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1.
The title compound has been synthesized by oxidation of pentafluorophenyl chloride with elemental fluorine.
Pentafluorophenylchlorine(III) difluoride was a colorless liquid (Boiling Point 96–98°C) which fumed when exposed to air. It oxidized 2.0 equivalents of iodide ion and did not decolorize a 0.1 M potassium permanganate solution. Anal. calcd. for C6F5ClF2: C, 29.96; F, 55.29; Cl, 14.74. Found: C, 29.79; F, 55.07; Cl, 14.90. The 19F nuclear magnetic resonance spectrum at 25°C consists of a doublet at 141.63, a triplet at 157.05, and a triplet at 162.25 ppm (CFCl3). The liquid phase infrared spectrum contains absorption bands as 703 (s), 640 (vs), 621 (vs), 553 (vs), 530 (s), 502 (w), 459 (s), 425 (s), 395 (m), 370 (m), 334 (m), 315 (vs), 301 (m), 278 (m), 242 (vw), and 220 (vw) cm?1.Molecular ions at m/e 240 and 242 accompanied by supporting fragmentation patterns, were present in the mass spectrum along with the isotopic ratio of approximately 3:1 as expected for the 35Cl and 37Cl. The mass spectrum of C6F5ClF2 consists of peaks assigned to C6F5ClF2+ (13), C6F5ClF+ (0.71), C6F5Cl+ (26), C6F4Cl+ (0.92), C6F6+ (6.7), C6F5+ (29), C6F4+ (0.72), C5F3+ (100), ClF2+ (1.1), ClF+ (0.7), and Cl+ (0.2). Metastable ions were observed in the following region: 184.5, 170.0, 165.6 and 56.0. The peak at m/e 240 showed a very weak metastable peak at m☆ = 144.0 from the process: 240→186 + ClF°.  相似文献   

2.
We have optimized the analytical parameters of a homemade instrument for the simultaneous measurement of the chlorofluorocarbons CCl2F2 (CFC-12), CCl3F (CFC-11) and C2Cl3F3 (CFC-113) in seawater. Seawater samples are flame sealed into 60 ml glass ampoules avoiding any contact with the atmosphere and stored in cold, dark condition until analysis. In the laboratory, after cracking the ampoule in an enclosed chamber filled with ultra-pure nitrogen, the seawater sample is transferred to a stripping chamber, where ultra-pure nitrogen is used to purge the dissolved CFCs from the seawater. The extracted gases are then cryogenically trapped, subsequently the trap is isolated and heated and the CFCs are transferred by a carrier gas stream into a precolumn and then are separated on a gaschromatographic packed column. To separate adequately CFC-12 from N2O, during the early part of the chromatographic run, the gas stream passes through a molecular sieve, which is then isolated and backflushed. The CFCs are detected on an electron capture detector (63Ni ECD). After a careful choice of the experimental conditions, the performances of the system were evaluated. The detection limits for seawater samples are: 0.0081 pmol kg−1 for CFC-12, 0.0073 pmol kg−1 for CFC-11 and 0.0043 pmol kg−1 for CFC-113. The reproducibility of replicate samples lies within 5% for the three CFCs. The system has been successfully employed for CFC measurements in seawater samples collected in the Ross Sea (Antarctica) in the framework of the Italian Antarctic research project.  相似文献   

3.
Recent results on the surface modification of petroleum cokes and their electrochemical properties as anodes of secondary lithium batteries are summarized. The surface of petroleum coke and those heat-treated at 1860-2800 °C were fluorinated by elemental fluorine (F2), chlorine trifluoride (ClF3) and nitrogen trifluoride (NF3). No surface fluorine was found except only one sample when ClF3 and NF3 were used as fluorinating agents while surface region of petroleum coke was fluorinated when F2 was used. Transmission electron microscopic (TEM) observation revealed that closed edge of graphitized petroleum coke was destroyed and opened by surface fluorination. Raman spectra showed that surface fluorination increased the surface disorder of petroleum cokes. Main effect of surface fluorination with F2 is the increase in the first coulombic efficiencies of petroleum cokes graphitized at 2300-2800 °C by 12.1-18.2% at 60 mA/g and by 13.3-25.8% at 150 mA/g in 1 mol/dm3 LiClO4-ethylene carbonate (EC)/diethyl carbonate (DEC) (1:1, v/v). On the other hand, main effect of the fluorination with ClF3 and NF3 is the increase in the first discharge capacities of graphitized petroleum cokes by ∼63 mAh/g (∼29.5%) at 150 mA/g in 1 mol/dm3 LiClO4-EC/DEC.  相似文献   

4.
The primary phosphines MesPH2 and tBuPH2 react with 9-iodo-m-carborane yielding B9-connected secondary carboranylphosphines 1,7-H2C2B10H9-9-PHR (R=2,4,6-Me3C6H2 (Mes; 1 a ), tBu ( 1 b )). Addition of tris(pentafluorophenyl)borane (BCF) to 1 a , b resulted in the zwitterionic compounds 1,7-H2C2B10H9-9-PHR(p-C6F4)BF(C6F5)2 ( 2 a , b ) through nucleophilic para substitution of a C6F5 ring followed by fluoride transfer to boron. Further reaction with Me2SiHCl prompted a H−F exchange yielding the zwitterionic compounds 1,7-H2C2B10H9-9-PHR(p-C6F4)BH(C6F5)2 ( 3 a , b ). The reaction of 2 a , b with one equivalent of R'MgBr (R’=Me, Ph) gave the extremely water-sensitive frustrated Lewis pairs 1,7-H2C2B10H9-9-PR(p-C6F4)B(C6F5)2 ( 4 a , b ). Hydrolysis of the B−C6F4 bond in 4 a , b gave the first tertiary B-carboranyl phosphines with three distinct substituents, 1,7-H2C2B10H9-9-PR(p-C6F4H) ( 5 a , b ). Deprotonation of the zwitterionic compounds 2 a , b and 3 a , b formed anionic phosphines [1,7-H2C2B10H9-9-PR(p-C6F4)BX(C6F5)2][DMSOH]+ (R=Mes, X=F ( 6 a ), R=tBu, X=F ( 6 b ); R=Mes, X=H ( 7 a ), R=tBu, X=H ( 7 b )). Reaction of 2 a , b with an excess of Grignard reagents resulted in the addition of R’ at the boron atom yielding the anions [1,7-H2C2B10H9-9-PR(p-C6F4)BR’(C6F5)2] (R=Mes, R’=Me ( 8 a ), R=tBu, R’=Me ( 8 b ); R=Mes, R’=Ph ( 9 a ), R=tBu, R’=Ph ( 9 b )) with [MgBr(Et2O)n]+ as counterion. The ability of the zwitterionic compounds 3 a , b to hydrogenate imines as well as the Brønsted acidity of 3 a were investigated.  相似文献   

5.
After publication of the above paper, the possibility of the presence of an isomeric iodide, 2,2-dichloroiodotrifluoroethane, in the title compound when prepared by the addition of ICI to chlorotrifluoroethylene, was pointed out by Dr. R. E. Banks of the University of Manchester Institute of Science and Technology, Manchester, U.K. The title compound was purchased from a commercial source and on enquiry we learned that it was indeed prepared by the addition of ICI to chlorotrifluoroethylene at sub-ambient temperature. Even though the compound had been subjected to routine Gas Chromatographic analysis before work was started and we could not detect more than one component, we subsequently examined it by 19F NMR. The results showed that it was contaminated by ∼ 19% of the isomeric iodide. We deeply regret this oversight and thank Dr. Banks for pointing out the possibility. The presence of this isomer can explain the formation of CFC12CF2CFC12 and CF2C1CFC1CF2CFC12 among the products we observed, though it alone cannot possibly account for the formation of chlorotrifluoroethylene, C6F9C15 and C8F12C16. Further work is in progress and will be communicated at a future date. will be communicated at a future date.  相似文献   

6.
Molybdenum(VI) bis(imido) complexes [Mo(NtBu)2(LR)2] (R=H 1 a ; R=CF3 1 b ) combined with B(C6F5)3 ( 1 a /B(C6F5)3, 1 b /B(C6F5)3) exhibit a frustrated Lewis pair (FLP) character that can heterolytically split H−H, Si−H and O−H bonds. Cleavage of H2 and Et3SiH affords ion pairs [Mo(NtBu)(NHtBu)(LR)2][HB(C6F5)3] (R=H 2 a ; R=CF3 2 b ) composed of a Mo(VI) amido imido cation and a hydridoborate anion, while reaction with H2O leads to [Mo(NtBu)(NHtBu)(LR)2][(HO)B(C6F5)3] (R=H 3 a ; R=CF3 3 b ). Ion pairs 2 a and 2 b are catalysts for the hydrosilylation of aldehydes with triethylsilane, with 2 b being more active than 2 a . Mechanistic elucidation revealed insertion of the aldehyde into the B−H bond of [HB(C6F5)3]. We were able to isolate and fully characterize, including by single-crystal X-ray diffraction analysis, the inserted products Mo(NtBu)(NHtBu)(LR)2][{PhCH2O}B(C6F5)3] (R=H 4 a ; R=CF3 4 b ). Catalysis occurs at [HB(C6F5)3] while [Mo(NtBu)(NHtBu)(LR)2]+ (R=H or CF3) act as the cationic counterions. However, the striking difference in reactivity gives ample evidence that molybdenum cations behave as weakly coordinating cations (WCC).  相似文献   

7.
Reactions of PdRR′(η1-dppm)2 (R = R′= C6F5 or C6Cl5; R = C6F5, R′= Cl; dppm = Ph2PCH2PPh2) with the gold derivatives ClAu(tht), C6F5Au(tht), (C6F5)3Au(tht) or O3ClOAuPPh3 (tht = tetrahydrothiophen) in appropriate ratios yield the bi- or tri-nuclear complexes PdRR′(dppm)2AuCl, PdRR′(dppm)2Au(C6F5); PdRR′(dppm)2Au(C6F5)3; PdRR′(dppmAuCl)2; PdRR′(dppmAuC6F5)2; PdRR′[dppmAu(C6F5)3]2, [PdRR′(dppm)2Au]X (X = ClO4 or BPh4); [PPh3Au(dppm)Pd(C6F5)2(dppm)AuCl]ClO4 or [PPh3 Au(dppm)Pd(C6F5)2(dppm)Au(C6F5)3]ClO4. The structure of trans-Pd(C6F5)2[dppmAu(C6F5)]2 has been determined by X-ray diffraction.  相似文献   

8.
The dimesitylpropargylphosphanes mes2P?CH2?C≡C?R 6 a (R=H), 6 b (R=CH3), 6 c (R=SiMe3) and the allene mes2P?C(CH3)=C=CH2 ( 8 ) were reacted with Piers’ borane, HB(C6F5)2. Compound 6 a gave mes2PCH2CH=CH(B(C6F5)2] ( 9 a ). In contrast, addition of HB(C6F5)2 to 6 b and 6 c gave mixtures of 9 b (R=CH3) and 9 c (R=SiMe3) with the regioisomers mes2P?CH2?C[B(C6F5)2]=CRH 2 b (R=CH3) and 2 c (R=SiMe3), respectively. Compounds 2 b , c underwent rapid phosphane/borane (P/B) frustrated Lewis pair (FLP) reactions under mild conditions. Compound 2 c reacted with nitric oxide (NO) to give the persistent FLP NO radical 11 . The systems 2 b , c cleaved dihydrogen at room temperature to give the respective phosphonium/hydridoborate products 13 b , c . Compound 13 c transferred the H+/H? pair to a small series of enamines. Compound 13 c was also a metal‐free catalyst (5 mol %) for the hydrogenation of the enamines. The allene 8 reacted with B(C6F5)3 to give the zwitterionic phosphonium/borate 17 . The ‐PPh2‐substituted mes2P‐propargyl system 6 d underwent a typical 1,2‐P/B‐addition reaction to the C≡C triple bond to form the phosphetium/borate zwitterion 20 . Several products were characterized by X‐ray diffraction.  相似文献   

9.
[Pd(C6F5)2(CNR)2] (R = Cy, But, p-MeC6H4 (p-Tol)) react with [PdCl2(NCPh)2] to give [Pd2(μ-Cl)2(C6F5)2(CNR)2]. In refluxing benzene insertion of isocyanide into the C6F5Pd bonds occurs only for R = p-Tol, to give a imidoyl bridged polynuclear complex cis-[Pd2 (μ-Cl)2[μ-C(C6F5) = N(Tol-p)]2n]. This complex reacts with (a) Tl(acac) to give [Pd2{μ-C(C6F5) = N(Tol-p)}2(acac)2]; (b) neutral monodentate ligands to afford dimeric complexes [Pd2{μ-C(C6F5) = N(Tol-p)}2Cl2L2] (L = NMe3, py, 4-Me-py, SC4H8), and (c) isocyanides to give insoluble complexes of the same composition which are thought to be polymeric, [Pd(CNR)Cl{μ-C(C6F5) = N(p-Tol)}]n (R = p-Tol, Me, But). Thermal decomposition of cis-[Pd2 (μ-Cl)2 [μ-C(C6F5) = N( p-Tol)]2n] gives the diazabutadiene species (p-Tol)NC(C6F5)C(C6F5)N(p-Tol) in high yield.  相似文献   

10.
19F NMR spectra of 1,2- dimethoxyethane solutions of Na- and Li- salts of polyfluorinated carbanions [p - RC6F4C(CN)C6F4R′-p] Na+ (Li+) and of their neutral precursors p-RC6F4CH(CN)C6F4R′-p / R  F or CF3 and R′= CF3, CF2CF3, CF(CF3)2 and C(CF3)3/ have been studied. The values of changes in the chemical shifts of fluorine atoms in the ring and the side chain are practically the same when going from the precursor to carbanion with the perfluoroalkyl group being varied. This gave grounds to conclude that the electronic effect of the perfluoroalkyl groups is rather similar. The 19F NMR method has revealed no differences in the predominant mechanism of the negative charge distribution by these groups.  相似文献   

11.
The reaction of Cp′(CpB)ZrCl2 [CpB5-C5H4B(C6F5)2] with LiNHCMe3 gave Cp′(CpB)(μ-NHCMe3)ZrCl, with a constrained-geometry type Cp---B---N chelate ligand. The 19F-NMR spectrum of the zirconium complexes, as well as that of the titanium analogue, reveals C---FH---N hydrogen bonding to one of the ortho-F atoms of a C6F5 ring, strong enough to persist in solution at room temperature. The reaction of Cp′(CpB)TiCl2 with LiPPh2 affords the Cp---B---P chelate complex Cp′(CpB)(μ-PPh2)TiCl, the first example of a crystallographically characterised Ti(IV) phosphido compound. A 19F-NMR study of a number of adducts of B(C6F5)3 with prim- and sec-amines demonstrates the importance of intramolecular hydrogen bonding to C6F5 in this class of compounds, while there are no such interactions in B(C6F5)3(PHR2) (R=Cy, Ph). The crystal structures of Cp′(CpB)(μ-PPh2)TiCl, B(C6F5)3(NHMe2) and B(C6F5)3(PHCy2) are reported.  相似文献   

12.
In the reaction of C5H5 Co(C3F7)(CO)I with the Schiff base NN′, derived from S-(-)-?-phenylethylamine and pyridine carbaldehyde-2, the salt [C5H5Co(C3F7)NN′]+ I? (Ia,b) is formed, which can be transformed to [C5H5 Co(C3F7)NN′]+ PF6? (IIa,b). The sodium salt Na+ [NN″]? of the Schiff base, derived from S-(-)-α-phenylethylamine and pyrrol carbaldehyde-2, in the reaction with C5H5 C0(C3F7)(CO)I yields the neutral complex C5H5 Co(C3F7)NN″ (IIIa,b). The diastereoisomeric pairs IIa,b and IIIa,b are separated by fractional crystallisation and chromatography respectively into the optically pure components which differ in their 1H NMR spectra. The IR, UV, CD, mass spectra and optical rotations of the new compounds IIa, IIb, IIIa and IIIb are compared.  相似文献   

13.
Reaction of CsF with ClF3 leads to Cs[Cl3F10]. It contains a molecular, propeller‐shaped [Cl3F10]? anion with a central μ3‐F atom and three T‐shaped ClF3 molecules coordinated to it. This anion represents the first example of a heteropolyhalide anion of higher ClF3 content than [ClF4]? and is the first Cl‐containing interhalogen species with a μ‐bridging F atom. The chemical bonds to the central μ3‐F atom are highly ionic and quite weak as the bond lengths within the coordinating XF3 units (X = Cl, and also calculated for Br, I) are almost unchanged in comparison to free XF3 molecules. Cs[Cl3F10] crystallizes in a very rarely observed A[5]B[5] structure type, where cations and anions are each pseudohexagonally close packed, and reside, each with coordination number five, in the trigonal bipyramidal voids of the other.  相似文献   

14.
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  相似文献   

15.
Organofluoric compounds are electrolyzed in a diaphragmless cell filled with aprotic solvent containing trimethylchlorosilane. The following substances are trimethylsilylated in the electrolysis: C6F6, C6F5CI, C6F5H, C6F5CF3, C5F5N, CFC1=CFC1, and CF2=CFBr, with the introduction of one trimethylsilyl group. The silylation mechanism is established. In some case, the silylation products’ yield is increased on a copper cathode.  相似文献   

16.
Tetraalkylammonium salts [R3RN]+X (R=R, XCH3, Cl; C2H5, Br; C3H7, Br; C4H9, H2PO4; C5H11 Br; R, R, XCH3, C16H33, Br) were investigated as ion-pairing reagents for the reversed-phase ion-pair chromatographic separation of selenite and selenate. Other chromatographic parameters such as composition and pH of the mobile phase and concentration of the ion-pairing reagent were also investigated. The compatibility of the proposed chromatographic procedures with various selenium-specific detectors is discussed. The absolute detection limits were found to be 31 ng Se for selenite and 51 ng Se for selenate (100 l injection) with a solution of 5 mM tetrabutylammonium dihydrogen phosphate in 5050 (v/v) methanol/water as mobile phase at a flow rate of 1 ml/min when a flame atomic absorption spectrometer was used as detector. The HPLC/FAAS system was employed for the determination of selenite in solutions serving as selenium supplement for animals.  相似文献   

17.
35Cl NQR spectra of pentafluorophenylchloromethanes C6F5CH(R)Cl (R = H, CH3, Cl, COOC2H5, C6F5) have been studied to obtain information on the electronic influence of the C6F5 group. On the basis of the data thus obtained and literature data, the electronic influence of the C6F5 group is discussed.  相似文献   

18.
Chloride abstraction from [{M(η3 --- C3H5)Cl}n] (M = Pt, n = 4 or M = Pd, n = 2) by (NBu4)2[cis-Pt(C6F5)2(CCSiMe3)2] (1) gives rise to novel homo- and hetero-dinuclear zwitterionic derivatives (NBu4) [{cis-Pt(C6F5)2(CCSiMe3)2}M(η3-C3H5)] (M = Pt 2; M = Pd 3) which are formed by a M(η3-allyl)+ unit attached to both alkynyl ligands of the {cis-Pt(C6F5)2(CCSiMe3)2}2− fragment. The structure of 3 has been established by X-ray diffraction.  相似文献   

19.
The determination of four volatile halocarbons (CHCl3, CCl4, C2HCl3 and C2Cl4) in water by headspace liquid-phase microextraction (HS-LPME) with gas chromatography using a micro electron capture detector (GC-μECD) is described. The effects of the type and volume of the extraction solvent, headspace volume, stirring rate, extraction temperature and time and ionic strength on the extraction performance are investigated and optimized. The developed protocol yields a linear calibration curve in the concentration range from 0.05 to 50 µg L?1 for the target analytes; the detection limits ranged from 0.003 to 0.146 µg L?1 and the relative standard deviation (R.S.D.) values below 8.45%. The results demonstrate that HS-LPME followed with GC-μECD is a simple and reliable technique for the determination of volatile halocarbons in water samples.  相似文献   

20.
New Complex Fluorides with Ag2+ and Pd2+: NaMIIZr2F11 (MII = Ag, Pd) and AgPdZr2F11 For the first time single crystals of NaAgZr2F11, NaPdZr2F11 and AgPdZr2F11 have been obtained and investigated by X-ray methods. The isotypic compounds NaMIIZr2F11 (MII = Ag, Pd) crystallize triclinic, spcgr. P1 ? C (No. 2) with a = 780.9, b = 570.0, c = 583.2 pm, α = 106.1°, β = 112.2°, γ = 97.9° (NaPdZr2F11), AgPdZr2F11 is monoclinic, spcgr. C2/m? C2h (No. 12) with a = 935.1, b = 699.1, c = 780.1 pm, β = 115.7°, Z = 2 (Four circle diffractometer data, Siemens AED 2). Their structure is closeley related to the Ag3Hf2F14-type of structure.  相似文献   

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