Dual fluorescence of 4,4′-bis(dimethylamino)benzophenone. Effects of specific and nonspecific interaction on the formation of twisted intramolecular charge transfer

✍ Scribed by Lian C.T. Shoute

• Book ID: 103033664
• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 410 KB
• Volume: 195
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)86145-8

✦ Synopsis

4,4'-bis (dimethylamino) benzophenone (BDMABP) emits dual fluorescence. The dipole-moment change determined from the solvatochromic shift is 4.0 D in alcohols and 10.4 D in polar aprotic solvents. Both short and long wavelength fluorescence is observed in I-PrOH: DMSO mixed solvents. The Stokes shifts, the radiative rate constants, and the dipole-moment change indicate that BDMABP emits planar intramolecular charge transfer (ICT) fluorescence in alcohol and twisted intramolecular charge transfer (TICT) fluorescence in polar aprotic solvents. The study demonstrates that nonspecific dielectric interaction facilitates the formation of the TICT state and specific interaction, such as hydrogen bonding between solute and solvent, interferes with its formation.