Photoelectron Spectra, Electronic Structures, and Conformational Properties of (E)-Stilbene, Styrylthiophenes, and (Thienylethenyl)pyridines

✍ Scribed by Paul Rademacher; Andreas Lars Marzinzik; Klaus Kowski; Michael Edgar Weiß

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 444 KB
• Volume: 2001
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/1099-0690(200101)2001:1<121::aid-ejoc121>3.0.co;2-r

✦ Synopsis

The UV photoelectron spectra of two isomeric styrylthiophenes (5, 6) and six isomeric (thienylethenyl)pyridines (7-12) have been recorded and analyzed, making use of DFT Becke3LYP calculations. The spectra were compared with those of (E)-stilbene (1e) and the isomeric styrylpyridines (2-4), which are π-isoelectronic with 5-12. Using quantum chemical analyses, planar molecular structures were obtained for all these compounds. However, from the separation ∆IP of the ionization bands associated with the π 7 and π 3 MOs, it is possible to make a distinction between planar and twisted molecular structures. Accordingly in these compounds, 2-substituted pyridine rings and 3-substituted thi-