The nature of the lowest excited state of aryl-pyrene derivatives results in the competition between the stabilization of a planar geometry by Mesomeric Intramolecular Charge Transfer (MICT) and the stabilisation in a Twisted Intramolecular Charge Transfer (TICT) state by a perpendicular orientation of the pyrene and pyridyl moiety. By combining the photoluminescence, TCSPC and transient absorption results, we deduced that following the excitation of Pyr2Bpy at 380 nm a MICT state is formed within approx. 1-2 ps by a charge delocalisation from the pyrene to the bipyridine moiety. After this initial step, the S1 state of Pyr2Bpy decays mainly by emission (em = 78 %, in THF) and with a relatively short lifetime of 1.4 ns, in good agreement with the strong emission oscillator strength expected from a MICT state . This description is in good agreement with results from steady state emission measurements of Pyr2Bpy in different solvent reported by Ortí and co-workers , and with the result of quantum calculations showing the planarization of the molecule in the S1 excited state due to the extension of the -conjugation over the Pyr2BPY molecule .