Photoinduced isomerization and charge transfer in trans-1,2-bis(1-methyl-4-pyridinio)ethylene salts

✍ Scribed by T.W. Ebbesen; C.M. Previtali; T. Karatsu; T. Arai; K. Tokumaru

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 376 KB
• Volume: 119
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(85)85374-4

✦ Synopsis

The fluorescence quantum yield and lifetime of trans-l,2-bis-(1-methyl-4-pyridinio)ethylenediperchlorate, t-BPE 2+ (C104 )2, are respectively 0.01 and < 3 ns in CH3CN. The quantum yield of trans to cis photoisomerization is 0.35_+0.07. Iodide complexes the olefin in the ground state with an equilibrium constant of 4.6 M 1 and the charge transfer absorption maximum is at 420 nm. Iodide quenches the olefin fluorescence both by diffusional encounter (Ksv=10 M -1) and through complexation, leading to the formation of t-BPE + and I~ radicals with a quantum yield of 0.10_+ 0.02.