Pyridine and benzonitrile adducts of bis(4-nonafluorobiphenyl)zinc

Treatment of (Ar_F′)₂Zn(OEt₂)₂ (Ar_F′ = 4-C₆F₅C₆F₄) with 2 equiv. of benzonitrile, 4-(phenyl)benzonitrile, 4-(pyrrolyl)benzonitrile, pyridine, 4-(phenyl)pyridine or 4-(pyrrolyl)pyridine in dichloromethane afforded the corresponding adducts (Ar_F′)₂ZnL₂ in near quantitative yield. The 2,2′-bipyridine adduct was prepared similarly. Multinuclear NMR spectroscopy indicated that zinc′s four-coordinate character was maintained in solution. The pyridine complex crystallized from dichloromethane with a solid-state structure free of face-to-face aryl–aryl interactions. In contrast, the 4-(pyrrolyl)pyridine adduct crystallized from both dichloromethane and 1,2-difluorobenzene, with solvent of crystallization, but otherwise essentially identical supramolecular architectures assembled through aryl–aryl synthons, including a face-to-face pentafluorophenyl–pyrrole interaction.     

Reaktionskinetik einer Monomolekularen Oberflächenbelegung von Germanium mit 4-(Trichlorsilylmethyl)benzonitril mit Hilfe von FTIR-Experimenten

Kinetics of Monomolecular Surface Modification of 4-(Trichlorosilylmethyl)benzonitrile on Germanium by Means of FTIR Experiments A Fourier transform-attenuated total internal reflection-infrared spectroscopy (FT-ATR-IR) technique is described, which allows to observe the kinetics of monomolecular surface modification on materials which are feasible to total internal reflection experiments in an appropriate wavelength region. First results are reported for the reaction of 4-(trichlorosilymethyl)benzonitrile on germanium. The reaction is slower than expected and is only completed after approximately 4 h.     

Die Bildung von Tetrαchlorocobaltat in Abhängigkeit vom Lösungsmittel

Formation of Tetrachloro Cobaltate in Dependence of the Solvent The individual complex formation constants and thermodynamic data for the reaction have been determined spectrophotometrically at different temperatures and ionic strengths in the following solvents (L): nitromethane, benzonitrile, acetonitrile, acetone, dimethylformamide, and dimethylacetamide. For solutions of tetrabutylammonium salts activities have been calculated up to total electrolyte concentrations of ≈? 10^?1 mol/liter. The molar absorptivities for both the tri- and the tetrachlorocomplex depend on the solvent; the free enthalpies are related to the solvent donicities.     

Fragmentierung von α-Aminoketoximen. V. Teil. (2-Chinuclidinyl)-phenyl-ketoxim. Zur Gültigkeit der BREDTschen Regel bei energiereichen Zwischenstufen Fragmentierungsreaktionen, 18. Mitteilung

The reaction of (2-quinuclidinyl) phenyl ketoxime tosylate ( 1 ) in aqueous ethanol or tetrahydrofuran yields 10 to 20% of benzonitrile and 4-piperidyl-acetaldehyde ( 6 ), the tautomer of 2-quinuclidinol ( 5 ), besides N-(2-quinuclidinyl)-benzamide ( 4 ). In phenol some 2-phenoxyquinuclidin ( 21 ) and benzonitrile are obtained besides phenyl N-(2-quinuclidinyl)-benzimidate ( 20 ). Furthermore, the α-aminoketoximetosylate 1 reacts 2 to 4 times as fast as the homomorphous (bicyclo[2.2.2]-2-octyl) phenyl ketoxime tosylate ( 7 ). By contrast the latter untergoes quantitative Beckmann rearrangement to the amide 12 .     

Synthese und Kristallstruktur von [WNCl3 · NC–Ph]4 · 3 CH2Cl2

Synthesis and Crystal Structure of [WNCl₃ · NCPh]₄ · 3 CH₂Cl₂ The adduct of tungsten nitride trichloride with benzonitrile, [WNCl₃ · NCPh]₄, is formed by the reaction of N,N,N'-tris(trimethylsilyl)benzamidine and tungsten hexachloride in CCl₄ solution. It forms red crystal needles and was characterized by its IR spectrum and an X-ray crystal structure determination (1983 unique observed reflexions, R = 0.075). Crystal data: a = 1464.8, b = 1902.6, c = 2033.8 pm, β = 102.27°, space group C2/c, Z = 4. In the [WNCl₃ · NCPh]₄ molecule the tungsten atoms were located at the vertices of a square and are linked with one another via linear W?N? W nitrido bridges with alternating short and long bonds having average lengths of 166 and 211 pm. The N atoms of the benzonitrile ligands are in the positions trans to the W?N bonds at distances of 237 pm.     

Über Ligandenumverteilungsreaktionen an ternären Siliciumtetrahalogeniden in Gegenwart von Pyridin

On Ligand-Rearrangement-Reactions at Mixed Silicon Tetrahalides in the Presence of Pyridine The exchange of substituents on mixed silicon tetrahalides completely takes place after few hours in CHCl₃ at 334 K in presence of small quantities of pyridine or pyridinium salts. The exchange equilibria does not deviate much from the values expected from ideal random sorting. Mixed silicon tetrahalides are stable for some days at 298 K in CHCl₃ in presence of pyridine or pyridinium salts respectively, so that by the reaction of binary silicon tetrahalides (SiBr₄, SiI₄) with (pyH)Cl all mixed silicon tetrahalides may be identified side by side. A separation by destillation of the mixtures is impossible because of easy dismutation reactions in presence of pyridine. The influence of pyridine takes place presumable above the formation of addition compounds.     

全氟和多氟烷基磺酸的研究 VIII: N-(3'-三氯硅基丙基)-3-氧杂全氟烷基磺酰胺及基衍生物的合成

3-OXaperfluoroalkanesulfonyl fluoride (1) reacted with allylamine to give the corresponding N-allylsulfonamide 2 which on treatment with sodium methoxide and methyl iodide affrded N-methyl-N-allyl-3 -oxaperfluoroalkanesulfonamide 3. 2 and 3 were converted to the corresponding substituted trichlorosilanes 4 and 5 respectively on treatment with trichlorosilane in the presence of chloroplatinic acid. Compounds 5 reacted with methanol and pyridine to give the corresponding trimethoxysilane 6. The elemental analysis, IR, ^1H NMR and 19F NMR data of these new compounds were recorded in Table 1-4. The compounds 4, 5 can be used for the treatment of glass surface to render it water-proof and solvent-proof.     

Synthese und flüssigkristalline Eigenschaften 2,6-disubstituierter Naphthaline

Synthesis and Liquid-Crystal Properties of 2,6-Disubstituted Naphthalene Derivatives The syntheses and the mesomorphic properties of a series of novel 2,6-disubstituted naphthalenes are described. 4-[6-(n-Alkyl)-2-naphthyl]benzonitriles 5 and 4-[6-(n-Alkoxy)-2-naphthyl]benzonitriles 8 exhibit widerange nematic mesophases. 6,6′-Di(n-alkyl)-2,2′-binaphthyls 6 have been isolated as by-products from the reaction mixtures of 5 . Some of these novel compounds have polymorphic properties. The esters 13 and 15 of 4-(6-hydroxy-2-naphthyl)benzonitrile show enhanced mesophase stabilities which reach maximum values in the series of α, β-unsaturated esters 15 . The 4-(n-pentyl)benzoate 14 of the same (hydroxynaphthyl)benzonitrile has a melting point of 125° and a clearing point of > 310°. This particular derivative belongs to those liquid-crystalline compounds having the broadest purely nematic-phase range. In addition, (RS)-4-(2-pentyl-6-chromanyl)benzonitrile ( 20 ) and three compounds with two and four laterally arranged CN groups at the bicyclo[2.2.2]octene, bicyclo[2.2.2]octadiene, and the phenyl-ring systems 31 – 33 were synthesized. Only 20 shows mesomorphic properties.     

Reaktionen von Phosphorigsäure-bis(dimethylamid) und Phosphorsaäure-tris(methylamid) mit PCI3

Reactions of Phosphorous Bis(dimethylamide) and Phosphoric Tris(methylamide) with PCI₃ From the products of the reaction between phosphorous bis(dimethylamide) and PCl₃ in the presence of pyridine the pentakis(dimethylamide) of acid can be isolated. The reaction between phosphoric tris(methylamide) and PCl₃ in the presence of pyridine yields crystalline O = P[NCH³? PCl₂]₃ which can be converted into O = P[NCH³? PF₂]₃ with SbF₃ or AsF₃. The nmr data of the new compounds and some by-products of the reaction are given and discussed.     

4-Alkoxy-2-hydroxy-4′-vinylbenzophenones,ultraviolet-absorbing monomers

2,4-Dihydroxy-4′-vinylbenzophenone (I) and its 4-alkyl ethers (II), Me, Et, n-Bu, n-Oct, and n-dodecyl, were prepared in three steps by Hoesch synthesis, starting with p-(2-bromoethyl) benzonitrile and resorcinol and its monoalkyl ethers. I and its precursor 2,4-dihydroxy-4′-(2-bromoethyl) benzophenone were also converted into their 4-alkyl ethers with alkyl halides in dimethylformamide (DMF) in the presence of sodium hydrogen carbonate. Copolymerizations of I and II with styrene took place smoothly with satisfactory conversions to yield copolymers with ε-values around 10⁴ L/mol cm^?1 per benzophenone unit over the ultraviolet (UV) range of 235–340nm.     

Koordinationsverbindungen von Bortrialkylen. II. Zur Komplexbildung zwischen Bortriallylen und tertiären Aminen

Coordination Compounds of Boron Trialkyls. II. On the Complex Formation between Boron Triallyls and Tertiary Amines It is reported on complexes of triallyl, trimethallyl, and tricrotyl boron with N,N-,N′,N′-tetraethylethylene diamine, pyridine, and 2,2′-bipyridyl. Whilst only 1:1 complexes exist with pyridine, 1:1 and 2:1 complexes are formed with tetraethylethylene diamine. Bipyridyl reacts with triallyl boron with formation of the boronium salt [(all)₂B(dipy)][B(all)₄].     

Additionen von Stickstoffbasen an cyclische Organoborsäureester

Additive-Reactions of Nitrogen Bases to Cyclic Esters of Organoboric Acids The reaction of BBr₃, C₆H₅BCl₂ and CH₃BBr₂ with Diols respectively Dithiols yields 2-Bromo- and 2-Organo-1,3,2-diheteroborolanes, -borinanes and -boroles. These compounds and also non cyclic esters and thioesters of organoboric acids are reacted with pyridine, 2-picoline, 4-picoline and 2,4,6-collidine and thereby the enthalpie (ΔH) is measured. From these values it is tried to conclude on Lewis acidity of the boron atom in the different compounds.     

Preparations and electrochemical properties of pyrazine-bridged ruthenium-binuclear complexes exhibiting molecular hysteresis

Three binuclear Ru complexes cis-,cis-[(NH3)4(L)Ru-pz-Ru(NH3)4(dmso)](PF6)4 (L = NH3 (4), pyridine (5), benzonitrile (6); dmso = dimethyl sulfoxide) have been prepared, and their electrochemical behavior, exhibiting molecular hysteresis, is reported. Simulations of cyclic voltammograms and thin-layer cyclic voltammograms have provided redox potentials, isomerization rates, and interconversion rates of the complexes. The rates of the conversions between two isomeric intermediate states have been determined to be5 x 10(-6) and 4 x 10(-4) s(-1) for the complex 4, 4 x 10(-5) and 4 x 10(-4) s(-1) for the complex 5, and 2 x 10(-4) and 5 x 10(-5) s(-1) for the complex 6. The equilibrium parameters between these states are discussed in relation to the redox potentials of the complexes.     

Nuclear magnetic resonance of oriented molecules in lyotropic liquid crystalline media: Pyridine, 4-cyanopyridine and benzonitrile

Proton distance ratios for pyridine, benzonitrile and 4-cyanopyridine have been obtained in a potassium laurate lyotropic mesophase and compare favorably with values for different thermotropic solvents. Order matrices indicate a preference for the C_2v symmetry axis of the molecules to be aligned along the optical axis of the mesophase.     

Electrochemistry and spectroelectrochemistry of meso-substituted free-base corroles in nonaqueous media: reactions of (Cor)H3, [(Cor)H4]+, and [(Cor)H2]-

Eleven free-base corroles with different electron-donating or electron-withdrawing meso substituents were characterized as to their electrochemistry and UV-visible spectroscopy in benzonitrile (PhCN) or pyridine containing tetra-n-butylammonium perchlorate (0.1 M). Six forms of the compounds with different numbers of protons and/or oxidation states were spectroscopically identified and are represented as (Cor)H3, (.Cor)H2, [(Cor)H2]-, [(.Cor)H2]2-, [(Cor)H4]+, and [(.Cor)H4]2+, where Cor is a trianionic corrole macrocycle. The electrochemistry and UV-visible properties are a function of corrole basicity, solvent basicity, and types or sizes of the meso substituents, and the compounds could be subdivided into one of two different groups, one of which comprises sterically hindered corroles and another that does not. The electroactive species in PhCN is (Cor)H3, whereas in pyridine, one inner proton dissociates, generating a mixture of (Cor)H3, [(Cor)H2]-, and pyH+. The addition of one electron to [(Cor)H2]- reversibly gives the [(.Cor)H2]2- pi-anion radical, whereas a reversible oxidation of the same species gives the neutral radical (.Cor)H2. The first one-electron reduction of (Cor)H3 occurs at the macrocycle in PhCN, but the initial product rapidly converts to [(Cor)H2]-, which undergoes additional reversible redox reactions at the conjugated pi-ring system. The first oxidation of (Cor)H3 in PhCN leads to a mixture of (.Cor)H2 and [(Cor)H4]+, both of which could be further oxidized or reduced. The UV-visible spectra of [(Cor)H4]+ were measured in PhCN after titrations with trifluoroacetic acid, after which selected samples were examined as to their electrochemistry. The HOMO-LUMO gaps of [(Cor)H2]-, (Cor)H3, and [(Cor)H4]+ were also determined.     

12. Anil-Synthese. 17. Mitteilung. Über die Herstellung von styryl-derivaten des 2-phenyl-4H-1,2,4-triazolo [1,5-a]pyridins

Preparation of styryl derivatives of 2-phenyl-4H-1,2,4-triazolo [1,5-a]pyridine 7-Methyl-2-phenyl- and 2-(3-chloro-4-methylphenyl)-4H-1,2,4-triazolo[1,5-a]-pyridines react with anils of aromatic aldehydes in the presence of dimethyl-formamide and potassium hydroxide at 20–45° to yield the 2-phenyl-7-styryl- and 2-(2-chloro-stilben-4-yl)-4H-1,2,4-triazolo [1,5-a]pyridines respectively (‘Anil Synthesis’). Further, the Schiff's bases derived from o-chloroaniline and 2-(p-formyl-phenyl)- and 7-formyl-2-phenyl-4H-1,2,4-triazolo [1,5-a]pyridine yield, with methyl- and with p-tolyl-substituted heterocycles, the corresponding heterocyclic substituted styryl and stilbenyl derivatives.     

Totalsynthese von Decarboxybetalainen durch photochemische Ringöffnung von 3-(4-Pyridyl)alanin

Total Synthesis of Decarboxybetalaines by Photochemical Ring Opening of 3-(4-Pyridyl)alanine A photochemical approach is presented for the total synthesis of the decarboxybetalaines, which were previously known from the mild decarboxylation of the natural plant colorants, the betalaines: Irradiation of rac-3-(4-pyridyl)alanine ( 1 ) yielded the rac-2-decarboxybetalamic-acid-imine ( 4 , 86%), presumably via a Dewar pyridine 2 , a cyclic aminal 3 and an electrocyclic ring opening. The imine-zwitterion 4 was treated with three amines, namely (S)-cyclodopa ( 6 ), (S)-proline ( 7 ), and indoline ( 8 ), to afford three decarboxybetalaines, namely (2S)-17-decarboxybetanidine ( 9 , red, 34%), (2S)-13-decarboxyindicaxanthine ( 10 , yellow, 56%), and rac-16-decarboxyindobetalaine ( 11 , orange, 78%), respectively. The structures of these coloring matters were confirmed by their electrophoretic behavior and their spectroscopic properties. 17-Decarboxybetanidine 9 was shown to be a ca. 1:1 mixture of two C(15)-epimers 9a and 9b , separable by chromatography. The configuration of 9a was determined as (2S, 15S) and that of 9b as (2S, 15R), by correlating their optical rotations with those of betanidine ( 12a ) and isobetanidine ( 12b ), respectively. The decarboxybetalaines 9 , 10 , and 11 did not show the double-bond isomerism at C(β), (Cγ) of the chromophore which had been found characteristic for the corresponding betalaines 12 , 13 , and 14 .     

Synthese von Magnesium-bis[N,N′-bis(trimethylsilyl)benzamidinat] als Bis(THF)- und Benzonitril-Addukt

Synthesis of Magnesium Bis[N,N′ -bis(trimethylsilyl)benzamidinate] as both Bis(THF) and Benzonitrile Adduct Magnesium bis[bis(trimethylsilyl)amide] 1 , reacts with benzonitrile in toluene at room temperature to yield magnesium bis[N,N′-bis(trimethylsilyl)benzamidinate]-benzonitrile(1/1) 2 . Addition of THF leads to a quantitative substitution of the benzonitrile ligand by two THF molecules. The performance of the addition reaction in THF yields magnesium bis[N,N′-bis(trimethylsilyl)benzamidinate] · THF(1/2) 3 . The upper benzonitrile complex 2 , crystallizes in the orthorhombic space group Pbcn with {a = 1383.2(2); b = 2589.1(4); c = 1133.7(1) pm; Z = 4}. The magnesium atom is coordinated distorted trigonal-bipyramidal, where the benzonitrile ligand lies within the equatorial plane. The axial bound nitrogen atom of the benzamidinate substitution shows with a value of 213 pm a slightly longer bond distance to the metal center than the one in the equatorial plane (210 pm). The steric strain within the benzamidinate ligand leads to an elongation of the silicon atoms out of the 1,3-diazaallylic moiety under an enlargement of the C? N? Si angle to 131°.     

Über die acetolysenprodukte der cyanhydrine von 4-pyridazoin und 4-pyridoin: Struktur und ungewöhnliche reaktivität 9. Mitteilung über pyridazine

4-Pyridazoinecyanohydrin was found to be converted into the 1,4-dihydropyridazine derivative 2a on treatment with acetic anhydride. Structures of 2a and the corresponding 4-pyridine derivative 2b were assigned on the basis of spectroscopic data. Chromatography of 2a on silica gel using methanol as eluent yielded methyl 4-pyridazinecarboxylate. The pyridine derivative 2b under similar conditions was converted into a mixture of methyl isonicotinate and 4-pyridinylmethyl acetate. Mechanisms of these unexpected reactions are discussed.     

Effect of Bulkiness on Reversible Substitution Reaction at MnII Center with Concomitant Movement of the Lattice DMF: Observation through Single‐Crystal to Single‐Crystal Fashion

The porous coordination polymer ({[Mn(L)H₂O](H₂O)_1.5(dmf)}_n, 1 ) (DMF=N,N‐dimethylformamide) exhibits variety of substitution reactions along with movement of lattice DMF molecule depending upon bulkiness of the external guest molecules. If pyridine or 4‐picoline is used as a guest, both lattice and coordinated solvent molecules are simultaneously substituted (complexes 6 and 7 , respectively). If a bulky guest like aniline is used, a partial substitution at the metal centers and full substitution at the channels takes place (complex 8 ). If the guest is 2‐picoline (by varying the position of bulky methyl group with respect to donor N atom), one Mn^II center is substituted by 2‐picoline, whereas the remaining center is substituted by a DMF molecule that migrates from the channel to the metal center (complex 9 ). Here, the lattice solvent molecules are substituted by 2‐picoline molecules. For the case of other bulky guests like benzonitrile or 2,6‐lutidine, both the metal centers are substituted by two DMF molecules, again migrating from the channel, and the lattice solvent molecules are substituted by these guest molecules (complex 10 and 11 , respectively). A preferential substitution of pyridine over benzonitrile (complex 12 ) at the metal centers is observed only when the molar ratio of PhCN:Py is 95:5 or less. For the case of an aliphatic dimethylaminoacetonitrile guest, the metal centers remain unsubstituted (complex 13 ); rather substitutions of the lattice solvents by the guest molecules take place. All these phenomena are observed through single crystal to single crystal (SC–SC) phenomena.