Direct proof of electron transfer in a rigid first generation triphenyl amine core dendrimer substituted with a peryleneimide acceptor

Abstract

The combination of nanosecond transient absorption experiments and single photon timing experiments proved the occurrence of an electron transfer process in the triphenyl amine core dendrimer, N1P₁, by demonstrating the presence of an ion-pair absorption for N1P₁ in solvents of medium polarity. By means of femtosecond transient absorption measurements the rise time of this ion-pair absorption dominated by the radical anion absorption could be determined, resulting in a value of 180 ps in MeTHF and 138 ps in THF. Furthermore, in femtosecond fluorescence upconversion as well as in monochromatic femtosecond transient absorption, a few ps component was resolved which was assigned to a vibrational and solvent relaxation process of the locally excited singlet state of the peryleneimide.