Preparation and crystal structure of [Bi3I(C4H8O3H2)2(C4H8O3H)5]2Bi8I30 containing the novel polynuclear [Bi8I30] anion

Preparation and crystal structure of the novel compound [Bi₃I(C₄H₈O₃H₂)₂(C₄H₈O₃H)₅]₂Bi₈I₃₀ are reported. The title compound is prepared by heating of BiI₃ and diethylene glycol at 413 K in a sealed quartz glass tube filled with argon. Deep red single crystals are grown and applied to perform X-ray powder diffraction and X-ray single-crystal diffraction measurements. The compound crystallizes triclinic with space group P-1: Z=2, a=13.217(1) Å, b=15.277(1) Å, c=22.498(1) Å, α=84.33(1), β=73.18(1), γ=67.48(1). [Bi₃I(C₄H₈O₃H₂)₂(C₄H₈O₃H)₅]₂Bi₈I₃₀ comprises the novel polynuclear [Bi₈I₃₀]⁶⁻ anion and [Bi₃I(C₄H₈O₃H₂)₂(C₄H₈O₃H)₅]³⁺ as the cation. Cation as well as the anion can be assumed to represent intermediates between solid BiI₃ and BiI₃ completely dissolved in diethylene glycol.     

Zum Mechanismus der Umlagerung von N-Aryl-S,S-dimethylsulfimiden zu o-Methylthiomethylanilinen

Zusammenfassung N-Aryl-S,S-dimethylsulfimide können entweder in aprotischen Lösungsmitteln in Gegenwart von Basen (Triäthylamin) oder in protischen Lösungsmitteln (Alkohole, Wasser) ohne Zusatz von Basen in o-Methylthiomethylaniline umgelagert werden. Die Geschwindigkeit der Umlagerung wird bestimmt von der Abspaltung eines Protons aus einer S-Methylgruppe und von der Lage des Gleichgewichts für die Protonierung am Stickstoffatom, was aus einem kinetischen Isotopeneffekt und aus der Richtung des Einflusses von p-Substituenten geschlossen wurde. Die eigentliche Umlagerung des intermediären S-Ylids ist rascher als seine Reprotonierung durch protische Lösungsmittel und entspricht einer sigmatropen [2,3]-Verschiebung.

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On the mechanism of the rearrangement of N-Aryl-S,S,-dimethyl sulfimides to o-methylthiomethyl anilines

N-Aryl-S,S-dimethyl sulfimides may be rearranged to yield o-methylthiomethyl anilines either in aprotic solvents in presence of bases (triethyl amine) or in protic solvents (alcohols, water) without addition of base. The rate of the rearrangement is determined by the rate of proton abstraction from one of the S-methyl groups as well as by the position of the equilibrium for protomation of the nitrogen atom, as indicated by kinetic isotope effects and the influence of p-substituents, respectively. The rearrangement of the intermediate S-ylide is faster than its reprotonation by protic solvents and represents a sigmatropic [2.3]-migration.

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Mit 4 Abbildungen

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Herrn Prof. Dr.O. Kratky zum 70. Geburtstag gewidmet.

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7. Mitt.:P. Claus, W. Vycudilik undW. Rieder, Mh. Chem.102, 1571 (1971).

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Teile der Ergebnisse über die Umlagerung des N-4-Chlorphenyl-S,S-dimethylsulfimids sind in der DissertationW. Rieder, Univ. Wien (1971), enthalten.     

Formation of modified cytosine residues in the presence of depurinated DNA

[Chemical reaction: See text] Depurination is an important degradation pathway for antisense phosphorothioate oligonucleotides under conditions of thermal stress. We present evidence showing that depurinated oligonucleotides react with cytosine-containing sequences giving products containing a 6-(2-deoxy-beta-D-erythro-pentofuranosyl)-3-(2-oxopropyl)imidazo[1,2-c]pyrimidin-5(6H)-one residue. Further, we demonstrate that the same product is formed upon treatment of 2'-deoxycytidine with 4-oxo-2-pentenal, the latter being an expected byproduct of serial elimination reactions at apurinic sites. In addition to being important for synthetic oligonucleotides, apurinic site formation in cellular DNA is a common occurrence. Because repair of these sites can result in the production of 4-oxo-2-pentenal, it is interesting to speculate whether 6-(2-deoxy-beta-D-erythro-pentofuranosyl)-3-(2-oxopropyl)imidazo[1,2-c]pyrimidin-5(6H)-one residues can form in vivo.     

Synthesis of new uracil non‐nucleoside derivatives as potential inhibitors of HIV‐1

6‐(2‐Phenylethyl) and 6‐cyclohexyl 5‐cyanouracils ( 1a,b ) were synthesized and reacted with chloromethyl ethyl ether, benzyl chloromethyl ether, chloromethyl methyl sulfide and (2‐acetoxyethoxy)methyl bromide. New uracil analogues of (S)‐DHPA were synthesized by reaction of compounds ( 1a,b ) with ((S)‐2,2‐dimethyl‐1,3‐dioxolane‐4‐yl) alkyl p‐toluenesulfonate.     

Atmospheric chemistry of hydrofluoroethers: Reaction of a series of hydrofluoroethers with OH radicals and Cl atoms, atmospheric lifetimes, and global warming potentials

The kinetics of the OH radical and Cl atom reactions with nine fluorinated ethers have been studied by the relative rate method at 298 K and 1013 hPa using gas chromatography-mass spectroscopy (GC-MS) detection: k(OH + CH3CH2OCF3) = (1.55 +/- 0.25) x 10(-13), k(OH + CF3CH2OCH3) = (5.7 +/- 0.8) x 10(-13),k(OH + CF3CH2OCHF2) = (9.1 +/- 1.1) x 10(-15), k(OH + CF3CHFOCHF2) = (6.5 +/- 0.8) x 10(-15), k(OH + CHF2CHFOCF3) = (6.8 +/- 1.1) x 10(-15), k(OH + CF3CHFOCF3) < 1 x 10(-15), k(OH + CF3CHFCF2OCHF2) = (1.69 +/- 0.26) x 10(-14), k(OH + CF3CHFCF2OCH2CH3) = (1.47 +/- 0.13) x 10(-13), k(OH + CF3CF2CF2OCHFCF3) < 1 x 10(-15), k(Cl + CH3CH2OCF3) = (2.2 +/- 0.8) x 10(-12), k(Cl + CF3CH2OCH3) = (1.8 +/- 0.9) x 10(-11), k(Cl + CF3CH2OCHF2) = (1.5 +/- 0.4) x 10(-14), k(Cl + CF3CHFOCHF2) = (1.1 +/- 1.9) x 10(-15), k(Cl + CHF2CHFOCF3) = (1.2 +/- 2.0) x 10(-15), k(Cl + CF3CHFOCF3) < 3 x 10(-15), k(Cl + CF3CHFCF2OCHF2) < 6 x 10(-16), k(Cl + CF3CHFCF2OCH2CH3) = (3.1 +/- 1.1) x 10(-12), and k(Cl + CF3CF2CF2OCHFCF3) < 3 x 10(-15) cm3 molecule(-1) s(-1). The error limits include three standard deviations (3 sigma) from the statistical data analyses, as well as the errors in the rate coefficients of the reference compounds that are used. Infrared absorption cross sections and estimates of the trophospheric lifetimes and the global warming potentials of the fluorinated ethers are presented. The atmospheric degradation of the compounds is discussed.     

Light Scattering Study of Turbid Heat-Set Globular Protein Gels Using Cross-Correlation Dynamic Light Scattering

The structure factor of aqueous solutions of the globular protein β-lactoglobulin was determined as a function of heating time at 76°C. We show how the effect of multiple scattering on the scattered light intensity can be effectively corrected using cross-correlation dynamic light scattering even if the transmission is only 1%. The structure factor of aggregated and gelled proteins can be described by the Ornstein–Zernike equation. The system is characterized by a correlation length that increases with heating time and stabilizes some time after the gel is formed. The correlation length of the protein gels decreases with decreasing concentration. Measurements after progressive dilution of a sample close to the gel point showed that the protein aggregates are initially interpenetrated and disinterpenetrate upon dilution.     

Halogenierte Pyridine I. Die Herstellung von 3-Halogenmethylpyridinen aus dimerem Acrylnitril

Halogenated pyridines I. The synthesis of 3-halogenomethyl pyridines from dimeric acrylonitrile . α-Methyleneglutaronitril, a linear dimerization product of acrylonitrile is a cheap, commercially available starting material for a new synthesis of 3-halogenomethyl-2, 6-dihalogeno- or 2,5,6-trihalogenopyridines prepared in two and three step reactions, respectively. The properties of this new class of halogenated pyridines are discussed.     

Dinucleotides of 4′-C-vinyl- and 5′-C-allylthymidine as substrates for ring-closing metathesis reactions

Thymidine derivatives containing a 4′-C-vinyl group or a 5′-C-allyl group are synthesized and used as building blocks for three different dinucleotides. These are evaluated as substrates for ring-closing metathesis cyclisations, and a protected 5′-C-allylthymidine homo-dimer is found to be the most reactive. A protected precursor for a conformationally restricted cyclic dinucleotide with a four carbon 5′-C to 5′-C connection is hereby efficiently obtained, whereas a corresponding three carbon 4′-C to 5′-C connection is obtained in a lower yield.