Theoretical evaluation of potential surfaces, equilibrium geometries and vibronic transition intensities of excimers: the pyrene crystal excimer

Enhanced Photoluminescence of Mesostructured Organosilica Films with a High Density of Fluorescent Chromophores

“…The formation of highly emissive excimers in the mesostructured organosilica films can be explained by considering the steric effects of the chromophores. The excimer state of pyrene is theoretically described as an exciton‐resonance state, which is responsible for the parallel arrangement of the molecular axes of the pyrenes . The excimer of pyrenes in a solid state has also been reported to form a sandwich geometry with a distance of ≈3.3 Å and a slight displacement .…”

“…[34,35] The excimer of pyrenes in a solid state has also been reported to form a sandwich geometry with a distance of ≈3.3 Å and a slight displacement. [35] The DPPy chromophore with two phenyl substituents on the 1,6positions of pyrene can form an excimer with a parallel arranged sandwich geom etry due to the small steric hindrance in its lateral direction (Figure 1b). On the other hand, the TPPy chromophore cannot form such a parallel arranged and closely stacked sandwich geometry, owing to its bulkiness due to the four phenyl sub stituents.…”

Delayed Excimer Fluorescence of Fluoranthene Due to Triplet-Triplet Annihilation: Systematic Study of the Fluorescence from a Weakly Bound Excimer

“…, (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) where k rad E and k rad M are the rate constants for the radiative decay of the excimer and the excited monomer. In practice, an upper integration limit t ∞ ≈ 10/(k S ) min will be virtually equivalent to infinity.…”

“…First, for each discrete time t the corresponding mean radii R E (t) and R M (t) are calculated, (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) with an analogous expression for R M (t). First, for each discrete time t the corresponding mean radii R E (t) and R M (t) are calculated, (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) with an analogous expression for R M (t).…”

“…A more realistic potential energy diagram was introduced by Warshel and Huler in 1974 [9]. A more realistic potential energy diagram was introduced by Warshel and Huler in 1974 [9].…”