Evolution of absorption, fluorescence, laser and chemical properties in the series of compounds perylene, benzo(ghi)perylene and coronene

Photoinduced products from cold coronene clusters

“…Note that the discharge is switched off when the clusters are ionized by the laser. The laser wavelength of 308 nm is very close to the strong S 0 −→ S β transition of neutral coronene (Nijegorodov et al 2001). Upon absorbing several photons, the coronene is electronically excited and ionized.…”

“…The discharge in the cluster source is switched off, so that only cold neutral coronene clusters enter the first acceleration zone of the RETOF. Thanks to the presence of strong absorption bands in both neutral coronene (Nijegorodov et al 2001) and its cation (Shida 1988) in this energy range, multiple sequential absorption of several photons is expected to occur within the cluster during the laser pulse (typical duration 10 ns). Only two photons are needed to overpass the IP of the coronene monomer, i.e.…”

Synthesis and Structures of Multifunctionalized Helicenes and Dehydrohelicenes: An Efficient Route to Construct Cyan Fluorescent Molecules

“…All dehydro [5]helicene (or naphthoperylene) derivatives showed good solubility in common organic solvents, such as Figure 3, the UV/Vis spectrum of dehydro [5]helicene 10 a in cyclohexane exhibited the maximum absorption band at 436 nm, a bathochromic shift of 51 nm compared to benzoA C H T U N G T R E N N U N G [g,h,i]perylene, [21] which is probably due to the larger conjugated p system and the electron-donating effect of methoxy groups in 10 a. In the fluorescent spectrum, the maximum emission wavelength of 10 a was observed at 478 nm, which was consistent with cyan fluorescence.…”

The synthesis of novel perylene-like dyes and their aggregation properties in Langmuir and Langmuir–Blodgett films

“…the dipole moment of which is directed parallel to the long axis of the molecule [27e29]. Two other absorption bands, one parallel (S 0 / S b ) and one perpendicular (S 0 / S a ) to the molecular long axis, are observed for perylene and its derivatives in UV region [28,29] and were not recorded in our experiment. The position of the maxima and the shape of the band in the visible region do not depend on the substituents.…”