The thiolate anion as a nucleophile Part XII. Reactions of Lead(II) Benzenethiolate

The reactions of various fluoroaromatics, C₆F_6?xH_x, and C₆F₅X (X = C₆F₆, Cl, Me, NO₂, CF₃, COCl, CH₂Br, OMe, and NH₂) with lead(II) benzenethiolate in DMF have been examined. Lead thiolate acted as an excellent source of benzenethiolate anions and displacement of fluorine, chlorine or the nitro group was observed. The new products have been characterized by elemental analysis, and NMR (H?1 and F?19), infrared and mass spectroscopy.     

Nitroxide chemistry. Part XVII [1]. Reaction of bistrifluoromethyl nitroxide with some halogenoalkanes and related alkenes

The mono (bistrifluoromethylamino-oxy)alkanes (CF₃)₂NOCXYZ (X = Y = F, Z = Cl; X = H, Y = F or Cl, Z = CH₃; X = Y = F, Z = CH₃; X = H, Y = Cl or Br, Z = CF₃; X = Cl, Y = Br, Z = CF₃) have been synthesised by treatment of appropriate halogenoalkanes, CHXYZ, with bistrifluoromethyl nitroxide. The 1,2-bis(bistrifluoromethylamino-oxy)alkanes (CF₃)₂NOCH₂CXYON(CF₃)₂ were obtained as by-products in the reactions involving the ethanes CH₃CHXY (X = H, Y = F or Cl; X = Y = F); these products, like their analogues (CF₃)₂NOCHFCF₂ON(CF₃)₂ and (CF₃)₂NOCH₂CCl₂ON(CF₃)₂, were also prepared $\text{via}$ attack of bistrifluoromethyl nitroxide on the corresponding ethenes.     

Darstellung und charakterisierung von trifluormethylthio-cyclopropanen

The reactions of dihalogenocarbenes (CX₂, X = F, Cl, Br) with CF₃SCHCH₂ or (CF₃S)₂CCH₂ yield the corresponding substituted cyclopropanes. 1,1-Dibromo-2-trifluoromethylthio- or 1,1-dibromo- 2,2-bis(trifluoromethylthio)cyclopropanes react with (nC₄H₉)₃SnH to form trifluoromethylthio - or 1,1-bis(trifluoromethylthio)cyclopropane in good yields. Physical and spectroscopic data of the new substances are provided.     

Site directed synthesis of mono and disubstituted SF5-polyfluoroalkyl benzenes

A novel method for the preparation of o-, m-, p-SF₅CF₂CFYC₆H₄X (Y = Br, F and X = m-Br, p-Br, Cl, CH₃, CF₃, NO₂, o-NO₂, F, CF₃, CH(CH₃)₂) derivatives was devised by a two-step reaction: SF₅Br-addition to o-, m-, p-CF₂CFC₆H₄X followed by reaction of AgBF₄ with the o-, m-, p-SF₅CF₂CFBrC₆H₄X adducts. Additional studies have been carried out with several derivatives and includes the preparation of SF₅CF₂C(O)C₆H₅, p-CF₃CFBrC₆H₄NO₂, SF₅CF₂CF₂C₆H₃(NO₂)₂, SF₅CF₂CF₂C₆H₃(NH₂)₂, and an SF₅CF₂CF₂-containing polyimide and dye. The complete characterization (IR, NMR, and MS) of these compounds is given.     

Computational Analysis of Mesomerism in para-Substituted mer-NCN Pincer Platinum(II) Complexes,Including its Relationships with Hammett σp Substituent Parameters

Density Functional Theory studies of square-planar Pt^II pincer structures, (4-Z-NCN)PtCl ([4-Z-NCN]⁻=[4-Z-2,6-(Me₂NCH₂)₂C₆H₂-N,C,N]⁻, Z=H, NO₂, CF₃, CO₂H, CHO, Cl, Br, I, F, SMe, SiMe₃, tBu, OH, NH₂, NMe₂), enable characterisation of mesomerism for the pincer-Pt interaction. Relationships between Hammett σ_p substituent parameters of Z and DFT data obtained from NBO6 and AOMix computation are used to probe the interaction of the 5d_yz orbital of platinum with π-orbitals of the arene ring. Analogous computation for 2,6-(Me₂CH₂)₂C₆H₃Z (Z=H, CF₃, CHO, Cl, Br, I, F, SMe, SiMe₃, tBu, OH, NH₂) and (4-H-NCN)PtZ allows an estimation of the relative substituent effects of “(CH₂NMe₂)₂PtZ” on π-delocalisation in the pincer system.     

Unexpected formation of N-fluoroalkaneacyl anilides from the reactions of fluoroalkanesulfonyl azides with nitrobenzene and its derivatives

The thermal reactions of fluoroalkanesulfonyl azides R_fCF₂SO₂N₃1 with nitrobenzene and its derivatives XC₆H₄NO₂ (X=H, F, Cl, CF₃) gave the unexpected N-fluoroalkaneacyl anilides R_fCONHC₆H₄X (X=H, Cl, F, CF₃) in addition to fluoroalkanesulfonyl amides R_fCF₂SO₂NH₂. Under the same reaction conditions, however, nitrobenzene containing an electron-donating group RC₆H₄NO₂ (R=CH₃, OCH₃) reacted with 1 affording the corresponding N-fluoroalkanesulfonyl anilides R_fCF₂SO₂NHC₆H₃(NO₂)R. Other electron-poor benzene derivatives, such as benzaldehyde, benzoate, and acetophenone C₆H₅Y(Y=CHO, COCH₃, CO₂CH₃) all gave the meta-substituted N-fluoroalkanesulfonyl anilides R_fCF₂SO₂NHC₆H₄Y.     

Effect of the X and Y substituents on the carbonyl bond in 4-YC<Subscript>6</Subscript>H<Subscript>4</Subscript>C(O)X compounds

Mechanistic aspects of the effect of the X and Y substituents (X = Me, H, CF₃, CN, Br, Cl, F, OH, NH₂; Y = H, NMe₂, NH₂, CN, NO₂) on the carbonyl bond in 4-YC₆H₄C(O)X compounds are discussed on the basis of the ¹³C and ¹⁷O NMR data.     

The formation of the anilinium ion from the ammonium ion in the ammonia chemical ionization of substituted benzenes

Compounds C₆H₅X(X ? F, Cl, Br, NO₂, CN, OCH₃) have been studied under chemical ionization conditions with ammonia as reagent gas. A pulsed electron beam and time resolved ion collection has allowed the determination of the reaction leading to the formation of [C₆H₅NH₃]⁺ (m/z 94). [NH₄]⁺ reacts with C₆H₅X(X ? F, Cl, Br) to yield m/z 94 but C₆H₅X (X ? CN, NO₂) forms this ion only by reactions involving either [NH₃]⁺ or [C₆H₅X]⁺. C₆H₅OCH₃ does not form m/z 94.     

Synthesis of substituted biaryls via Suzuki,Stille and Hiyama cross‐coupling and homo‐coupling reactions by CN‐dimeric and monomeric ortho‐palladated catalysts

The catalytic activity of dimeric [Pd{C₆H₂(CH₂CH₂NH₂)–(OMe)₂,2,3}(μ‐Br)]₂ and monomeric [Pd{C₆H₂(CH₂CH₂NH₂)–(OMe)₂,2,3}Br(PPh₃)] complexes as efficient, stable and air‐ and moisture‐tolerant catalysts was investigated in the Suzuki, Stille and Hiyama cross‐coupling and homo‐coupling reactions of various aryl halides. Substituted biaryls were produced in excellent yields in short reaction times using catalytic amounts of these complexes. The monomeric complex was demonstrated to be more active than the corresponding dimeric catalyst for the cross‐coupling reaction of unreactive aryl bromides and chlorides. The combination of homogeneous metal catalysts and microwave irradiation gave higher yields of products in shorter reaction times. Copyright © 2013 John Wiley & Sons, Ltd.     

Synthesen und NMR‐Untersuchungen von Salzen mit den neuen Anionen [PtXn(CF3)6‐n]2— (n = 0 ‐ 5, X = F,OH, Cl,CN) und die Kristallstrukturanalyse von K2[(CF3)2F2Pt(μ‐OH)2PtF2(CF3)2]·2H2O

Syntheses and NMR Spectroscopic Ivestigations of Salts containing the Novel Anions [PtX_n(CF₃)_6‐n]^2— (n = 0 ‐ 5, X = F, OH, Cl, CN) and Crystal Structure of K₂[(CF₃)₂F₂Pt(μ‐OH)₂PtF₂(CF₃)₂]·2H₂O The first syntheses of trifluoromethyl‐complexes of platinum through fluorination of cyanoplatinates are reported. The fluorination of tetracyanoplatinates(II), K₂[Pt(CN)₄], and hexacyanoplatinates(IV), K₂[Pt(CN)₆], with ClF in anhydrous HF leads after working up of the products to K₂[(CF₃)₂F₂Pt(μ‐OH)₂PtF₂(CF₃)₂]·2H₂O. The structure of the salt is determined by a X‐ray structure analysis, P2₁/c (Nr. 14), a = 11.391(2), b = 11.565(2), c = 13.391(3)Å, β = 90.32(3)°, Z = 4, R₁ = 0.0326 (I > 2σ(I)). The reaction of [Bu₄N]₂[Pt(CN)₄] with ClF in CH₂Cl₂ generates mainly cis‐[Bu₄N]₂[PtCl₂(CF₃)₄] and fac‐[Bu₄N]₂[PtCl₃(CF₃)₃], but in contrast that of [Bu₄N]₂[Pt(CN)₆] with ClF in CH₂Cl₂ results cis‐[Bu₄N]₂[PtX₂(CF₃)₄], [Bu₄N]₂[PtX(CF₃)₅] (X = F, Cl) and [Bu₄N]₂[Pt(CF₃)₆]. In the products [Bu₄N]₂[PtX_n(CF₃)_6‐n] (X = F, Cl, n = 0—3) it is possibel to exchange the fluoro‐ligands into chloro‐ and cyano‐ligands by treatment with (CH₃)₃SiCl und (CH₃)₃SiCN at 50 °C. With continuing warming the trifluoromethyl‐ligands are exchanged by chloro‐ and cyano‐ligands, while as intermediates CF₂Cl and CF₂CN ligands are formed. The identity of the new trifluoromethyl‐platinates is proved by ¹⁹⁵Pt‐ and ¹⁹F‐NMR‐spectroscopy.     

Kinetic Parameters for Direct Atomic Substitution Reactions

Experimental data (the rate constants and activation energies) for seven reactions of direct substitution of one atom for another D + CH₃R CH₂DR + H, D + NH₃ DNH₂ + H, D + H₂O HOD + H, F + CH₃X CH₃F + X (X = F, Cl, Br, and I) involving atoms D and F and molecules C₂H₆, H₂O, NH₃, CH₃F, CH₃Cl, CH₃Br, and CH₃I are analyzed using the parabolic model of a bimolecular radical reaction. The activation energies for the thermally neutral analogs of these substitution reactions are calculated. Atomic substitution involving deuterium atoms has a lower activation energy of a thermally neutral reaction than radical abstraction or substitution.     

Reaktionen an Isocyanidverbindungen

By the reaction of FSO₂N?PCl₃ with perfluorpropionic acid FSO₂NHC(O)C₂F₅ is formed, which yields FSO₂N?C(Cl)? C₂F₅ (I) with PCl₅. The chlorine atom in (I) could be replaced by the substituents NH₂ (II) and N(C₂H₅)₂ (III). FSO₂N?C(Cl)? CF₃ reacts with AgOCN, AgSCN, unhydrous HF and 2,3-dimethylbutadiene. FSO₂N(CH₃)? C(O)F reacts with elemental fluorine under exchange of a proton against a fluorine atom to give FSO₂N(CH₂F)? C(O)F, which liberates at room temperature COF₂ and trimerises to form 1,3,5-Tris-fluorosulfonyl-s-triazine (VIII). The amides FSO₂N?C(CH₃)NH₂ and FSO₂N?C(CF₃)NH₂ react with SF₄ in the presence of NaF to yield the iminosulfur difluorides FSO₂N?C(CH₃)? NSF₂ (IX) and FSO₂N?C(CF₃)? NSF₂ (X)     

Modified cyclopentadienyl molybdenum compounds with enhanced cytotoxic activity towards MOLT‐4 leukaemia cells

A series of new cyclopentadienyl molybdenum compounds bearing substituted phenanthroline ligands [(η⁵‐C₅H₄CH₂C₆H₄X‐4)Mo(CO)₂(^N,NL)][BF₄] (X = F, Cl, Br; ^N,NL = phen, 5‐NH₂‐phen, 4,7‐Ph₂‐phen) was prepared and characterized using infrared and NMR spectroscopies. Crystal structures of [(η⁵‐C₅H₄CH₂C₆H₄F‐4)Mo(CO)₂(NCMe)₂][BF₄], [(η⁵‐C₅H₄CH₂C₆H₄X‐4)Mo(CO)₂(phen)][BF₄] (X = F, Cl, Br) and [(η⁵‐C₅H₄CH₂C₆H₄Cl‐4)Mo(CO)₂(4,7‐Ph₂‐phen)][BF₄]⋅(4,7‐Ph₂‐phen)⋅HBF₄ were determined using X‐ray diffraction analysis. Biological studies revealed a strong cytotoxic effect of the chelating ligands. Although the cytostatic effect of the halogen in the side chain of the cyclopentadienyl ring is negligible, it could be used for future post‐modification of these types of cytotoxic active molybdenum‐based compounds.     

Advances in Trifluoromethylating Phosphorus Compounds

Abstract

The System CF₃I/Me₃P is re-investigated and Me₂PCF₃, Me₄P⁺γ, (CF₃)₂PMe₃, Me₃PI₂, [Me₃(CF₃)P]⁺γ are found as products. Using CF₃Br/P(NEt₂)₃ the phosphines R¹ ₂PCF₃ and R¹P(CF₃)₂ (e.g. R¹ = Me, iPr, NEt₂) can be obtained which are precursors either for phosphoranes (e.g. 1,2λ⁵σ⁵-oxaphosphetanes) or phosphonium salts (e.g. [R¹ ₂(Me)PCF₃]⁺X^? or [R¹(Me)P(CF₃)₂X^?]. The latter are deprotonated to furnish methylene phosphoranes R¹ ₂(CH₂=)PCF₃ or R¹(CH₂=)P(CF₃)₂, reactive synthons. From CF₃Br/P(NEt₂)₃/P(OPh)₃ the phosphine P(CF₃)₃ is available, which turned out to be a potent electrophile. Amido phospites ROP(NEt₂)₂ and halides R²X (R²=CCl₂CF₃, X=Cl; R²=CF=CFCF₃, X=F; R²=C₆F₅, X=Br, I; R²=C(CF₃)₃, X=Br; R²=SCF₃, X=CF₃) undergo an ARBUZOV reaction.     

Schwingungsspektroskopische Untersuchungen an den Organohydrogensilanen (XCH2)(CH3)2SiH (X = Cl,Br, J), X(YO)2SiH (X = CH3, C2H5/Y = CH3, C2H5 … tert.-C4H9), (C6H5)2SiH2 und C6H5SiH3

Infrared and Raman Spectroscopic Investigations on the Organosubstituted Silicon Hydrides (XCH₂)(CH₃)₂SiH (X = Cl, Br, J), X(YO)₂SiH (X = CH₂, C₂H₅/Y = CH₃, C₂H₅ … tert.-C₄H₉), (C₆H₅)₂SiH₂ and C₆H₅SiH₃ Typical band splittings, specially for the SiH stretching vibration, are shown in the infrared and Raman spectra of the silicon hydrides (XCH₂)(CH₃)₂SiH (X = Cl, Br, J), and X(YO)₂SiH (X = CH₃, C₂H₅/Y = CH₃, C₂H₅ … tert.-C₄H₉). The cause of this behavior is in all probability the existence of rotational isomers. Raman polarization measurements at organosubstituted silicon di- and trihydrides demonstrate the accidental degeneracy of the SiH valence vibrations.     

The spectra and structure of sulphur-containing organic compounds—V. The vibrational spectra and conformations of p-RC6H4SO2CH2X sulphones

The i.r. and Raman spectra of p-RC₆H₄SO₂CH₂X (R = H, CH₃, Cl, Br; X = Cl, Br) sulphone liquid solutions and crystals have been investigated. The existence of a mixture of trans and gauche conformations in liquid and solution phases has been established. The temperature dependences of the i.r. spectra have been studied and the values of ΔH = H (gauche) - H(trans) determined. The molecular conformations in the crystal have been determined by the dichroism of polarized i.r. spectral bands. In the case of CH₃C₆H₄SO₂CH₂Br polymorphic crystal modifications, differing in molecular conformations, have been found. An interpretation of the vibrational spectra is given. See Part IV, A. B. REMizov, F. S. BILALOV and 1. S. POMINOV, Spectrochim Acta, in press.     

Linear-free energy relationships in solid-state reactions: I. Reactions of cobalt acetate with substituted aniline hydrochlorides

Solid-solid reactions of anhydrous cobalt(II) acetate with various substituted aniline hydrochlorides have been studied. The reaction products, CoCl₂(4-XC₆H₄NH₂)₂, where X = OCH₃, CH₃, F, Br, or Cl, have been characterized. The kinetics have been studied by noting the thickness of the colored boundary of the product. The values of energy of activation are 162.3, 148.6, 120.4, 102.9, and 104.6 kJ mole⁻¹ for X = OCH₃, CH₃, F, Br, and Cl, respectively. A plot of Hammett's constant σ versus log k is linear with values of ϱ 2.321, 2.012, 1.781, and 1.615 at 353, 358, 363, and 368 K, respectively.     

Neue Synthesewege für Organohalogenstibane

New Methods for Synthesis of Organohalogenostibanes Organohalogenostibanes RSbX₂ (R = CH₃, C₆H₅; X = Cl, Br) and R₂SbX (R = C₆H₅; X = Cl) are received in good yields by alkylation or arylation of the corresponding antimony halides with Pb(CH₃)₄, Sn(CH₃)₄, Sb(CH₃)₃, or Sb(C₆H₅)₃. These methods are better than those, described in the literature for preparation of the compounds.     

β-Position Electronic Effects on the Singlet–Triplet Gaps of Divalent Five-Membered Rings XC4H3M (M˭C,Si, and Ge)

Abstract

Full geometry optimizations were carried out on the singlet and triplet states of β-substituted divalent five-membered rings XC₄H₃M (X? ?NH₂, ?OH, ?CH₃ ?H, ?CH₃, ?Br, ?Cl, ?F, ?CF₃, and ?NO₂; M?C, Si, and Ge) by the B3LYP method by using 6-311++G** basis set. The thermal energy gaps, ΔE_t–s; enthalpy gaps, ΔH_t–s; and Gibbs free energy gaps, ΔG_t–s, between the singlet (s) and triplet (t) states of the above structures were calculated by using the GAUSSIAN 03 program. The ΔG_t–s of XC₄H₃C was changed in the order: X? ?Cl > ?Br > ?CH₃ > ?H > ?CF₃ > ?F > ?NO₂ > ?OH > ?NH₂. The changes of ΔG_t–s for XC₄H₃Si and XC₄H₃Ge were in the order: X? ?NH₂ > OH > F > Cl > Br > CH₃ > H > CF₃ > NO₂. The geometrical parameters, including bond lengths (R), bond angles (A), dihedral angles (D), natural bonding orbital (NBO) charge at atoms, HOMO and LUMO, and dipole moments, were presented and discussed.

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GRAPHICAL ABSTRACT      

Force field studies of some trifluoromethyl- and trichloromethyl-mercury-II) compounds

Force constants of [Hg(CF₃)₂], [Hg(CCl₃)₂], [Hg(CF₃)X] (X = Cl, Br, or I) and [Hg(CCl₃)X] (X = Cl or Br) have been calculated using a valence force field and wavenumber data from solutions. The potential energy distributions show substantial mixing between the symmetrical stretching and umbrella deformation coordinates of the trihalomethyl groups. The high degree of mixing of HgC and HgX stretching coordinates in [Hg(CF₃)Br] and [Hg(CF₃)I] accounts for the discontinuous frequency and intensity trends in the [Hg(CF₃)X] series.The results are discussed in comparison with methylmercury and other trifluoromethyl systems.