The CW-CO2 laser induced reaction of 1,1-difluoroethane with chlorine

The CW–CO₂ laser induced reaction of CF₂HCH₃ (1) with Cl₂ yields vinylidene fluoride (2) as the main product; other products are CH₃CF₂Cl (3), CF₂ClCH₂Cl (4), CF₂ = CHCl (5), CF₂ = CCl₂ (6) and CF₂ Cl₂ (7). The yield dependence of 2 on the CF₂HCH₃/Cl₂ ratio, the laser irradiation time, the laser power and the pressure of the gaseous reactants have been investigated. Furthermore, the TEA–CO₂ laser induced reaction of 1 with Cl₂. the CW–CO₂ laser induced reaction of 2 and 2 with Cl₂ have also been studied in order to gain more mechanistic insights for this complicated reaction system. Apparently, CF₂ClCH₃ but not CF₂HCH₂Cl. is the main precursor to 2. Interestingly, it has been found that the relatively strong double bond of CF₂ = CH₂ can be broken by laser irradiation. The possibility of applying this laser methodology to the production of vinylidene fluoride has been discussed.     

Low energy electron impact on chlorofluoromethanes and CF4: Resonances,dissociative attachment and excitation

Electron transmission spectra, dissociative attachment studies and threshold electron-impact excitation spectra are presented for CFCl₃, CF₂Cl₂, CF₃Cl and CF₄. Sharp vibrational progressions, which are ascribed to a new type of resonance, have been discovered in transmission spectra below 2 eV. A survey is given of the dissociative attachment processes in the compounds studied. Some of these processes have not been described previously. New assignments are suggested for the optical spectrum of CF₃Cl. Approximate triplet energies of the chlorofluoromethanes and the chlorornethanes are given.     

Preparation and properties of perfluorochloromethyl-mercaptophosphoryldichlorides and -chlorophosphanes

In Arbuzov-type reactions CF_nCl_3?nSCl reacts with ROPCl₂ (R = CH₃, C₂H₅) to give CF_nCl_3?nSP(O)Cl₂ (n = 3,2,1,0). The corresponding reaction with CF₃SeX (X = Cl, Br) produces CF₃SeP(O)Cl₂ in good yields only in the presence of catalysts such as SbCl₅ or BCl₃. Reactions between P₄ and the sulfenylchlorides produce (CF_nCl_3?nS)_xPCl_3?n (n = 3,2,1 and x = 1,2). On heating CF_n′ Cl_3?n′ SP(O)Cl₂ (n′ = 2,1,0) decompose to P(O)Cl₃ and SCF_n′ Cl_2?n′. During this process fluorination of P(O)Cl₃ to P(O)F₃ by SCF₂ is observed. A Cl/Br exchange between CF_nCl_3?nSP(O)Cl₂ (n = 3,2) and PBr₃ was proved ¹⁹F? and ³¹P-NMR-spectroscopically.Chemical and physical properties of the newly synthesized compounds will be discussed.     

Reaktionen von Sulfensäurefluoriden: Synthese,Charakterisierung und NMR-Studien von Perhalogenalkylmercaptotetrafluorphosphoranen

Reactions of Sulfenic Fluorides: Synthesis, Characterization and N.M.R. Studies of Perhalogenalkylmercaptotetrafluorphosphoranes Marcaptotetrafluorophosphoranes R_fSPF₄ (R_f = CF₃, CF₂Cl) are obtained by the reaction of sulfenic fluorides R_fSF with PF₃. The compounds formed are extremely sensitive to hydrolysis. They react with H₂O yielding R_fSH, HF and POF₃ as well as with an excess of R_fSF to give PF₅ and R_fSSR_f. NMR studies were performed at various temperatures.     

Negative ion formation in CF2Cl2, CF3Cl and CFCl3 following low energy (0—10 eV) impact with near monoenergetic electrons

Negative ion formation in CF₂Cl₂, CF₃Cl and CFCl₃ under low-energy electron impact has been investigated using a trochoidal monochromat The ions observed are F^?, Cl^?, FCl^?, Cl₂^?, CFCl₂^? from CF₂Cl₂; F^?, Cl^?, FCl^?, CF₂Cl Quoting available thermochemical data, it can be shown that most of the observed negative ions arise from dissociative attachment processes. Appearance The extremely high yield of Cl^? in CFCl₃, which is observed at ε = 0.0 eV, will be discussed with regard to the lifetime of this molecule i     

The CO_2 laser-induced radical-chain reactions between CH_3CF_2H and chlorine-atom donors CF_2ClCFCl_2, CF_3CCl_3 CFCl_3 or CF_2Cl_2

The CO_2 laser induced room temperature reactions of CH_3CF_2H or another protium-donorCH_3CHClCH_3 with chlorine-atom donors (Z--Cl) CFCl_2CF_2Cl, CF_3CCl_3, CFCl_3 or CF_2Cl_2, havebeen investigated. Some of these reactions can yield two important monomers (CF_2=CH_2 andCF_2=CFCl) for fluoropolymers simultaneously. The yield dependence of these two alkenes on experi-mental conditions has been studied. A laser-initiated chain process is supported by identifica-tion of Z--H intermediates in these reactions.     

Photodissociation of CF3NO: observation of NO (υ=1)

That excitation of CF₃NO with wavelengths between 580 and 660 nm yields CF₃ + NO has been shown by two direct techniques. In the first, the CF₃ and NO radicals have been scavenged by their reaction with Cl₂ to yield CF₃Cl and NOCl. as detected by both infrared and mass spectrometry. In the second technique, NO (υ=1) vibrational fluorescence has been observed following tunable dye laser excitation of CF₃NO. The rate of vibrational relaxation of NO (υ=1) in collisions with CF₃NO has been found to be (2.19 ± 0.19) × 10³ s^?1 torr ^?1.     

Chlorofluorieren mit Trifluormethylhypochlorit CF3OCl. Darstellung und spektroskopische Charakterisierung von Trifluormethyliodchloridfluorid CF3I(Cl)F

Chlorofluorinate with Trifluoromethylhypochlorite CF₃OCl. Preparation and Spectroscopic Characterization of Trifluormethyliodinechloridefluoride CF₃I(Cl)F The preparation of a new iodine(III) compound, trifluormethyliodinechloridefluoride CF₃I(Cl)F, via oxidative addition of trifluoromethylhypochlorite CF₃OCl to trifluoromethyliodide CF₃I is described. The thermolabile compound has been characterized by i.r., Raman, ¹⁹F NMR, and mass spectroscopy.     

New pentafluoro-λ-sulfanyl (SF5) perfluoroalkyl benzene derivatives

Preparation of the following new SF₅-perfluoroalkyl benzene derivatives, m-SF₅CF₂CF₂C₆H₄X (X=NO₂, NH₂, OH, I, NHCOCH₃, SO₂Cl, SO₃H, SO₃K) has been achieved. The new compounds were characterized by their respective IR, NMR and HRMS or elemental analysis.     

The synthesis and structural characterisation of an homologous series of group 14 1-chloro-2,2-difluorovinyl compounds

A series of group 14 1-chloro-2,2-difluorovinyl compounds Ph₃E(CClCF₂) (E=Ge, Sn, Pb) has been prepared using the low temperature reactions of 1-chloro-2,2-difluorovinyllithium (LiCClCF₂), generated in situ from CF₃CH₂Cl (HCFC-133a) and n-butyllithium. These new materials have been fully characterised, including for E=Ge and Sn, by single crystal X-ray studies. This is the first time that any main-group 1-chloro-2,2-difluorovinyl compounds have been crystallographically studied.     

Reactivity of olefin an acetylene complexes of platinum(0) towards tetrachloro-o-benzoquinone

Tetracloro-o-benzoquinone reacts with (diphenylacetylene)bis(tirphenylphosphine)platinum(0) to give the novel platinum(II) diphenylacetylene complex, Pt(C₆Cl₄O₂)PhCCPh)(PPh₃), (I), which reacts with hydrogen halides to give the compelexes cis-PtX₂(PhCCPh((PPh₃), (X = Cl or Br). Hydrogen chloride also readily removes the tetrachloro-o-benzoquinoneligand from the adducts Ni(C₆Cl₄O₂)(Ph₂PCH₂CH₂PPh₂) and M(C₆Cl₄O₂)(PPh₃)₂, (M = Pd or Pt) but it has no reaction upon Ir(Cl)(C₆Cl₄O₂)(CO)(PPh₃)₂ at room temperature. The acetylene in (1) is susceptible to nucleophilic attact and reaction with diethylamine gives the vinyl adduct Pt(C₆Cl₄O₂)(CPhCPh)NHEt₂)(PPh₃). Other reactions of (I) have also been studied. Attemps to prepare other olefin or acetylene complexes of platinum(II) by the action of tetrachlor-o-benzoquinone on the complexes Pt(L)(PPh₃)₂, (L = PhCCH,(Et)(Me)(HO)CCCC(OH)(Me)(Et), HOCH₂OH, CF₃CCCF₃, CF₂CF₂, CF₂CH₂ or trans-PhCHCHPh) are also described.     

Similarities in the Intensities of Analogous Rydberg–Rydberg Transitions in the Molecular Series CF x Cl y (x=3, 2, 1; y=1, 2, 3)

In this work, the photoabsorption behaviour of the molecular series CF₃Cl, CF₂Cl₂ and CFCl₃, involving their ground state and two different Rydberg series, has been studied. The discrepancies or similarities in the intensities of homologous transitions in the three CF _x Cl _y molecules have been analysed on account of their electronic structure. Absorption oscillator strengths have been calculated with the Molecular quantum defect orbital (MQDO) approach. Electronic transitions between states belonging to two different unperturbed Rydberg series of the same molecule have been calculated by us for the first time. The quality of the achieved oscillator strengths has been assessed by comparison with, to our knowledge, scarce experimental data available in the literature, through analysis of the discrepancies or similarities in the intensities of homologous transitions in the molecular series CF _x Cl _y when states of different type are involved, and by testing the compliance of regularities by the Rydberg series object of our study.Article for the special issue dedicated to J.-P. Malrieu     

Preparation and structural investigations of fluorinated tungsten(vi) alkoxides

The preparation and characterization of compounds of composition Cl_6-xW(OCH₂CF₃)_x (x = 1−6) and X₄W[OC(CH₃) (CF₃)₂]₂ (X = Cl,F) together with ¹⁹F NMR spectra are reported. An X-ray structure analysis of Cl₄W[OC(CH₃)(CF₃)₂]₂ shows a W-O-C angle of 173.6°, which is unusually large for metal alkoxides, and a short W-O distance of 181.9 pm. A discussion on structural aspects and a comparison with related tungsten-nitrogen compounds are presented. Cl₄W[OC(CH₃) (CF₃)₂]₂ is monoclinic, space group C2/m, with a = 820.3(2), b = 1059.2(2), c = 1071.6(2) pm, β = 99.72(2)°, Z = 2 and was refined to R = 0.031 for 848 observed reflections.     

Darstellung und Eigenschaften von Trifluormethylmercaptothiophosphoryldichlorid

Preparation and Properties of Trifluoromethylmercaptothiophosphoryldichloride The reaction of CF₃SP(O)Cl₂ with SPCl₃ leads to a CF₃S-chlorine exchange and gives CF₃SP(S)Cl₂ in 50% yield. A controlled hydrolysis of CF₃SP(O)Cl₂ affords CF₃SP(O)(OH)₂, that cannot be isolated as such, but it condenses to CF₃SP(O)(OH)O? [P(SCF₃)(O)? O]_nP(O)(OH)SCF₃. On the other hand, CF₃SP(S)Cl₂ reacts with water to yield H₃PO₄, CF₃SH, S₈, and HCl. CF₃SP(X)Cl₂ reacts with alcohols to give CF₃SP(X)(OR)₂ [R = CH₃, C₂H₅, n-C₃H₇, CH(CH₃)₂, n-C₄H₉ and for X = O, R = C₆H₅, too]. The formation of semi-esters CF₃SP(X)Cl(OR′) could be proven for X = O, R′ = CH₃, C₆H₅ and for X = S, R′ = R. While CF₃SP(O)(OC₂H₅)₂ rapidly decomposes into SCF₂ and FP(O)(OC₂H₅)₂, the other compounds and primarily CF₃SP(O)(OCH₃)₂ and CF₃SP(S)(OR)₂ ar stable. The reaction between CF₃SCl and CH₃SPCl₂ results in CF₃SCH₂SPCl₂ and that between CF₃SP(O)Cl₂ and AlCl₃ gives [CF₃SP(O)Cl]⁺[AlCl₄]^?. Physical and spectroscopical data are given for the newly formed compounds.     

Trifluoromethanesulfonato complexes of (1,4,8,11-tetraazacyclotetradecane)cobalt(III) and ruthenium(III) with trans geometry

Reaction of trans-[M(cyclam)Cl₂]Cl (M = Co, Ru; cyclam = 1,4,8,11-tetra-azacyclotetradecane) with anhydrous CF₃SO₃H at elevated temperatures formed initially trans-[M(cyclam)Cl(OSO₂CF₃)](CF₃SO₃), with trans-[M(cyclam)(OSO₂CF₃)₂](CF₃SO₃) formed after extended reaction time. The complexes were characterized by spectroscopy, and rate constants for the rapid aquation of the bound CF₃SO₃⁻ determined. In the case of the cobalt(III) complexes, derivatives were prepared by substitution of the CF₃SO₃⁻ ligand by the neutral ligands acetonitrile and dimethylformamide.     

Some highly fluorinated acyclic,cyclic, and polycyclic derivatives of Cl2NCF2CF2NCl2 and Cl2CNCCl2CCl2NCCl2

When Cl₂NCF₂CF₂NCl₂ is heated with CF₂CFX (X = Cl, F) ClXCFCF₂N(Cl)CF₂CF₂N(Cl)CF₂CXClF (X = Cl, 2 ; F, 3 ) is formed. Mercury extracts chlorine fluoride from 2 and 3 to form new polyfluorobisazomethines, ClXCFCF₂NCFCFNCF₂CXClF (X = Cl, 4 ; F, 5 ). Photolysis of the product obtained from CCl₂NCCl₂CCl₂NCCl₂ with ClF, CF₂ClN(Cl)CF ClCFClN(Cl)CF₂Cl ( 6 ) gives another bisazomethine, CF₂ClNCFCFNCF₂Cl ( 7 ) with concomitant loss of Cl₂. At 25°C, in the presence of CsF, 4 and 5 are cyclized to give (X = Cl, 8 ; F, 9 ), and 7 forms a bicyclic derivative at 100°C, ( 1 ). Addition of chlorine fluoride to 8 and to 1 produces ( 10 ) and ( 14 ), respectively. Photolysis of 10 results in the loss of CFCl₃ to form ( 11 ), and 14 loses Cl₂ and dimerizes to the hydrazine ( 15 ). The further addition of ClF to 11 gives rise to ( 12 ) which when photolyzed at 3000 Å forms a second cyclic hydrazine, ( 13 ).     

Kinetics of the reactions of halogenated methyl radicals (CF3, CF2Cl,CFCl2, and CCl3) with molecular chlorine

The kinetics of four gas-phase reactions involving halogenated methyl radicals (R ? CF₃, CF₂Cl, CFCI₂, and CCI₃) with molecular chlorine have been studied using a tubular reactor coupled to a photoionization mass spectrometer. The radicals were homogeneously generated by the pulsed photolysis of precursor molecules at 193 nm. The subsequent decays of the radical concentration were monitored in real-time experiments as a function of Cl₂ concentration to obtain the rate constants of these R + Cl₂ reactions. Where possible, the rate constants were measured as a function of temperature to determine Arrhenius parameters. Apparent discrepancies between these measured rate constants for CF₃ and CCl₃ with Cl₂ and ones obtained in prior indirect studies are explained. The higher activation energies for these R + Cl₂ reactions compared to that of the CH₃ + Cl₂ reaction are attributed in part to the different polarities of the transition states formed.     

Highly trifluoromethylated platinum compounds

The homoleptic, square‐planar organoplatinum(II) compound [NBu₄]₂[Pt(CF₃)₄] ( 1 ) undergoes oxidative addition of CF₃I under mild conditions to give rise to the octahedral organoplatinum(IV) complex [NBu₄]₂[Pt(CF₃)₅I] ( 2 ). This highly trifluoromethylated species reacts with Ag⁺ salts of weakly coordinating anions in Me₂CO under a wet‐air stream to afford the aquo derivative [NBu₄][Pt(CF₃)₅(OH₂)] ( 4 ) in around 75 % yield. When the reaction of 2 with the same Ag⁺ salts is carried out in MeCN, the solvento compound [NBu₄][Pt(CF₃)₅(NCMe)] ( 5 ) is obtained in around 80 % yield. The aquo ligand in 4 as well as the MeCN ligand in 5 are labile and can be cleanly replaced by neutral and anionic ligands to furnish a series of pentakis(trifluoromethyl)platinate(IV) compounds with formulae [NBu₄][Pt(CF₃)₅(L)] (L=CO ( 6 ), pyridine (py; 7 ), tetrahydrothiophene (tht; 8 )) and [NBu₄]₂[Pt(CF₃)₅X] (X=Cl ( 9 ), Br ( 10 )). The unusual carbonyl–platinum(IV) derivative [NBu₄][Pt(CF₃)₅(CO)] ( 6 ) is thermally stable and has a ν_CO of 2194 cm^?1. The crystal structures of 2? CH₂Cl₂, 5 , [PPh₄][Pt(CF₃)₅(CO)] ( 6′ ), and 7 have been established by X‐ray diffraction methods. Compound 2 has shown itself to be a convenient entry to the chemistry of highly trifluoromethylated platinum compounds. To the best of our knowledge, compounds 2 and 4 – 10 are the organoelement compounds with the highest CF₃ content to have been isolated and adequately characterized to date.     

Molecular structure of trichlorophosphazo compounds from ab initio calculation and chlorine-35 NQR spectroscopy data

The molecular structures of trichlorophosphazo compounds Cl₃P=NR with R = C(CH₃)₃, C(C₂H₅)₃, C(CF₃)₃, CCl(CF₃)₂, CCl₂CF₃, CCl₃, CCl₂CCl₃, and CCl(CCl₃)₂ were analyzed by combined consideration of the results of ab initio MP2/6-31G* calculations and previously measured ³⁵Cl NQR frequencies. The conformational peculiarity of these molecules caused by the relative spatial orientations of the P-Cl and N-C bonds is reflected in the calculated geometric parameters of the Cl₃P=NC fragments and in the pattern of ³⁵Cl quadrupole resonance spectra for PCl₃ groups. For these atomic groups, the ³⁵Cl NQR frequencies were brought in correlation with the charges of the chlorine atoms found by quantum-chemical calculations.     

Radiation chemistry of CF2 Cl2 in the gas and liquid phases: Effect of doses rate

The dose rate dependence of CF₂ Cl₂ decomposition was studied in both, gas and liquid phase, for the range of 2.95·10^{1 7}–1.9·10^{1 9} eV·g^–1·h^–1. The major products were found to be CF₃Cl, CFCl₃, CF₂Cl–CF₂Cl and CF₂Cl–CFCl₂. The decomposition of CF₂Cl₂ was found to decrease with decreasing dose rate for the liquid phase, while an opposite trend was found for gas phase radiolysis. A new mechanism which explains these contrasting findings was suggested. The contribution of radical and of ionic (or molecular) processes to the yields of the various products was estimated.