A widely varying range of products in reactions of C6F5BrF2, C6F5IF2, and C6F5IF4 with Lewis acids of different strength

The relative fluoride donor ability: C₆F₅BrF₂ > C₆F₅IF₂ > C₆F₅IF₄ was outlined from reactions with Lewis acids of graduated strength in different solvents. Fluoride abstraction from C₆F₅HalF₂ with BF₃·NCCH₃ in acetonitrile (donor solvent) led to [C₆F₅HalF·(NCCH₃)_n][BF₄]. The attempted generation of [C₆F₅BrF]⁺ from C₆F₅BrF₂ and anhydrous HF or BF₃ in weakly coordinating SO₂ClF gave C₆F₅Br besides bromoperfluorocycloalkenes C₆BrF₇ and 1-BrC₆F₉. In reactions of C₆F₅IF₂ with SbF₅ in SO₂ClF the primary observed intermediate (¹⁹F NMR, below 0 °C) was the 4-iodo-1,1,2,3,5,6-hexafluorobenzenium cation, which converted into C₆F₅I and 1-IC₆F₉ at 20 °C. The reaction of C₆F₅IF₄ with SbF₅ in SO₂ClF below −20 °C gave the cation [C₆F₅IF₃]⁺ which decomposed at 20 °C to C₆F₅I, 1-iodoperfluorocyclohexene, and iodoperfluorocyclohexane. Principally, the related perfluoroalkyl compound C₆F₁₃IF₄ showed a different type of products in the fast reaction with AsF₅ in CCl₃F (−60 °C) which resulted in C₆F₁₄. Intermediate and final products of C₆F₅HalF_n−1 (n = 3, 5) with Lewis acids were characterized by NMR in solution. Stable solid products were isolated and analytically characterized.     

19F NMR analysis of the fluorides of perfluorocyclohexane-sulphonic acid and of 3-trifluoromethylperfluorocyclopentane-1-sulphonic acid

From the electrochemical fluorination of the chloride and the fluoride of benzenesulphonic acid, in addition to the main product C₆F₁₁SO₂F, the side products C₅F₈(CF₃)SO₂F, a structural isomer of the main product and C₆F₁₀Cl? SO₂F are also obtained. The NMR analysis of these products was performed. Chemical shift and coupling constant values were obtained for all the compounds. The NMR parameters of the main product are compared with those of perfluoromethylcyclohexane according to the data of Jolley, Sutcliffe and Walker. From the NMR parameters of C₅F₈(CF₃)SO₂F it was possible to demonstrate that substitution on the ring for —SO₂F and CF₃— is of the 1,3 and not the 1,2 type.     

Synthese d'acides perfluoroalcane carboxylique et sulfinique par reduction electrochimique d'iodures de perfluoroalkyle sur cathode en fibres de carbone dans le solvant N,N dimethylformamide. Application a la synthese de perfluoro α,ω diacides.

The electrochemical reduction of C₆F₁₃I on a carbon fibre cathode in DMF as solvent and in the presence of SO₂ is studied. Depending on the water content of the solvent, perfluorohexyl sulfinic acid C₆F₁₃SO₂H or perfluoropentyl carboxylic acid C₅F₁₁COOH are obtained. These reactions are applied to 1,4-diiodoperfluorobutane; by varying the composition of the solvent it has been possible to obtain the two diacidic compounds: HO₂S(CF₂)₄SO₂H and HO₂S(CF₂)₃COOH.     

Long‐Lived Radical Cation Salts Obtained by Interaction of Monocyclic Arenes with Niobium and Tantalum Pentahalides at Room Temperature: EPR and DFT Studies

The 1:3 reactions of the alkoxy arenes 1,4‐(MeO)₂C₆H₄ and 1,4‐F₂‐2,5‐(MeO)₂C₆H₂ with TaF₅ in chloroform at 40–50 °C resulted in formation in about 35 % yield of the long‐lived radical cation salts [1,4‐(MeO)₂C₆H₄][Ta₂F₁₁] ( 2 a ) and [1,4‐F₂‐2,5‐(MeO)₂C₆H₂][Ta₂F₁₁] ( 2 b ), respectively. The non‐alkoxy‐substituted [arene][M₂X₁₁] [M=Ta, X=F: arene=C₆H₅Me ( 2 c ), 1,4‐C₆H₄Me₂ ( 2 d ), C₆H₅F ( 2 e ), C₆H₅NO₂ ( 2 f ); M=Nb, X=F: arene=C₆H₅Me ( 4 a ), 1,4‐C₆H₄Me₂ ( 4 b ), C₆H₅F ( 4 c ), C₆H₅NO₂ ( 4 d ); M=Ta, X=Cl: arene=1,4‐C₆H₄Me₂ ( 5 )] were obtained from the 3:1 reactions of MX₅ with the appropriate arene in chloroform at temperatures in the range 40–90 °C. Compounds 2 – 5 were detected by EPR spectroscopy (in CHCl₃) at room temperature, and their gas‐phase structures were optimized by DFT calculations. Formation of the M^IV species [MX₄(NCMe)₂] [M=Ta, X=F ( 3 a ); M=Nb, X=F ( 3 b ); M=Ta, X=Cl ( 3 c )] was ascertained by EPR spectroscopy on solutions obtained by treatment of the reaction mixtures with acetonitrile. Non‐selective reactions occurred upon combination of 1,4‐F₂‐2,5‐(MeO)₂C₆H₂ with AgNbF₆ (in CH₂Cl₂) and 1,4‐(MeO)₂C₆H₄ with SbF₅.     

(Fluoroorgano)fluoroboranes and ‐borates. 7 [1] The Reaction of RFBF2 and K [RFBF3] (RF = perfluorophenyl‐, perfluoroalk‐1‐enyl‐ and perfluoroalkyl) with Xenon Difluoride in Anhydrous HF

The dissolution of (perfluoroorgano)difluoroboranes R_FBF₂ in anhydrous HF (aHF) resulted in equilibrium mixtures of the starting borane and different kinds of acid‐base products: [H₂F] [R_FBF₂(F · HF)] (R_F = C₆F₅, cis‐C₂F₅CF=CF, trans‐C₄F₉CF=CF) or [H₂F] [R_FBF₃] (R_F = C₆F₁₃). In aHF the aryl compounds C₆F₅BF₂ and K [C₆F₅BF₃] showed two parallel reactivities with XeF₂: xenodeborylation (formation of the [C₆F₅Xe]⁺ cation) and fluorine addition to the aryl group. In aHF perfluoroalk‐1‐enyldifluoroboranes R_FBF₂ as well as potassium perfluoroalk‐1‐enyltrifluoroborates K [R_FBF₃] (R_F = cis‐C₂F₅CF=CF, trans‐C₄F₉CF=CF) underwent only fluorine addition across the carbon‐carbon double bond under the action of XeF₂. Potassium perfluorohexyltrifluoroborate K [C₆F₁₃BF₃] did not react with XeF₂ in aHF.     

Aryl(pentafluorphenyl)iodoniumtetrafluoroborate: allgemeine Synthesemethode,typische Eigenschaften und strukturelle Gemeinsamkeiten

Pentafluorophenyliodine(III) Compounds. 4 [1] Aryl(pentafluorophenyl)iodoniumtetrafluoroborates: General Method of Synthesis, Typical Properties, and Structural Features Aryl(pentafluorophenyl)iodoniumtetrafluoroborates [Ar′Ar″I][BF₄] (Ar′ = C₆F₅, Ar″ = C₆H₅, o‐C₆H₄F, m‐C₆H₄F, p‐C₆H₄F, 2,6‐C₆H₃F₂, 3,5‐C₆H₃F₂, 2,4,6‐C₆H₂F₃, 3,4,5‐C₆H₂F₃, C₆F₅) are prepared in good yields and high purity by the reaction of C₆F₅IF₂ with Ar″BF₂ in CH₂Cl₂. This convenient method can be applied generally to many iodonium compounds. Thermal and spectroscopic properties (¹H, ¹³C, ¹⁹F NMR, IR, Raman) are reported and discussed. The solid state structures of six iodonium compounds show significant cation‐anion interactions which result in two different arrangements: a dimer with a 8‐membered ring or polymers with infinite zigzag chains. Ab initio calculations on prototypes of aryliodonium cations show relations between the kind of the aryl group (C₆H₅ vs. C₆F₅) and structural parameters as well as charges. By means of ¹⁹F NMR the σ_I‐ and σ_R‐constants of the [C₆F₅I]⁺‐substituent are determined.     

Halogen bonding in a series of Br(CF2)nBr–DABCO adducts (n = 4, 6, 8)

Halogen bonding (XB) is a highly‐directional class of intermolecular interactions that has been used as a powerful tool to drive the design of crystals in the solid phase. To date, the majority of XB donors have been iodine‐containing compounds, with many fewer involving brominated analogues. We report the formation of adducts in the vapour phase from a series of dibromoperfluoroalkyl compounds, BrCF₂(CF₂)_n CF₂Br (n = 2, 4, 6), and 1,4‐diazabicyclo[2.2.2]octane (DABCO). Single‐crystal X‐ray diffraction studies of the colourless crystals identified 1,4‐diazabicyclo[2.2.2]octane–1,4‐dibromoperfluorobutane (1/1), C₄Br₂F₈·C₆H₁₂N₂, (I), 1,4‐diazabicyclo[2.2.2]octane–1,6‐dibromoperfluorohexane (1/1), C₆Br₂F₁₂·C₆H₁₂N₂, (II), and 1,4‐diazabicyclo[2.2.2]octane–1,8‐dibromoperfluorooctane (1/1), C₈Br₂F₁₆·C₆H₁₂N₂, (III), each of which displays a one‐dimensional halogen‐bonded network. All three adducts exhibit N…Br distances less than the sum of the van der Waals radii, with butane analogue (I) showing the shortest N…Br halogen‐bond distances yet reported between a bromoperfluorocarbon and a nitrogen base [2.809 (3) and 2.818 (3) Å], which are 0.58 and 0.59 Å shorter than the sum of the van der Waals radii.     

Mono‐ and Perfluoroaryliodine(III) Cyano Compounds – Synthesis,Reactivity, and Structure

C₆F₅I(CN)₂ and x‐FC₆H₄I(CN)₂ (x = 2, 3, 4) were isolated from reactions of the corresponding aryliodine difluorides ArIF₂ and a stoichiometric excess of Me₃SiCN in CCl₃F (0 °C) or CH₂Cl₂ (20 °C), respectively. In addition, x‐FC₆H₄I(CN)₂ compounds were synthesized in good yields on alternative routes, namely from 3‐ or 4‐FC₆H₄I(OC(O)CH₃)₂ or 4‐FC₆H₄I(OC(O)CF₃)₂ or from 4‐FC₆H₄IO and Me₃SiCN in CH₂Cl₂ at 20 °C. In the 1 : 1 reaction of C₆F₅IF₂ and Me₃SiCN a lower temperature was necessary to suppress partial disubstitution and to obtain the first example of a new type of aryliodine(III) cyanide compounds, C₆F₅I(CN)F. 4‐FC₆H₄I(CN)F could be isolated from the equimolar reaction of 4‐FC₆H₄IF₂ and Me₃SiCN in CH₂Cl₂ even at 20 °C. The new products were characterized by multi‐NMR and Raman spectroscopy. The molecular structures of C₆F₅I(CN)₂, 3‐ and 4‐FC₆H₄I(CN)₂, C₆F₅I(CN)F, and 4‐FC₆H₄I(CN)F are discussed and compared with that of C₆F₅IF₂. The reactivity of C₆F₅I(CN)F towards fluoride acceptors EF_n (BF₃, AsF₅) and R_xEX_?x (C₆F₅SiF₃, C₆H₅SiF₃, C₆H₅PF₄, Me₃SiCl, Me₃SiC₆F₅) were investigated and showed differing reaction patterns (fluoride abstraction, aryl transfer, chloride transfer). Besides the molecular entities C₆F₅I(CN)F and C₆F₅I(CN)Cl, the corresponding iodonium salts [C₆F₅(CN)I][BF₄] and [C₆F₅(CN)I][AsF₆] were isolated. The thermal stability of ArI(CN)₂ and ArI(CN)F, neat and in solution, as well as the reactivity of 4‐FC₆H₄I(CN)₂ towards the Lewis acid BF₃ are reported.     

Strukturen von neuen Bis(pentafluorophenyl)halogenomercuraten [{Hg(C6F5)2}3(μ‐X)]— (X = Cl,Br, I)

Structures of New Bis(pentafluorophenyl)halogeno Mercurates [{Hg(C₆F₅)₂}₃(μ‐X)]^— (X = Cl, Br, I) From the reactions of [PNP]Cl or [PPh₄]Y (Y = Br, I) with Hg(C₆F₅)₂ crystals of the composition [Cat][{Hg(C₆F₅)₂}₃X] (Cat = PNP, X = Cl ( 1 ); Cat = PPh₄, X = Br ( 2 ), I ( 3 )) are formed. 1 crystallizes in the triclinic space group P1¯, 2 and 3 crystallize isotypically in the monoclinic space group C2/c. In the crystals the halide anions are surrounded by three Hg(C₆F₅)₂ molecules. The reaction of [PPh₄]Br with Hg(C₆F₅)₂ under slightly changed conditions gives the compound [PPh₄]₂[{Hg(C₆F₅)₂}₃(μ‐Br)][{Hg(C₆F₅)₂}₂(μ‐Br)] ( 4 ).     

ZUR DARSTELLUNG VON BENZODITHIET-DERIVATEN DURCH THERMOLYSE 1,2-DITHIO-SUBSTITUIERTER BENZOLE

Abstract

The thermal fragmentation of various 1,2-dithio-benzene derivatives R₄C₆S₂(X) with R = H, CH₃, F in order to split off favorable leaving molecules × = Cl₂, CO or H₂C[dbnd]CH₂ and to generate the corresponding benzene-1,2-dithiete products (R₄C₆S₂), is investigated in a gas-flow reactor using real-time PE spectroscopic analysis. Results observed are: 1,2-bis(chloromercapto) benzene H₄C₆(SCl)₂ yields 1,2-benzodithiete H₄C₆S₂; none of the tetramethylated precursors fragments to the elusive tetramethyl derivative (H₃C)₄C₆S₂, but decarbonylation of tetrafluoro 1,2-benzodithio-2-on F₄C₆S₂(CO) leads to rather reactive tetrafluoro 1,2-benzodithiete F₄C₆S₂. Characteristic ionisation patterns are assigned by radical cation state comparison and by Koopmans' correlations based on MNDO eigenvalues.

Die thermische Fragmentierung verschiedenartiger 1,2-Dithiobenzol-Derivative R₄C₆S₂(X) mit R = H, CH₃, F, die unter Abspaltung günstiger Abgangsmoleküle × = Cl₂, CO oder H₂C[dbnd]CH₂ die entsprechenden Benzo-1,2-dithiet-Produkte (R₄C₆S₂) liefern konnte, wird in einem Gasdurchfluβ-Reaktor mit PE-spektroskopischer Echtzeit-Analytik untersucht. Beobachtet wird: 1,2-Bis(chloro-mercapto)benzol H₄C₆(SCl)₂ liefert 1,2-Benzodithiet; keine der tetramethylierten Ausgangsverbin-dungen fragmentiert zum vermutlich instabilen Tetramethyl-Derivat (H₃C)₄C₆S₂, aber Decar-bonylierung von Tetrafluor-1,2-benzodithio-2-co F₄C₆S₂(CO) führt zum reaktiven Tetrafluor-1,2-benzodithiet. Die charakteristischen lonisienmgsmuster werden durch Radikalkationenzustands-Vergleiche sowie durch Koopmans'-Korrelation mit MNDO-Eigenwerten zugeordnet.     

Intermolecular C—H...O and C—H...X interactions in substituted spiroacenaphthylene structures

In the three spiroacenaphthylene structures 5′′‐[(E)‐2,3‐dichlorobenzylidene]‐7′‐(2,3‐dichlorophenyl)‐1′′‐methyldispiro[acenaphthylene‐1,5′‐pyrrolo[1,2‐c][1,3]thiazole‐6′,3′′‐piperidine]‐2,4′′‐dione, C₃₅H₂₆Cl₄N₂O₂S, (I), 5′′‐[(E)‐4‐fluorobenzylidene]‐7′‐(4‐fluorophenyl)‐1′′‐methyldispiro[acenaphthylene‐1,5′‐pyrrolo[1,2‐c][1,3]thiazole‐6′,3′′‐piperidine]‐2,4′′‐dione, C₃₅H₂₈F₂N₂O₂S, (II), and 5′′‐[(E)‐4‐bromobenzylidene]‐7′‐(4‐bromophenyl)‐1′′‐methyldispiro[acenaphthylene‐1,5′‐pyrrolo[1,2‐c][1,3]thiazole‐6′,3′′‐piperidine]‐2,4′′‐dione, C₃₅H₂₈Br₂N₂O₂S, (III), the substituted aryl groups are 2,3‐dichloro‐, 4‐fluoro‐ and 4‐bromophenyl, respectively. The six‐membered piperidine ring in all three structures adopts a half‐chair conformation, the thiazolidine ring adopts a slightly twisted envelope and the pyrrolidine ring an envelope conformation; in each case, the C atom linking the rings is the flap atom. In all three structures, weak intramolecular C—H...O interactions are present. The crystal packing is stabilized through a number of intermolecular C—H...O and C—H...X interactions, where X = Cl in (I) and F or S in (II), and C—H...O interactions are observed predominantly in (III). In all three structures, molecules are linked through centrosymmetric ring motifs, further tailored through a relay of C—H...X [Cl in (I), Br in (II) and O in (III)] interactions.     

Investigation of heterocycles containing nitrogen or sulfur. 48. Derivatives of 1-morpholinooxalyl-1,2-dihydrothiazolo-[5,4-b]pyridine,their structure,and reactions

The structures of the products of reactions of 1-N-morpholinooxahi-1,2-dihydrothiazolo-[5,4-b]pyridine have been studied by IR, NMR, UV, and mass spectroscopy. Geometric (cis-anti) and rotational (about the CO-N amide bond) isomers of 1-N-morpholinooxalyl-2-propionyi-5-chloro-1,2-dihydrothiazolo-[5,4-b]pyridine oxime have been observed and studied. Treatment of 1-N-morpholinooxalyl-2-propionyl-5-chloro-1,2-dihydrothiazolo[5,4-b]pyridine with ethanolic alkali gave 2-propionyl-5-chlorothiazolo-[5,4-b]pyridine, while treatment with concentrated H₂SO₄ gave 1,2-dioxo-ethylidene-7-chloroxazolidino[3,2-f]pyrido[2,3-b]1,4-thiazine.For Communication 47 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1133–1138, August, 1993.     

Three closely related thienyl‐substituted 1,4‐epoxynaphtho[1,2‐b]azepines: hydrogen‐bonded assembly in one,two and three dimensions

(2R,4S)‐2‐(3‐Methylthiophen‐2‐yl)‐2,3,4,5‐tetrahydro‐1,4‐epoxynaphtho[1,2‐b]azepine, C₁₉H₁₇NOS, (I), crystallizes with a single enantiomer in each crystal, whereas its geometrical isomer (2RS,4SR)‐2‐(5‐methylthiophen‐2‐yl)‐2,3,4,5‐tetrahydro‐1,4‐epoxy‐naphtho[1,2‐b]azepine, (II), and (2RS,4SR)‐2‐(5‐bromothiophen‐2‐yl)‐2,3,4,5‐tetrahydro‐1,4‐epoxynaphtho[1,2‐b]azepine, C₁₈H₁₄BrNOS, (III), both crystallize as racemic mixtures. A combination of one C—H...O hydrogen bond and two C—H...π(arene) hydrogen bonds links the molecules of (I) into a three‐dimensional framework; the molecules of (II) are linked into a C(4)C(4)[R₂²(7)] chain of rings by a combination of C—H...N and C—H...O hydrogen bonds; and in (III), where Z′ = 2, a combination of four C—H...π(arene) hydrogen bonds and two C—H...π(thienyl) hydrogen bonds links the molecules into complex sheets. Comparisons are made with the assembly patterns in some aryl‐substituted 1,4‐epoxynaphtho[1,2‐b]azepines.     

Reactions of Alk‐1‐enylxenonium(II) and Alk‐1‐ynylxenonium(II) Salts [RXe]Y with Bromides and Iodides in Anhydrous HF

The replacement of xenon(+) by iodine in reactions of alkenylxenonium(II) salts [RCF=CFXe]Y (R = cis-C₂F₅, trans-H) and alkynylxenonium(II) salt [C₃F₇C≡CXe][BF₄] with NaI in anhydrous HF (aHF) occurred regiospecifically. At −60 °C the substitution of xenon(+) by bromine in the perfluorinated salts [cis-CF₃CF=CFXe]Y and [trans-C₄F₉CF=CFXe]Y proceeded regio- and stereospecifically with NaBr in aHF, but at a higher temperature and after a longer time the treatment of [cis-C₂F₅CF=CFXe]Y with NaBr, KBr, or [NBu₄]Br in aHF gave mixtures of cisand trans-perfluorobut-1-enyl bromides. The reaction of [C₃F₇C≡CXe][BF₄] with NaBr in aHF at −65 °C gave only 48 %, of C₃F₇C≡CBr and was accompanied by a mixture of bromine-containing related olefins. Reaction pathways to the main product are discussed.     

Synthesis of 1H-naphth[2,3-d]imidazole-4,9-diones by acid catalyzed cyclization of 2-Acylamino-3-amino-1,4-naphthoquinones

The conversion of 2-acylamino-3-amino-1,4-naphthoquinones (II) to the corresponding 2-substituted 1H-naphth[2,3-d]imidazole-4,9-diones (I) under both alkaline and acid catalyzed conditions has been effected and the results compared. Treatment of 3-(4′-chlorobutanonyl-amino)-3-amino-1,4-naphthoquinone (He) with aqueous ethanolic sodium hydroxide solution gives 1,2-butanonaphth[2,3-d]imidazole-4,9-dione (V); whereas, treatment of lie with refluxing formic acid gave 2-(4′-chlorobutyl)-1H-naphth[2,3-d]imidazole-4,9-dione. Treatment of 2-substi-tuted 1H-naphth[2,3-d]imidazole-4,5-diones in DMF with alkyl halides in the presence of potassium carbonate affords the expected 1,2-disubstituted naphth[2,3-d]imidazole-4,9-diones (VI). The spectral properties of I, II, V and VI as well as those of some 2-acylamino-3-chloro-1,4-naphthoquinones IV are discussed.     

Pentafluorophenyl derivatives of chlorine trifluoride

A reaction between C₆F₅Cl and elemental fluorine under pressure produced pentafluorophenylchlorine(III)difluoride⁽¹⁾ and 1,2-difluoro-1,2-bis(pentafluorophenyl)dichlorane, C₆F₅Cl(F)Cl(F)C₆F₅.The dichlorane was a stable colorless liquid with a boiling point of 121 – 123°. Its characterization by elemental analysis, IR, NMR and Mass Spectra will be presented. It is believed to be the first stable compound with a chlorine-chlorine bond and may be considered to be a derivative of the unknown Cl₂F₄.     

Selective synthesis of bis[1,2]dithiolo[1,4]thiazines from 4-isopropylamino-5-chloro-1,2-dithiole-3-ones

Reaction of 4-isopropylamino-5-chloro-1,2-dithiole-3-ones 3 and S₂Cl₂ in acetonitrile gave selectively 3-oxo-bis[1,2]dithiolo[1,4]thiazine-5-thiones 1 by the addition of triethylamine and bis[1,2]dithiolo[1,4]thiazine-3,5-diones 5 under the action of formic acid. 3,5-Diones 5 were also obtained by intramolecular cyclization of N,N-bis(5-chloro-3-oxo[1,2]dithiol-4-yl)amines 6 with S₂Cl₂ in the presence of Et₃N.     

19F nmr spectra of mesomeric carbanions generated from polyfluorodiarylacetonitriles. The electronic effect of perfluoroalkyl groups

¹⁹F NMR spectra of 1,2- dimethoxyethane solutions of Na- and Li- salts of polyfluorinated carbanions [p - RC₆F₄$\text{C}$(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.     

Geminal Dicationic Ionothermal Synthesis of One Three-Dimensional Luminescent Strontium(II) Coordination Polymer Based on 1,4-Naphthalenedicarboxylate Acid

One three-dimensional Sr(II) coordination polymer [C₆(MIm)₂][Sr₃(1,4-NDC)₄] (I) (C₆(MIm)₂ = 1,3-bis(3-methylimidazolium-1-yl)hexyl, 1,4-H₂NDC = 1,4-naphthalenedicarboxylate acid) has been synthesized using an ionothermal method and structurally characterized by IR spectroscopy, UV-Vis spectroscopy, XRPD, and X-ray single-crystal structure analysis (СIF file CCDC 1033958). Two types of strontium centers are bridged by two coordination modes of 1,4-H₂NDC ligands to form a Sr(II) chain. Each Sr(II) chain is crossconnected to four other chains to generate a 3D coordination polymer, in which C₆(MIm) ₂ ²⁺ cations as charge balancing species are filled in the channels of the anionic framework. The polymeric solid of I exhibits strong luminescent emission at room temperature.     

New types of asymmetrical bromonium salts [RF(RF′)Br]Y where RF and/or RF′ represent perfluorinated aryl, alkenyl, and alkynyl groups

A series of previously unknown asymmetrical fluorinated bis(aryl)bromonium, alkenyl(aryl)bromonium, and alkynyl(aryl)bromonium salts was prepared by reactions of C₆F₅BrF₂ or 4-CF₃C₆H₄BrF₂ with aryl group transfer reagents Ar′SiF₃ (Ar′ = C₆F₅, 4-FC₆H₄, C₆H₅) or perfluoroorganyl group transfer reagents R_F′BF₂ (R_F = C₆F₅, trans-CF₃CFCF, C₃F₇C≡C) preferentially in weakly coordinating solvents (CCl₃F, CCl₂FCClF₂, CH₂Cl₂, CF₃CH₂CHF₂ (PFP), CF₃CH₂CF₂CH₃ (PFB)). The presence of the base MeCN and the influence of the adducts R_F′BF₂·NCMe (R_F = C₆F₅, CF₃C≡C) on reactions aside to bromonium salt formation are discussed. Reactions of C₆F₅BrF₂ with Alk_F′BF₂ in PFP gave mainly C₆F₅Br and Alk_F′F (Alk_F′ = C₆F₁₃, C₆F₁₃CH₂CH₂), presumably, deriving from the unstable salts [C₆F₅(Alk_F′)Br]Y (Y = [Alk_F′BF₃]⁻). Prototypical reactivities of selected bromonium salts were investigated with the nucleophile I^-and the electrophile H⁺. [4-CF₃C₆H₄(C₆F₅)Br][BF₄] showed the conversion into 4-CF₃C₆H₄Br and C₆F₅I when reacted with [Bu₄N]I in MeCN. Perfluoroalkynylbromonium salts [C_nF_2n+1C≡C(R_F)Br][BF₄] slowly added HF when dissolved in aHF and formed [Z-C_nF_2n+1CFCH(R_F)Br][BF₄].