine to give thiolates (R_FO)₂P(O)SR in 13-41% yield where R_F was CF₃CH₂, C₂F₅CH₂, C₃F₇CH₂ or (CF₃)₂CH and R was Et or n-Pr. Similarly, reaction of phosphorobromidates (R_FCH₂O)₂P(O)Br, made by brominating the corresponding bis(fluoroalkyl) H-phosphonates, with benzenethiol gave derivatives (R_FCH₂O)₂P(O)SPh in 43 and 46% yield where R_F was CF₃ and C₂F₅, respectively. Treatment of the chloridothiolate Cl(EtO)P(O)SMe, prepared in two steps from triethyl phosphite, with fluoroalcohols and triethylamine in ether gave species R_FO(EtO)P(O)SMe in 62-74% yield where R_F was CF₃CH₂, C₂F₅CH₂, C₃F₇CH₂ or (CF₃)₂CH. The reactions of bis(trifluoroethyl) phosphorochloridate with 2-mercaptoethanol, 3-mercaptopropanol and ethane-1,2-dithiol gave several unexpected products whose structures were tentatively assigned.     

A theoretical investigation on the kinetics and reactivity of the gas-phase reactions of ethyl chlorodifluoroacetate with OH radical and Cl atom at 298 K

The mechanism, kinetics, and thermochemistry of the gas-phase reactions of CF₂ClC(O)OCH₂CH₃,ethyl chlorodifluoroacetate (ECDFA) with the OH radical and Cl atom are investigated. Geometry optimization and frequency calculations have been performed at the MPWB1K/6-31+G(d,p) level of theory and energetic information is refined by using G2(MP2) theory. Transition states are searched on the potential energy surface of reaction channels and each of the transition states is characterized by the presence of only one imaginary frequency. Connections of the transition states between designated local minima are confirmed by intrinsic reaction coordinate calculation. Theoretically calculated rate constants at 298 K using the Canonical Transition State Theory are found to be in good agreement with the experimentally measured ones. Using group-balanced isodesmic reactions as working chemical reactions, the standard enthalpies of formation for CF₂ClC(O)OCH₂CH₃, CF₂ClC(O)OCH₂CH₂, and CF₃C(O)OCHCH₃ are also reported for the first time. The hydrogen abstraction occurs mainly from –CH₂ group. The T1 diagnostic calculation suggests that the multi-reference character is not an issue for such systems. The estimated atmospheric life time of ECDFA is expected to be around 24 days.