Dieter Naumann

A new synthesis of trifluoromethanethiolates—characterization and properties of tetramethylammonium, cesium and di(benzo-15-crown-5)cesium trifluoromethanethiolates

Abstract [NMe4]SCF3, CsSCF3 and [(B-15-C-5)2Cs]SCF3 (B-15-C-5: benzo-15-crown-5) are formed from reactions of the corresponding fluorides, trimethyl(trifluoromethyl)silane, Me3SiCF3, and elemental sulfur in glyme or THF. All compounds are colorless to pale ochre solids decomposing significantly above ambient temperature. Excellent agreement between experimental and theoretical vibrational frequencies, calculated at the B3PW91 level of theory, impressively confirms the salt-like nature of [NMe4]SCF3. The properties of the title compounds as nucleophilic SCF3 transfer reagents were checked with a variety of organic, organometallic and inorganic compounds.

Darstellung, NMR-spektroskopische Charakterisierung und reaktionen von perfluoralkylsilber(I)-verbindungen☆

Abstract Perfluoroalkylsilver(I) compounds are obtained via ligand exchange reactions of AgNO 3 and Cd(R f ) 2 compounds in aprotic polar solvents. Equilibria between the neutral species AgR f · D and the ionic species [Ag(R f ) 2 ] − involve silver(1) ions and exhibit strange solvent-dependency. The 19 F- and 109 Ag-NMR data as well as the T t -values have been measured. Reactions with e.g. C 6 H 5 HgCl proceed at −30°C within a few minutes to give the corresponding phenyl(perfluoroalkyl)mercury derivatives. However, the versatility of AgR f reagents as perfluoroalkyl-group transfer reagents in DMF and N(C 2 H 5 ) 3 remains limited.

Syntheses and Properties of Tetrakis(pentafluorophenyl)tellurium, Te(C6F5)4, and Related Compounds — Single Crystal Structures of Tris(pentafluorophenyl)tellurium Bromide, Te(C6F5)3Br, Tris(pentafluorophenyl)tellurium Trifluoromethanesulfonate, [Te(C6F5)3][OSO2CF3], and Bis(pentafluorophenyl)tellurium Oxide, Te(C6F5)2O

Te(C6F5)4 was prepared from the reactions of TeCl4 or Te(C6F5)2Cl2 with Grignard reagents or AgC6F5 in moderate to good yields. Substitution reactions with Me3SiX (X = Cl, Br, OSO2CF3), with equimolar amounts of Br2, with AgNO3 and with H[BF4] or BF3·OEt2 yielded the Te(C6F5)3X derivatives (X = Cl, Br, OSO2CF3, NO3, BF4). Oxidation reactions of Cd, Hg, and Pd0 complexes led to Te(C6F5)2 and the corresponding bis(pentafluorophenyl) derivatives M(C6F5)2 (M = Cd, Hg, Pd) and with InBr to In(C6F5)2Br. From very slow hydrolysis of Te(C6F5)4 the oxide Te(C6F5)2O was prepared. The thermal decomposition, the NMR and mass spectra of the partially new compounds are discussed. The crystal structures of Te(C6F5)3Br (monoclinic, P21/a, Z = 4), [Te(C6F5)3][OSO2CF3] (monoclinic, P21/n, Z = 16) and [Te(C6F5)2O]2 (triclinic, P1¯, Z = 2) were determined. Die Synthesen und Eigenschaften von Tetrakis(pentafluorphenyl)tellur, Te(C6F5)4, und verwandten Verbindungen — Rontgenstrukturanalysen von Tris(pentafluorphenyl)-tellurbromid, Te(C6F5)3Br, Tris(pentafluorphenyl)tellurtrifluormethansulfonat, [Te(C6F5)3][OSO2CF3] und Bis(pentafluorphenyl)telluroxid, Te(C6F5)2O Te(C6F5)4 wurde durch die Umsetzungen von TeCl4 bzw. Te(C6F5)2Cl2 mit Grignardreagenzien oder AgC6F5 in masigen bis guten Ausbeuten dargestellt. Durch Substitutionsreaktionen mit Me3SiX (X = Cl, Br, OSO2CF3), mit aquimolaren Mengen Br2, mit AgNO3 sowie mit H[BF4] bzw. BF3·OEt2 entstanden die Te(C6F5)3X-Verbindungen (X = Cl, Br, OSO2CF3, NO3, BF4). Oxidationsreaktionen von Cd-, Hg- und Pd0-Komplexen ergaben Te(C6F5)2 und die entsprechenden Derivate M(C6F5)2 (M = Cd, Hg, Pd); InBr wurde zu In(C6F5)2Br oxidiert. Durch sehr langsame Hydrolyse von Te(C6F5)4 wurde Te(C6F5)2O dargestellt. Die thermischen Zersetzungen sowie die NMR- und Massenspektren der teilweise neuen Verbindungen werden diskutiert. Die Kristallstrukturen von Te(C6F5)3Br (monoklin, P21/a, Z = 4), [Te(C6F5)3][OSO2CF3] (monoklin, P21/n, Z = 16) und [Te(C6F5)2O]2 (triklin, P1¯, Z = 2) wurden bestimmt.

Polar trifluoromethylation reations: syntheses of trifluoromethyl gallium, indium, and thallium compounds. The mechanism of polar trifluoromethyl group transfer

Abstract The reactions of Cd(CF 3 ) 2 complexes with GaCl 3 , InCl 3 , and TlX 3 (X: Cl, OCOCH 3 , OCOCF 3 ) in aprotic basic solvents have given the compounds Ga(CF 3 ) 3 ·dmf, Ga(CF 3 ) 2 Cl·dmf, [Cd(CH 3 CN) 2 ]-[Ga(CF 3 ) 4 ] 2 , In(CF 3 ) 3 ·2CH 3 CN, In(CF 3 ) 2 Cl·dmf, and Tl(CF 3 ) 3 ·2dmf, which have been characterized by NMR spectroscopy, mass spectrometry, vibrational spectroscopy, and elemental analysis. All trifluoromethylmetal halides formed as intermediates were detedted by 19 F NMR spectroscopy. The dependence of the chemical shifts and the coupling constants 2 J ) 203/205 Tl 19 F) on the number of CF 3 -groups bound to the central atom provides unambiguous evidence for the formular of trifluoromethyl gallates and thallates and the existence of the [Ga(CF 3 ) 4 − -anion has been confirmed by 71 Ga NMR spectroscopy. A mechanism for successful polar trifluoromethyl group transfer is discussed on the basis of Pearsons HSAB concept and the results of conductivity measurements.

Trifluoromethylmetallate anions as components of molecular charge transfer salts and superconductors

Abstract Whereas polymeric and common inorganic anions frequently deprive the synthetic chemist of a chance to modify a charge transfer salt’s structure through anion alterations, discrete organometallic anions provide a vast opportunity to probe the structure/property correlations of a material through rational synthetic methods. We have recently undertaken a research effort aimed at the crystallization of conducting charge transfer salts which possess modifiable, organometallic anions as the charge compensating entities. This research has been richly rewarded with the discovery of a new family of bis(ethylenedithio)tetrathiafulvalene (BEDT–TTF or ET) based molecular superconductors. Herein is presented a summary of over 20 κ(ET) 2 M(CF 3 ) 4 (1,1,2-trihaloethane) (M=Cu, Ag, Au) superconducting salts. Three new related salts are also reported: (ET) 2 [ trans- Ag(CF 3 ) 2 (CN) 2 ], κ L (BEDT-TSF) 2 Ag(CF 3 ) 4 (TCE), and κ L (ET) 2 Ag(CF 3 ) 3 Cl(TCE).

The first organic cation-radical salt superconductor (Tc= 4 K) with an organometallic anion: superconductivity, synthesis and structure of κL-(BEDT-TTF)2Cu(CF3)4·TCE

Superconductivity at ambient pressure with onset Tc= 4.00 ± 0.05 K is reported in a unique organic cation-radical salt κL-(ET)2Cu(CF3)4·TCE, [ET = bis(ethylenedithio)tetrathiafulvalene, TCE = 1,1,2-trichloroethane] with the Cu(CF3)4– species being the first Cu3+ and F containing organometallic anion in an organic superconductor.

Cyanide initiated perfluoroorganylations with perfluoroorgano silicon compounds

Abstract Cyanophenylphosphanes, Ph2PCN or PhP(CN)2, do not react with Me3SiCF3 or Me3SiC6F5 in the absence of cyanide ions. Catalytic amounts of ionic cyanides such as [NEt4]CN, [18-crown-6-K]CN or NaCN initiate perfluoroorganylation reactions. The trifluoromethylphosphines, Ph2PCF3 and PhP(CF3)2, as well as the pentafluorophenylphosphines, Ph2PC6F5 and PhP(C6F5)2, are isolated in 60–75% yield. In dimethylformamide or acetone solutions, side reactions are observed while reactions in CH2Cl2 and acetonitrile proceed selectively. Me3SiCF3 addition to the carbonyl groups of dimethylformamide and acetone occurs on treatment of Me3SiCF3 solutions of these solvents with catalytic amounts of cyanide, cyanate or thiocyanate salts even at low temperature. The formation of the reactive silicate [Me3Si(CN)CF3]− in reactions with an excess of [18-crown-6-K]CN is proved by low temperature NMR investigations.

Synthesen und Eigenschaften von Pentafluorethylkupfer(I)‐ und ‐(III)‐Verbindungen: Cu(C2F5) · D, [Cu(C2F5)2]– und (C2F5)2CuSC(S)N(C2H5)2

Cd(C2F5)2 · D bzw. Zn(C2F5)2 · D (D = 2 CH3CN, 2 DMF) reagieren mit Kupfer(I)halogeniden in Gegenwart von Halogeniden quantitativ zu den CuC2F5-Verbindungen CuC2F5 · D und [Cu(C2F5)2]–. Die CuC2F5-Komplexe werden NMR-spektroskopisch identifiziert, [Cu(C2F5)2]– wird als PNP-Salz (PNP = (C6H5)3PNP(C6H5)3+) isoliert. Beide Pentafluorethylkupfer(I)-Verbindungen sind bei tiefer Temperatur sehr reaktive Pentafluorethylierungs-Reagenzien. Die Oxidation von [Cu(C2F5)2]– mit [(C2H5)2NC(S)S]2 ergibt die kristalline Cu(III)-Verbindung (C2F5)2CuSC(S)N(C2H5)2 (monoklin, C2/c). Syntheses and Properties of Pentafluoroethylcopper(I) and -copper(III) Compounds: CuC2F5 · D, [Cu(C2F5)2]–, and (C2F5)2CuSC(S)N(C2H5)2 The reactions of Cd(C2F5)2 · D and Zn(C2F5)2 · D (D = 2 CH3CN, 2 DMF), respectively, with copper(I) halides in the presence of halides quantitatively yield the CuC2F5 compounds CuC2F5 · D and [Cu(C2F5)2]–. The CuC2F5 complexes are identified by NMR spectroscopy, while [Cu(C2F5)2]– is isolated as PNP salt (PNP = (C6H5)3PNP(C6H5)3+). Both compounds are excellent C2F5 group transfer reagents, even at low temperature. Oxidation of [Cu(C2F5)2]– with [(C2H5)2NC(S)S]2 yields the crystalline Cu(III) compound (C2F5)2CuSC(S)N(C2H5)2 (monoclinic, C2/c).

Bi(CF3)3/Cu(OCOCH3)2 — a new system for the synthesis of 2-trifluoromethylcycloalkan-1-ones, trifluoromethylanilines and phenyl(trifluoromethyl)sulfane

Abstract Bi(CF 3 ) 3 reacts in the presence of equimolar amounts of Cu(OCOCH 3 ) 2 and 1-morpholinocyclopentene to give 1-morpholino-2-trifluoromethylcyclopentene in 83% yield. This compound as well as intermediately formed 1-morpholino-2-trifluoromethylcyclohexene can easily be converted into the corresponding cycloketones (78 and 41% yield) using the Swarts procedure. In absence of a copper(II) source, no reactions were observed. The reaction of the system Bi(CF 3 ) 3 /Cu(OCOCH 3 ) 2 with N , N -diethylaniline gave an 1.7: 1 isomer mixture of 2-trifluoromethyl and 4-trifluormethyl- N , N -diethylanilines in 48% yield. With tetrabutylammonium thiophenolate, mixtures of phenyl(trifluoromethyl)sulfane and diphenyldisulfane were obtained. Mechanisms are discussed.

SYNTHESEN UND EIGENSCHAFTEN VON BIS(PERFLUORALKYL)ZINK-VERBINDUNGEN

Es werden die Reaktionsbedingungen fur die Synthesen von Bis(perfluoralkyl)zink-Verbindungen Zn(Rf)2 · 2 D (Rf = C2F5, n-C3F7, i-C3F7, n-C4F9, n-C6F13, n-C7F15 und n-C8F17; D = CH3CN, Tetrahydrofuran, Dimethylsulfoxid) beschrieben. Massenspektren, thermische Zersetzungen, 19F- und 13C-NMR-Spektren werden diskutiert. Syntheses and Properties of Bis(perfluoroalkyl)zinc Compounds The conditions for the syntheses of bis(perfluoroalkyl)zinc compounds Zn(Rf)2 · 2 D (Rf = C2F5, n-C3F7, i-C3F7, n-C4F9, n-C6F13, n-C7F15, and n-C8F17; D = CH3CN, tetrahydrofurane, dimethylsulfoxide) are described. Mass spectra, thermal decompositions, 19F- and 13C-NMR spectra are discussed.