全氟卤代烷在氯磺酸中的电化学反应

本文报道了以氯磺酸钾为电解质, 铂为电极, 进行氯磺酸的阳极氧化, 产生过氧二磺酰氯, 并和阳极池内α,ω-氯磺含氟烷进行反应, 生成相应的氯磺酸酯, 反应主要副产物为α,ω-二氯全氟烷, 在阳极有大量氢气逸出, 并得到碘。     

全氟和多氟烷基磺酸的研究 XI: 全氟3-氧杂戊磺酸全氟苯酯的合成及其和亲核试剂的反应

Pentafluorophenyl and p-chlorotetrafluorophenyl-3- oxaperfluoroalkanesulfonates XCF2CF2OCF2CF2SO3C6F4Y (1) (Y=F, p-Cl) were synthesized by the reaction of 3-oxaperfluoroalkanesulfonyl fluoride with the corresponding sodium phenoxide in good yield. 1 reacted with various nucleophilic reagents more readily than phenyl perfluoroalkanesulfonates. The reactivity of nucleophiles toward 1 is parallel to the pKa values of their corresponding acids. All nucleophiles used (except C6H5S^-) attacked sulfur of 1 giving RfSO2Nu. Treatment of 1 with CH3CO^-2 produced perfluorophenyl acetate. When equivalent amount of KF was added to the reaction mixture the yield of the acetate decreased and main product was acetyl fluoride. This showed that the reaction followed the course of intermediary mixed anhydride formed through the attack of CH3CO^-2 on sulfur of 1. But when 1 was treated with ArS^- the only reaction occurred was C-O scission of the sulfenate by the nucleophilic attack of ArS^- on the fluorinated benzene ring to give the totrasubstituted perfluorobenzene, 1, 2, 4, 5-C6F2 (SAr)4. In contrast to the nucleophilic reaction of the mono-substituted pentafluorobenzene it was shown that in all reactions with nucleophiles para or ortho di-substituted compounds such as ReSO3C6F4Nu were not found.     

The π-acceptor effect in the substitution reactions of tridentate N-donor ligand complexes of platinum(ii): a detailed kinetic and mechanistic study

The nucleophilic substitution reactions of complexes [Pt{4'-(2'-CH(3)-phenyl)-2,2':6',2'-terpyridine}Cl]CF(3)SO(3), [CH(3)PhPtCl], [Pt{4'-(2'-CH(3)-phenyl)-6-(3'-isoquinoyl)-2,2'bipyridine}Cl]SbF(6), [CH(3)PhisoqPtCl], [Pt{2-(2'-pyridyl)-1,10-phenanthroline}Cl]Cl, [pyPhenPtCl], and [Pt(terpyridine)Cl](+), [PtCl] with a series of nucleophiles: thiourea (TU), N,N-dimethylthiourea (DMTU), N,N,N,N-tetramethylthiourea (TMTU), I(-), Br(-), and SCN(-) were studied in 0.1 M LiCF(3)SO(3) in methanol (in the presence of 10 mM LiCl). The reactivity of the investigated complexes follows the order pyPhenPtCl > PtCl > CH(3)PhPtCl > CH(3)PhisoqPtCl. The lability of the chloride ligand is dependent on the strength of π-backbonding properties of the spectator ligands around the platinum centre. The experimental data is strongly supported by DFT calculations. The dependence of the second-order rate constants on concentration of the nucleophiles as well as the large negative values reported for the activation entropy (ΔS(?)) confirmed an associative mechanism of substitution.     

C-H cleavage and double alkyl additions to the disulfido ligand in dicyanido-bridged Ru2S2 complexes

Novel dicyanido-bridged dicationic RuIIISSRuIII complexes [{Ru(P(OCH3)3)2}2(mu-S2)(mu-X)2{mu-m-C6H4(CH2CN)2}](CF3SO3)2 (4, X=Cl, Br) were synthesized by the abstraction of the two terminal halide ions of [{RuX(P(OCH3)3)2}2(mu-S2)(mu-X)2] (1, X=Cl, Br) followed by treatment with m-xylylenedicyanide. 4 reacted with 2,3-dimethylbutadiene to give the C4S2 ring-bridged complex [{Ru(P(OCH3)3)2}2{mu-SCH2C(CH3)=C(CH3)CH2S}(mu-X)2{mu-m-C6H4(CH2CN)2}](CF3SO3)2 (6, X=Cl, Br). In addition, 4 reacted with 1-alkenes in CH3OH to give alkenyl disulfide complexes [{Ru(P(OCH3)3)2}2{mu-SS(CH2C=CHR)}(mu-Cl)2{mu-m-C6H4(CH2CN)2}](CF3SO3) (7: R=CH2CH3, 9: R=CH2CH2CH3) and alkenyl methyl disulfide complexes [{Ru(P(OCH3)3)2}2{mu-S(CH3)S(CH2C=HR)}(mu-Cl)2{mu-m-C6H4(CH2CN)2}](CF3SO3)2 (8: R=CH2CH3, 10: R=CH2CH2CH3) via the activation of an allylic C-H bond followed by the elimination of H+ or condensation with CH3OH. Additionally, the reaction of 4 with 3-penten-1-ol gave [{Ru(P(OCH3)3)2}2{mu-SS(CH2C=CHCH2OH)}(mu-Cl)2{mu-m-C6H4(CH2CN)2}](CF3SO3) (11) via the elimination of H+ and [{Ru(P(OCH3)3)2}2(mu-SCH2CH=CHCH2S)(mu-Cl)2{mu-m-C6H4(CH2CN)2}](CF3SO3)2 (12) via the intramolecular elimination of a H2O molecule. 12 was exclusively obtained from the reaction of 4 with 4-bromo-1-butene.     

Theoretical dynamic studies on the reactions of CH3C(O)CH3-nCl(n) (n = 0-3) with the chlorine atom

The theoretical investigations were performed on the reaction mechanisms for the title reactions CH(3)C(O)CH(3) + Cl --> products (R1), CH(3)C(O)CH(2)Cl + Cl --> products (R2), CH(3)C(O)CHCl(2) + Cl --> products (R3), and CH(3)C(O)CCl(3) + Cl --> products (R4) by ab initio direct dynamics approach. Two different reaction channels have been found: abstract of the H atom from methyl (--CH(3)) group or chloromethyl (--CH(3-n)Cl(n)) group of chloroacetone and addition of a Cl atom to the carbon atom of the carbonyl group of chloroacetone followed by methyl or chloromethyl eliminations. Because of the higher potential energy barrier, the contribution of addition-elimination reaction pathway to the total rate constants is very small and thus this pathway is insignificant in atmospheric conditions. The rate constants for the H-abstraction reaction channels are evaluated by using canonical variational transition state theory incorporating with the small-curvature tunneling correction. Theoretical overall rate constants are in good agreement with the available experimental values and decrease in the order of k(1) > k(2) > k(3) > k(4). The results indicate that for halogenated acetones the substitution of halogen atom (F or Cl) leads to the decrease in the C--H bond reactivity and more decrease of reactivity is caused by F-substitution.     

Ruthenium-catalyzed aromatization of enediynes via highly regioselective nucleophilic additions on a pi-alkyne functionality. A useful method for the synthesis of functionalized benzene derivatives

TpRu(PPh3)(CH3CN)2 PF6 (10 mol %) catalyst effected the nucleophilic addition of water, alcohols, aniline, acetylacetone, pyrroles, and dimethyl malonate to unfunctionalized enediynes under suitable conditions (100 degrees C, 12-24 h) and gave functionalized benzene products in good yields. In this novel cyclization, nucleophiles very regioselectively attack the internal C1' alkyne carbon of enediynes to give benzene derivatives as a single regioisomer. Experiments with methoxy substituents exclude the possible involvement of naphthyl cations as reaction intermediates in the cyclization of (o-ethynylphenyl) alkynes. Deuterium-labeling experiments indicate that the catalytically active species is ruthenium-pi-alkyne rather than ruthenium-vinylidene species. This hypothesis is further confirmed by the aromatization of o-(2'-iodoethynyl)phenyl alkynes with alcohols. We propose a nucleophilic addition/insertion mechanism for this nucleophilic aromatization on the basis of a series of experiments.     

A Novel synthesis of 2-functionalized benzofurans by palladium-catalyzed cycloisomerization of 2-(1-hydroxyprop-2-ynyl)phenols followed by acid-catalyzed allylic isomerization or allylic nucleophilic substitution

A novel two-step synthesis of 2-hydroxymethylbenzofurans 3 and 2-alkoxymethylbenzofurans 4-6, based on palladium-catalyzed cycloisomerization of 2-(1-hydroxyprop-2-ynyl)phenols 1 under basic conditions to give 2-methylene-2,3-dihydrobenzofuran-3-ols 2, followed by acid-catalyzed isomerization or allylic nucleophilic substitution with alcohols as nucleophiles, is reported. Cycloisomerization reactions leading to 2 (80-98% yields) were carried out at 40 degrees C in MeOH as the solvent, in the presence of a base and catalytic amounts of PdX2 + 2KX (X = Cl, I). Isomerization reactions of 2 readily occurred at 25-60 degrees C in DME as the solvent, with H2SO4 as the proton source, to give 2-hydroxymethylbenzofurans 3 in 65-90% yields. In a similar manner, allylic nucleophilic substitution reactions of 2 with ROH as nucleophiles [carried out at 25-40 degrees C in ROH (R = Me) or ROH-DME mixtures (R = Bu, Bn) in the presence of H2SO4] afforded 2-alkoxymethylbenzofurans 4, 5, and 6 (R = Me, Bu, and Bn, respectively), in 65-98% yields.     

Free energies for degradation reactions of 1,2,3-trichloropropane from ab initio electronic structure theory

Electronic structure methods were used to calculate the gas and aqueous phase reaction energies for reductive dechlorination (i.e., hydrogenolysis), reductive β-elimination, dehydrochlorination, and nucleophilic substitution by OH? of 1,2,3-trichloropropane. The thermochemical properties ΔH(f)°(298.15 K), S°(298.15 K, 1 bar), and ΔG(S)(298.15 K, 1 bar) were calculated by using ab initio electronic structure calculations, isodesmic reactions schemes, gas-phase entropy estimates, and continuum solvation models for 1,2,3-trichloropropane and several likely degradation products: CH3?CHCl?CH2Cl, CH2Cl?CH2?CH2Cl, C?H2?CHCl?CH2Cl, CH2Cl?C?H?CH2Cl, CH2═CCl?CH2Cl, cis-CHCl═CH?CH2Cl, trans-CHCl═CH?CH2Cl, CH2═CH?CH2Cl, CH2Cl?CHCl?CH2OH, CH2Cl?CHOH?CH2Cl, CH2═CCl?CH2OH, CH2═COH?CH2Cl, cis-CHOH═CH?CH2Cl, trans-CHOH═CH?CH2Cl, CH(═O)?CH2?CH2Cl, and CH3?C(═O)?CH2Cl. On the basis of these thermochemical estimates, together with a Fe(II)/Fe(III) chemical equilibrium model for natural reducing environments, all of the reactions studied were predicted to be very favorable in the standard state and under a wide range of pH conditions. The most favorable reaction was reductive β-elimination (ΔG(rxn)° ≈ ?32 kcal/mol), followed closely by reductive dechlorination (ΔG(rxn)° ≈ ?27 kcal/mol), dehydrochlorination (ΔG(rxn)° ≈ ?27 kcal/mol), and nucleophilic substitution by OH? (ΔG(rxn)° ≈ ?25 kcal/mol). For both reduction reactions studied, it was found that the first electron-transfer step, yielding the intermediate C?H2?CHCl?CH2Cl and the CH2Cl?C?H?CH2Cl species, was not favorable in the standard state (ΔG(rxn)° ≈ +15 kcal/mol) and was predicted to occur only at relatively high pH values. This result suggests that reduction by natural attenuation is unlikely.     

Gas phase reactions of NH2Cl with anionic nucleophiles: Nucleophilic substitution at neutral nitrogen

Reactions of chloramine, NH2Cl, with HO-, RO- (R = CH3, CH3CH2, CH3CH2CH2, C6H5CH2, CF3CH2), F- , HS- , and Cl- have been studied in the gas phase using the selected ion flow tube technique. Nucleophilic substitution (S(N)2) at nitrogen to form Cl- has been observed for all the nucleophiles. The reactions are faster than the corresponding S(N)2 reactions of methyl chloride; the chloramine reactions take place at nearly every collision when the reaction is exothermic. The thermoneutral identity S(N)2 reaction of NH2Cl with Cl-, which occurs approximately once in every 100 collisions, is more than two orders of magnitude faster than the analogous reaction of CH3Cl. The significantly enhanced S(N)2 reactivity of NH2Cl is consistent with a previous theoretical prediction that the barrier height for the S(N)2 identity reaction at nitrogen is negative relative to the energy of the reactants, whereas this barrier height for reaction at carbon is positive. Competitive proton abstraction to form NHCl- has also been observed with more highly basic anions (HO-, CH3O-, and CH3CH2O-), and this is the major reaction channel for HO- and CH3O-. Acidity bracketing determines the heat of deprotonation of NH2Cl as 374.4 +/- 3.0 kcal mol(-1).     

多氟芳烃的亲核反应II: 一氯五氟苯的亲核环化

本文报道一氯五氟苯与双官能团亲核试剂反应制备环化产物的研究结果, 发现应用NaH-DMF体系制备醇钠, 有利于亲核反应的顺利进行, 环化产物产率有较大幅度提高.     

An experimental and computational study on the effect of Al(OiPr)3 on atom-transfer radical polymerization and on the catalyst-dormant-chain halogen exchange

Compound Al(OiPr)3 is shown to catalyze the halide-exchange process leading from [Mo(Cp)Cl2(iPrN=CH-CH=NiPr)] and CH3CH(X)COOEt (X=Br, I) to the mixed-halide complexes [Mo(Cp)ClX(iPrN=CH-CH=NiPr)]. On the other hand, no significant acceleration is observed for the related exchange between [MoX3(PMe3)3] (X=Cl, I) and PhCH(Br)CH3, by analogy to a previous report dealing with the Ru(II) complex [RuCl2(PPh3)3]. A DFT computation study, carried out on the model complexes [Mo(Cp)Cl2(PH3)2], [MoCl3(PH3)3], and [RuCl2(PH3)3], and on the model initiators CH3CH(Cl)COOCH3, CH3Cl, and CH3Br, reveals that the 16-electron Ru(II) complex is able to coordinate the organic halide RX in a slightly exothermic process to yield saturated, diamagnetic [RuCl2(PH3)3(RX)] adducts. The 15-electron [MoCl3(PH3)3] complex is equally capable of forming an adduct, that is, the 17-electron [MoCl3(PH3)3(CH3Cl)] complex with a spin doublet configuration, although the process is endothermic, because it requires an energetically costly electron-pairing process. The interaction between the 17-electron [Mo(Cp)Cl2(PH3)2] complex and CH3Cl, on the other hand, is repulsive and does not lead to a stable 19-electron adduct. The [RuCl2(PH3)3(CH3X)] system leads to an isomeric complex [RuClX(PH3)3(CH3Cl)] by internal nucleophilic substitution at the carbon atom. The transition state of this process for X=Cl (degenerate exchange) is located at lower energy than the transition state required for halogen-atom transfer leading to [RuCl3(PH3)3] and the free radical CH3. On the basis of these results, the uncatalyzed halide exchange is interpreted as the result of a competitive S(N)i process, whose feasibility depends on the electronic configuration of the transition-metal complex. The catalytic action of Al(OiPr)3 on atom-transfer radical polymerization (and on halide exchange for the 17-electron half-sandwich Mo(III) complex) results from a more favorable Lewis acid-base interaction with the oxidized metal complex, in which the transferred halogen atom is bound to a more electropositive element. This conclusion derives from DFT studies of the model [Al(OCH3)3]n (n=1,2,3,4) compounds, and on the interaction of Al(OCH3)3 with CH3Cl and with the [Mo(Cp)Cl3(PH3)2] and [RuCl3(PH3)3] complexes.     

Electronic and medium effects on the rate of arene C [bond] H activation by cationic Ir(III) complexes

A detailed mechanistic study of arene C [bond] H activation in CH(2)Cl(2) solution by Cp(L)IrMe(X) [L = PMe(3), P(OMe)(3); X = OTf, (CH(2)Cl(2))BAr(f); (BAr(f) = B[3,5-C(6)H(3)(CF(3))(2)](4))(-)] is presented. It was determined that triflate dissociation in Cp(L)IrMe(OTf), to generate tight and/or solvent-separated ion pairs containing a cationic iridium complex, precedes C [bond] H activation. Consistent with the ion-pair hypothesis, the rate of arene activation by Cp(L)IrMe(OTf) is unaffected by added external triflate salts, but the rate is strongly dependent upon the medium. Thus the reactivity of Cp(PMe(3))IrMe(OTf) can be increased by almost 3 orders of magnitude by addition of (n-Hex)(4)NBAr(f), presumably because the added BAr(f) anion exchanges with the OTf anion in the initially formed ion pair, transiently forming a cation/borate ion pair in solution (special salt effect). In contrast, addition of (n-Hex)(4)NBAr(f) to [CpPMe(3)Ir(Me)CH(2)Cl(2)][BAr(f)] does not affect the rate of benzene activation; here there is no initial covalent/ionic pre-equilibrium that can be perturbed with added (n-Hex)(4)NBAr(f). An analysis of the reaction between Cp(PMe(3))IrMe(OTf) and various substituted arenes demonstrated that electron-donating substituents on the arene increase the rate of the C [bond] H activation reaction. The rate of C(6)H(6) activation by [Cp(PMe(3))Ir(Me)CH(2)Cl(2)][BAr(f)] is substantially faster than [Cp(P(OMe)(3))Ir(Me)CH(2)Cl(2)][BAr(f)]. Density functional theory computations suggest that this is due to a less favorable pre-equilibrium for dissociation of the dichloromethane ligand in the trimethyl phosphite complex, rather than to a large electronic effect on the C [bond] H oxidative addition transition state. Because of these combined effects, the overall rate of arene activation is increased by electron-donating substituents on both the substrate and the iridium complex.     

二苯并-18-冠-6的氯甲基化及其在交联聚乙烯醇微球表面的固载化

在Lewis酸催化剂存在下,1,4-二氯甲氧基丁烷对冠醚二苯并-18-冠-6(1)进行氯甲基化修饰使其转变成氯甲基化冠醚(2),其结构经1HNMR,13C NMR,IR及MS表征。2与交联聚乙烯醇(CPVA)微球表面的羟基发生亲核取代反应实现冠醚的固载化,制得固载有冠醚的功能微球(3)。实验结果表明,1的氯甲基化反应易于进行,在两个苯环上分别发生了对称的氯甲基化反应,2为对称的四取代产物。通过2的氯甲基与CPVA的羟基之间的亲核取代反应,1可容易地化学固载到CPVA表面。     

乙烯-丙烯共聚物磺酸盐离聚物的研究——Ⅰ.乙烯-丙烯共聚物及其氯磺化反应

本文用钛系高效催化剂合成了四种乙烯-丙烯共聚物,测定了共聚物的单体组成、序列结构分布、分子量和结晶度.在考察了引发剂和氯磺化试剂对氯磺化反应影响的基础上,制备了不同磺化度的氯磺化乙丙共聚物,并用~(13)C-NMR分析其化学结构,表明共聚物分子链上CH没有发生反应,CH_3只被-SO_2Cl取代,而CH_2可被-SO_2Cl或-Cl取代.     

Hydrogen/chlorine exchange reactions of gaseous carbanions

Gas-phase reactions of three typical carbanions CH(2)NO(2)(-), CH(2)CN(-), and CH(2)S(O)CH(3)(-) with the chloromethanes CH(2)Cl(2), CHCl(3), and CCl(4), examined by tandem mass spectrometry, show a novel hydrogen/chlorine exchange reaction. For example, reaction between the nitromethyl anion CH(2)NO(2)(-) and carbon tetrachloride CCl(4) forms the ion CHClNO(2)(-). The suggested reaction mechanism involves nucleophilic attack by CH(2)NO(2)(-) at the chlorine of CCl(4) followed by proton transfer within the resulting complex [CH(2)ClNO(2) + CCl(3)(-)] to form CHClNO(2)(-) and CHCl(3). Two other carbanions CH(2)CN(-) and CH(2)S(O)CH(3)(-) also undergo the novel hydrogen/chlorine exchange reactions with CCl(4) but to a much smaller extent, their higher nucleophilicities favoring competitive nucleophilic attack reactions. Proton abstraction is the exclusive pathway in the reactions of these carbanions with CHCl(3). While CH(2)CN(-) and CH(2)S(O)CH(3)(-) promote mainly proton abstraction and nucleophilic displacement in reactions with CH(2)Cl(2), CH(2)NO(2)(-) does not react.     

Synthesis and characterization of β-diketiminato complexes of antimony (III) halides

Treatment of SbX₃ (X = Br, Cl) with DippnacnacLi (Dippnacnac = [{N(C₆H₃ⁱPr₂2,6)C(Me)}₂CH]⁻) or Mesnacnac (Mesnacnac = [{N(Mes)C(Me)}₂CH]⁻, Mes = 2,4,6, trimethyl benzene) affords different products that are dependent on the stoichiometry of the reaction and the halide precursor. When DippnacnacLi is reacted with SbBr₃, C-H activation of the ligand backbone is observed and an asymmetric, bridged bromide dimer is isolated. In comparison, the reaction of SbCl₃ with MesnacnacLi affords monomeric MesnacnacSbCl₂. The solid-state structures were determined using X-ray crystallography.     

Reactivity of an anionic Pd(II) metallacycle with CH2X2 (X=Cl, Br, I): formal insertion of methylene into a Pd-C(aryl) bond

Whereas the reaction of the anionic palladium metallacycle [K[Pd(CH2CMe2-o-C6H4)(kappa2-Tp)]] with CH2Cl2 leads to the isolation of the stable Pd(IV) chloromethyl complex [Pd(CH2CMe2-o-C6H4)(kappa3-Tp)(CH2Cl)], the analogous reactions with CH2Br2 and CH2I2 give rise to the six membered metallacycles [Pd(CH2CMe2-o-C6H4(CH2))(kappa3-Tp)X](X = Br or I), as a result of the formal insertion of CH2 into the Pd-C(aryl) bond.     

Photolytic generation of benzhydryl cations and radicals from quaternary phosphonium salts: how highly reactive carbocations survive their first nanoseconds

UV irradiation (266 or 280 nm) of benzhydryl triarylphosphonium salts Ar(2)CH-PAr(3)(+)X(-) yields benzhydryl cations Ar(2)CH(+) and/or benzhydryl radicals Ar(2)CH(?). The efficiency and mechanism of the photo-cleavage were studied by nanosecond laser flash photolysis and by ultrafast spectroscopy with a state-of-the-art femtosecond transient spectrometer. The influences of the photo-electrofuge (Ar(2)CH(+)), the photo-nucleofuge (PPh(3) or P(p-Cl-C(6)H(4))(3)), the counterion (X(-) = BF(4)(-), SbF(6)(-), Cl(-), or Br(-)), and the solvent (CH(2)Cl(2) or CH(3)CN) were investigated. Photogeneration of carbocations from Ar(2)CH-PAr(3)(+)BF(4)(-) or -SbF(6)(-) is considerably more efficient than from typical neutral precursors (e.g., benzhydryl chlorides or bromides). The photochemistry of phosphonium salts is controlled by the degree of ion pairing, which depends on the solvent and the concentration of the phosphonium salts. High yields of carbocations are obtained by photolyses of phosphonium salts with complex counterions (X(-) = BF(4)(-) or SbF(6)(-)), while photolyses of phosphonium halides Ar(2)CH-PPh(3)(+)X(-) (X(-) = Cl(-) or Br(-)) in CH(2)Cl(2) yield benzhydryl radicals Ar(2)CH(?) due to photo-electron transfer in the excited phosphonium halide ion pair. At low concentrations in CH(3)CN, the precursor salts are mostly unpaired, and the photo-cleavage mechanism is independent of the nature of the counter-anions. Dichloromethane is better suited for generating the more reactive benzhydryl cations than the more polar and more nucleophilic solvents CH(3)CN or CF(3)CH(2)OH. Efficient photo-generation of the most reactive benzhydryl cations (3,5-F(2)-C(6)H(3))(2)CH(+) and (4-(CF(3))-C(6)H(4))(2)CH(+) was only achieved using the photo-leaving group P(p-Cl-C(6)H(4))(3) and the counter-anion SbF(6)(-) in CH(2)Cl(2). The lifetimes of the photogenerated benzhydryl cations depend greatly on the decay mechanisms, which can be reactions with the solvent, with the photo-leaving group PAr(3), or with the counter-anion X(-) of the precursor salt. However, the nature of the photo-leaving group and the counterion of the precursor phosphonium salt do not affect the rates of the reactions of the obtained benzhydryl cations toward added nucleophiles. The method presented in this work allows us to generate a wide range of donor- and acceptor-substituted benzhydryl cations Ar(2)CH(+) for the purpose of studying their electrophilic reactivities.     

Novel cation [N(SO2NMe3)2]+ and its synthesis and crystal structure. Dichloride of imido-bis(sulfuric) acid HN(SO2Cl)2. Part 1. Crystal structures of KN(SO2Cl)2.(1/2)CH3CN, KN(SO2Cl)2.(1/6)CH2Cl2, and [PCl4][N(SO2Cl)2

Several salts of bis(chlorosulfonyl)imide HN(SO2Cl)2 (1), namely, two solvates of its potassium salt, KN(SO2Cl)2.(1/2)CH3CN (1K1), KN(SO2Cl)2.(1/6)CH2Cl2 (1K2), and its tetrachlorophosphonium salt, [PCl4][N(SO2Cl)2] (2), were prepared and structurally characterized. The reaction of HN(SO2Cl)2 with Me3N gives the [N(SO2Cl)2]- salt of a novel cation, [N(SO2NMe3)2]+. This cation is analogous to the [HC(SO2NMe3)2]+ cation, but in contrast to the latter, it is fairly stable to hydrolysis. The salt [N(SO2NMe3)2]+[N(SO2Cl)2]- (3) can be converted into salts of other anions by being treated with diluted aqueous solutions of the respective acids, and thus NO3-, Cl-.H2O, SeO3(2-), CH3COO-, HSO4-, (COO)2(2-) salts were prepared. Treatment of 3 with concentrated HNO3 gave the [N(SO2NMe3)2]+ [O2NO-H-ONO2]- salt, and the addition of an HCl-acidified FeCl3 aqueous solution yielded the FeCl4- salt. Methanolysis resulted in the formation of MeOSO3- and [MeOSO2NSO2OMe]- salts. All salts have been characterized by chemical analysis, vibrational spectroscopy, and X-ray structure determinations.     

A computational study of the reaction of ground-state nitrogen atoms with chloromethyl radicals

A computational study of the N(4S) + CH2Cl reaction has been carried out. The first step of the reaction is the formation of an initial intermediate (NCH2Cl), which is relatively stable and does not involve any energy barrier. The two most exothermic products are those resulting from the release of a chlorine atom, H2C=N + Cl and trans-HC=NH + Cl. A kinetic study within the framework of the statistical theories suggests that the kinetically preferred product is also the most exothermic one. This is in contrast with the analogue reaction of nitrogen atoms with CH2F, where the preferred product from both thermodynamic and kinetic points of view is HFCN + H. Therefore, reactions of nitrogen atoms with chloromethyl radicals release chlorine atoms as major products. The rate coefficient for the title reaction is estimated to be about 3.09 x 10(-13) cm3 s(-1) molecule(-1) at 300 K, a value four times smaller than the rate coefficient for its fluorine analogue.