Proximate,syn-Periplanar Bisdiazene Skeletons: Syntheses, Structures, Homoconjugate Reactivity and Photochemistry

Autor: Meinrad Lugan, Horst Prinzbach, Dieter Hunkler, Nikolaus Bahr, Eberhard Beckmann, Kai Exner, Lothar Knothe, Gerhard Fischer, Manfred Keller, Fushun Yang, G. Rihs
Rok vydání: 2000
Předmět:
Zdroj: European Journal of Organic Chemistry. 2000:763-785
ISSN: 1099-0690
1434-193X
Popis: Rigid NN/NN (diazene/diazene) systems (F) consisting of more or less alkylated DBH and DBO chromophoric units (1, 2, X-ray structures), with very short π,π distances [d = 2.849 (1a, av.), 2.822 A (2)] and almost perfect syn-periplanar π,π alignments [ω = 168.6 (1a), 174.2° (2)] as well as the more flexible, less “proximate” metathesis isomers (3a,c, 27a,c, d >4.6 A, ω = 90-100°) have been synthesized. Homoconjugate π,π interaction (in 1, 2, not in 3, 27) is deduced from UV spectroscopic measurements [π π* maxima at 239 (234) nm (sh, 260)], while PE analyses furnished only small interaction parameters (1a
Databáze: OpenAIRE
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