Twisted intramolecular charge transfer of dimethylaminobenzonitrile in micellar environments - A way to look at the orientation of the probe within the apolar microenvironment

Twisted intramolecular charge transfer (TICT) of p-N,N-dimethylaminobenzonitrile (DMABN) in the photoexcited state has been studied in aqueous cetyl trimethylammonium bromide (CTAB, cationic) and sodium dodecyl sulphate (SDS, anionic) micellar solutions. The TICT process is found to be affected by the surface charge of the micellar aggregates. A comparative study of the enhancement of the TICT and the locally excited (LE) or non-polar (NP) emission yields in the two micellar solutions establishes that the probe (DMABN) resides within the micellar environment keeping the dimethylamino group at the micellar periphery and the other end deep in the micellar core. Multiple CMCs for both the micellar systems have been reported. (C) 1997 Elsevier Science B.V.