Photochemie substituierter Cycloheptatriene. XV. Zur Charakterisierung der Elektronischen Übergänge in 1-Aryl-4-(p-dimethylaminophenyl)-cycloheptatrienen

✍ Scribed by Dr. sc. W. Abraham; Dipl.-Chem. M. Kupfer; Prof. Dr. D. Kreysig

• Book ID: 105352503
• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: English
• Weight: 537 KB
• Volume: 324
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/prac.19823240508

✦ Synopsis

Photochemistry of Substituted Cycloheptatrienes. XV. About the Characterization of the Electronic Transitions in 1‐Aryl‐4‐(p‐dimethylaminophenyl)‐cycloheptatrienes

The absorption spectra of the title compounds are discussed in dependence on polarity of the solvent and its ability to form hydrogen bonds. The results suggest a hybridization of the N‐atom of the dimethylamino group between sp^3^ and sp^2^ in the ground state. Contrary to this, the nitrogen has sp^2^‐hybridization in the short wavelength (SE) fluorescing state. In a second fluorescence state the geometry of the seven‐membered ring should change. Therefore the viscosity of the solvents influences both the position and the quantum yield of this long wavelength emission (LE). The influence of polarity and viscosity of the solvents is described by multiple regression. The temperature dependence of fluorescence quantum yields is discussed, as well.