ZIB

1

Electronic Resource

[2.2](2,6)- and [2.2](2,5)Pyrazinophanes: Synthesis and Molecular Structure (1990)

Eiermann, Uwe ; Krieger, Claus ; Neugebauer, Franz A. ; [et al.]

Weinheim : Wiley-Blackwell

Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 523-533

add to mindlist on the mindlist

Details

ISSN: 0009-2940

Keywords: Hofman 1,6-elimination / Pyrazine derivatives / [2.2]Pyrazinophanes ; Chemistry ; Inorganic Chemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: The title compounds 1-3 and their methyl derivatives 4-7 were synthesized 2,11-dithia[3.3]pyrazinophanes 24-26 or by Hofmann 1,6-elimination of the appropriate [(5-methyl-2-pyrazinyl)methyl]trimethylammonium hydroxides followed by dimerization of the generated 2,5-dihydro-2,5-dimethylenepyrazines. α-Chlorination of the methylpyrazines 8-10 with N-chlorosuccinimide gave the required precursors 11, 12, 14, 17 and 18. The results of the X-ray structure determinations for 1-4 and 7 which indicate an unequivocal isomer assignment are discussed with regard to steric strain in these molecules. The electronic spectra of the pyrazinophanes 7-7 are reported and compared with those of the parent methylpyrazines.

Additional Material: 6 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/cber.19901230319

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

2

Electronic Resource

1,8-Bis(diphenylamino)- and 1,8-Bis(methylphenylamino)naphthalene: Molecular Structure and Dynamic Behavior (1992)

Rimmler, Gösta ; Krieger, Claus ; Neugebauer, Franz A.

Weinheim : Wiley-Blackwell

Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 723-728

add to mindlist on the mindlist

Details

ISSN: 0009-2940

Keywords: 1,8-Diaminonaphthalenes, X-ray structure analysis of, conformational barriers of, dynamic behavior of ; Chemistry ; Inorganic Chemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: The title compounds 2 and 3 have been synthesized from 1,8-diaminonaphthalene. The molecular structure of 2 has been determined by X-ray structure analysis and is discussed with regard to the arrangement of the peri-diphenylamino substituents in the crystalline state and the steric strain in the molecule. NMR studies of 3 reveal two conformational processes. Their nature is discussed and barriers are reported.

Additional Material: 3 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/cber.19921250327

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

3

Electronic Resource

[2.2](2,5)Pyrimidinophanes: Synthesis and molecular structure (1990)

Eiermann, Uwe ; Krieger, Claus ; Neugebauer, Franz A.

Weinheim : Wiley-Blackwell

Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 1885-1889

add to mindlist on the mindlist

Details

ISSN: 0009-2940

Keywords: Pyrimidine derivatives ; Sulfur extrusion, photolytic ; Pyrimidinophanes ; Chemistry ; Inorganic Chemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: The title compounds 1 and 2 are synthesized by photolytic sulfur extrusion from the 2,11-dithia[3.3](2,5)pyrimidinophane 17. The molecular structures of 1 and 2 are determined by X-ray structure analysis and are discussed with regard to the steric strain in these molecules. Thermolysis of [(5-methyl-2-pyrimidinyl]methyl]- or [(2-methyl-5-pyrimidinyl)methyl]-trimethylammonium hydroxide (10 or 11) does not generate 1 and 2. α-Chlorination of 2,5-dimethylpyrimidine (3) with N-chlorosuccinimide provides the required precursors 4-6.

Additional Material: 2 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/cber.19901230921

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

4

Electronic Resource

7H-benz [kl]acridin-7-ylium closed-shell ion produced from 1,8-bis(phenylamino)naphthalenes under electron impact: Tandem mass spectrometric structure elucidationProximity Effects in the Mass Spectra of Crowded N-Phenyl-substituted 1,8-Diaminonaphthalenes Part VII. (1993)

Rentzea, Marina ; Rimmler, Gösta ; Neugebauer, Franz A.

Chichester : Wiley-Blackwell

Biological Mass Spectrometry 28 (1993), S. 494-498

add to mindlist on the mindlist

Details

ISSN: 0030-493X

Keywords: Chemistry ; Analytical Chemistry and Spectroscopy

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: Not only strongly basic aromatic amines such as ‘proton sponges’ show characteristic [M - Me2NH - H]+ peaks corresponding to cyclization to stable heterocyclic ions under electron impact. The fragmentation of the title compounds, which are weak bases, leads to [M - RNH2 - C6H5]+ heteroaromatic ions. These are the 7-phenyl-7H-benz[kl]acridine radical cation and the delocalized stable 7H-benz[kl]acridin-7-ylium ion as shown by unimolecular metastable ion spectra, collision-induced decomposition (CID) tandem mass spectrometry (MS/MS) and accurate mass measurements. The high-collision-energy CID tandem mass spectra of these ions are perfectly superimposable on those of the ions produced by the reference substance, 7-phenyl-7H-benz[kl]acridine obtained as a by-product in the Ullmann phenylation of 1,8-diaminonaphthalene. This combination of MS/MS experiments also provides strong support for the gas-phase reaction mechanism leading to the benz[kl]acridine ions and for the structures of these ions.

Additional Material: 3 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/oms.1210280505

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

5

Electronic Resource

Über hochacide KohlenwasserstoffeHerrn Prof. Dr. Georg Wittig zum 65. Geburtstag (1962)

Kuhn, Richard ; Fischer, Herbert ; Neugebauer, Franz A. ; [et al.]

Weinheim : Wiley-Blackwell

Liebigs Annalen 654 (1962), S. 64-81

add to mindlist on the mindlist

Details

ISSN: 0075-4617

Keywords: Chemistry ; Organic Chemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: Die CH-Acidität von 1.1.3.3-Tetraphenyl-propen und von 1.1.5.5-Tetraphenyl-pentadien nimmt um viele Zehnerpotenzen zu, wenn mindestens 2 der Phenylreste zu einem Biphenylenrest eingeebnet werden. Derartige Kohlenwasserstoffe geben in geeigneten Lösungsmitteln bereits mit 0.1 n wäßrigen Laugen tieffarbige Salze, die bei Ausschluß von Luft beständig sind. Die durch Entladung der roten bzw. blauen Anionen mit K3Fe(CN)6 resultierenden paramagnetischen Radikale sind gelb und fallen durch ihre geringe Reaktionsgeschwindigkeit mit O2 auf. Im Falle des 1.1.5.5-Bis-biphenylen-pentadiens-(1.4) liefert das mesomere Anion mit Methyljodid zwei verschiedene Methylderivate. - Es wird eine qualitative theoretische Deutung für den Einfluß der Biphenylenbindungen auf die Säuredissoziationskonstanten vorgeschlagen.

Additional Material: 2 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/jlac.19626540109

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

6

Electronic Resource

1,4,5,8-Tetrakis(dimethylamino)naphthalin: Synthese, Struktur, „Protonenschwamm“- und Elektronendonor-EigenschaftenNeue „Protonenschwamm“-Verbindungen, 10. Mitteilung. - 9. Mitteilung: H. A. Staab, M. A. Zirnstein, C. Krieger, Angew. Chem. 101 (1989) 73; Angew. Chem. Int. Ed. Engl. 28 (1989) 86. (1991)

Barth, Thomas ; Krieger, Claus ; Neugebauer, Franz A. ; [et al.]

Weinheim : Wiley-Blackwell

Zeitschrift für die chemische Industrie 103 (1991), S. 1006-1008

add to mindlist on the mindlist

Details

ISSN: 0044-8249

Keywords: Chemistry ; General Chemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Additional Material: 3 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/ange.19911030828

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

7

Electronic Resource

ESR and ENDOR study of 2,3-dihydro-1-oxo-1λ4,2,3,5-thiatriazol-3-yl radicals (1992)

Neugebauer, Franz A.

Chichester : Wiley-Blackwell

Organic Magnetic Resonance 30 (1992), S. 84-86

add to mindlist on the mindlist

Details

ISSN: 0749-1581

Keywords: ESR ; Nitrogen-centred radicals ; 2,3-Dihydro-1-oxo-1λ4,2,3,5-thiatriazol-3-yl radicals ; Chemistry ; Analytical Chemistry and Spectroscopy

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: Dehydrogenation of 2,5-dihydro-1,2,3,5-thiatriazole 1-oxides with thermally formed bis(4-methylphenyl)aminyl generated 2,3-dihydro-1-oxo-1λ4,2,3,5-thiatriazol-3-yl radicals. ESR, ENDOR and triple resonance studies in combination with 15N labelling yielded the magnitude and assignment of all 1H and 14N hyperfine coupling (HFC) constants. The radicals have a basic five-π-electron amidrazon-2-yl structure with the highest spin density at N-2.

Additional Material: 3 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/mrc.1260300117

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

8

Electronic Resource

1,4,5,8-Tetrakis(dimethylamino)naphthalene: Synthesis, Structure, “Proton Sponge” and Electron Donor PropertiesNovel “Proton Sponge” Compounds, Part 10. - Part 9: H. A. Staab, M. A. Zirnstein, C. Krieger, Angew. Chem. 101 (1989) 73; Angew. Chem. Int. Ed. Engl. 28 (1989) 86. (1991)

Barth, Thomas ; Krieger, Claus ; Neugebauer, Franz A. ; [et al.]

Weinheim : Wiley-Blackwell

Angewandte Chemie International Edition in English 30 (1991), S. 1028-1030

add to mindlist on the mindlist

Details

ISSN: 0570-0833

Keywords: Chemistry ; General Chemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Additional Material: 3 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/anie.199110281

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext