CHARGE-TRANSFER INTERACTIONS IN DONOR-DONOR DIARYLAMINES

The photophysical properties of 4-aminodiphenylamine (1) and two deriv ates 4,4'-diaminodiphenylamine (2) and 4-cyanodiphenylamine (3) are st udied by absorption- as well as steady-state- and time-resolved fluore scence spectroscopy. 1 can be considered as a model oligomer of polyan iline. It is a central problem which properties of this conducting pol ymer can already be explained on the basis of small oligomers Like 1 a nd derivates 2 and 3 with weakened and strengthened donor-acceptor pro perties. The investigations on I indicate dual fluorescence and charge separation in polar solvents, connected with an excited state equilib rium. The relative population of the charge transfer species correlate s with the substituent-induced changes of donor-acceptor properties in 2 and 3.