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The role of hydrogen bonding in pseudo-macrocyclic ring formation in 2,6-dimethyl-1,3,5,7-cyclooctatetraene 1,3,5,7-tetracarboxylic acid monohydrate (2000)

Vij, Ashwani ; Palmer, Jennifer L. ; Chauhan, Kamlesh ; [et al.]

Springer

Journal of chemical crystallography 30 (2000), S. 621-626

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ISSN: 1572-8854

Keywords: Carboxylic acids ; cyclooctatetraene ; hydrogen bonding

Source: Springer Online Journal Archives 1860-2000

Topics: Geosciences , Physics

Notes: Abstract 2,6-Dimethyl-1,3,5,7-cyclooctatetraene-1,3,5,7-tetracarboxylic acid 3, C14H14O9, was prepared by thermolysis of the corresponding semibullvalene and characterized by spectroscopic and single-crystal X-ray diffraction studies. The monohydrate of 3 crystallizes in the tetrahedral space group P-4n2, a = 11.0924(3) Å, c = 12.6799(5) Å, V = 1560.15(9) Å3, Z = 4. The cyclooctatetraene ring adopts a tub-shaped conformation with a crystallograpically imposed twofold rotational symmetry, and is composed of localized C=C double bonds in the 1,3,5, and 7 positions with an average interatomic distance of 1.327 (5) Å and C–C single bonds with an average interatomic distance of 1.489(5) Å. The average C=C–C angle in the ring is 122.6(3)°. Each symmetry generated eight-membered ring contains four carboxyl groups, two of which are coplanar with the methyl groups across the C=C ring atoms. However, across the C–C bonds the carboxyl groups and the methyl groups show a torsion angle of 64.3(4)°. The presence of a water molecule in the crystal lattice generates a three-dimensional network of close hydrogen bondings between water and the carboxyl groups of multiple rings. This creates a network of orthogonal 10-membered rings between the 8-membered rings. Two given cyclooctatetraene rings are intermolecularly hydrogen bonded not only directly through their carboxyl groups but also via a bridging water molecule. This effect is rare in polycarboxylic acids and their monohydrates which bond only with water or among themselves.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1023/A:1011981630202

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Perfluorovinyl Morpholine and Perfluorovinyl Pyrrolidine with Nucleophiles and ElectrophilesDedicated to Professor Herbert W. Roesky on the Occasion of his 60th Birthday (1995)

Vij, Ashwani ; Connors, Patrick J. ; Rice, Bobbie L. ; [et al.]

Weinheim : Wiley-Blackwell

Zeitschrift für anorganische Chemie 621 (1995), S. 1865-1874

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ISSN: 0044-2313

Keywords: Perfluorovinyl amine ; X-ray crystal structure ; nucleophile ; electrophile ; Chemistry ; Inorganic Chemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Description / Table of Contents: Reaktion von Perfluorvinyl-Morpholin und Perfluorvinyl-Pyrrolidin mit Nukleophilen und ElektrophilenEs wird die Umsetzung von monofunktionellen und bifunktionellen Nukleophilen sowie des Elektrophils FNO mit Perfluorvinylaminen mitgeteilt. Die Perfluorvinylamine CF=CF2 und CF=CF2 wurden mit Dimethylamin und Diethylamin in Gegenwart kleiner Mengen Wasser umgesetzt zu CHFC(O)N(CH3)2 (1), CHFC(O)N(CH3)2 (2), bzw. CHFC(O)N(C2H5)2 (3). Mit Perfluorvinylpyrrolidin und Perfluorvinylmorpholin ergibt Ethanolamin die cyclischen Produkte CHF (4) bzw. CHF (5). Die Reaktion der Vinylamine mit (CH3)3SiOCH2CF3 in Gegenwart katalytischer Mengen von CsF ergibt cis- (6) und trans- (7) CF=CF(OCH2CF3) sowie cis- (8) und trans-(9) CF=CF(OCH2=CF3). Das elektrophile FNO reagiert langsam mit Perfluorvinylpyrrolidin und Perfluorvinylmorpholin und schneller mit (CH3)3CCF=CF2 zu CF(NO)CF3 (10), CF(NO)CF3 (11) bzw. (CF3)CF(NO)CF3 (12). Die Einkristall-Röntgen-Analyse wird zur Klärung der Produkte der kontrollierten Hydrolyse der Sultone von Perfluorvinylpyrrolidin wie des Sulfonsäureanhydrids C(O)CF2OS(O)2OCF2C(O) (13) eingesetzt. Die Röntgenstruktur von Perfluorbernsteinsäure · Monohydrat (14), die durch Hydrolyse von Perfluorvinylpyrrolidin mit einem Überschuß an Wasser erhalten wurde, wird erstmals mitgeteilt.

Notes: In this study, both monofunctional and bifunctional nucleophiles, as well as the electrophile FNO, are reacted with perfluorovinyl amines. The perfluorovinyl amines CF=CF2 and CF=CF2 have been reacted with dimethylamine and diethylamine in the presence of small amounts of water to give CHFC(O)N(CH3)2 (1), CHFC(O)N(CH3)2 (2), and CHFC(O)N(C2H5)2 (3). With perfluorovinyl pyrrolidine and perfluorovinyl morpholine, ethanolamine gives the cyclized products CHF (4) and CHF (5), respectively. Reaction of the vinyl amines with (CH3)3SiOCH2CF3 in the presence of catalytic amounts of CsF results in the formation of cis- (6) and trans- (7) CF=CF(OCH2CF3) and cis- (8) and trans- (9) CF=CF(OCH2CF3). The electrophile FNO reacts slowly with perfluorovinyl pyrrolidine and perfluorovinyl morpholine, and more rapidly with (CF3)3CCF=CF2 to give CF(NO)CF3 (10), CF(NO)CF3 (11) and (CF3)3CF(NO)CF3 (12), respectively. Single crystal X-ray analysis is used to confirm the identity of the product obtained from the controlled hydrolysis of the sultone of perfluorovinyl pyrrolidine as the sulfonic acid anhydride C(O)CF2OS(O)2OCF2C(O) (13). The X-ray crystal structure of perfluorosuccinic acid monohydrate (14), which is obtained when the perfluorovinyl pyrrolidine sultone is hydrolyzed in excess water, is also reported for the first time.

Additional Material: 4 Ill.