Ultrafast Photochromic Reactions of Structurally Modified Furylfulgides and a Bridged Azobenzene

In this Thesis, the effect of structural modifications on the ultrafast dynamics and photochemical properties of furylfulgides and azobenzenes, as two important classes of photochromic switches, was investigated by femtosecond time-resolved transient absorption spectroscopy (fsTAS). The parent compound of the furylfulgides (MeF) was systematically modified by steric and electronic effects with a bulky isopropyl substituent (iPrF) or by intramolecular bridging (7rF) at the hexatriene/cyclohexadiene chromophore and by benzannulation of the furyl ring (MeBF), respectively. The second task was the investigation of the photo-induced isomerization of a highly constrained bridged azobenzene derivative (brAB), which can be regarded as a new improved class of azobenzenes.