000216629 001__ 216629
000216629 005__ 20180317092952.0
000216629 0247_ $$2doi$$a10.1021/acs.jpclett.5b02146
000216629 022__ $$a1948-7185
000216629 02470 $$2ISI$$a000365460700005
000216629 037__ $$aARTICLE
000216629 245__ $$aLigand-Centred Fluorescence and Electronic Relaxation Cascade at Vibrational Time Scales in Transition-Metal Complexes
000216629 260__ $$aWashington$$bAmer Chemical Soc$$c2015
000216629 269__ $$a2015
000216629 300__ $$a6
000216629 336__ $$aJournal Articles
000216629 520__ $$aUsing femtosecond-resolved photoluminescence up-conversion, we report the observation of the fluorescence of the high-lying ligand-centered (LC) electronic state upon 266 nm excitation of an iridium complex, Ir(ppy)(3), with a lifetime of 70 +/- 10 fs. It is accompanied by a simultaneous emission of all lower-lying electronic states, except the lowest triplet metal-to-ligand charge-transfer ((MLCT)-M-3) state that shows a rise on the same time scale. Thus, we observe the departure, the intermediate steps, and the arrival of the relaxation cascade spanning similar to 1.6 eV from the (LC)-L-1 state to the lowest 3MLCT state, which then yields the long-lived luminescence of the molecule. This represents the first measurement of the total relaxation time over an entire cascade of electronic states in a polyatomic molecule. We find that the relaxation cascade proceeds in <= 10 fs, which is faster than some of the highest-frequency modes of the system. We invoke the participation of the latter modes in conical intersections and their overdamping to low-frequency intramolecular modes. On the basis of literature, we also conclude that this behavior is not specific to transition-metal complexes but also applies to organic molecules.
000216629 700__ $$0244413$$aMessina, Fabrizio$$g207175$$uEcole Polytech Fed Lausanne, ISIC, FSB, LSU, CH-1015 Lausanne, Switzerland
000216629 700__ $$0246573$$aPomarico, Enrico$$g229734$$uEcole Polytech Fed Lausanne, ISIC, FSB, LSU, CH-1015 Lausanne, Switzerland
000216629 700__ $$0246247$$aSilatani, Mahsa$$g218311$$uEcole Polytech Fed Lausanne, ISIC, FSB, LSU, CH-1015 Lausanne, Switzerland
000216629 700__ $$aBaranoff, Etienne
000216629 700__ $$0240045$$aChergui, Majed$$g122830$$uEcole Polytech Fed Lausanne, ISIC, FSB, LSU, CH-1015 Lausanne, Switzerland
000216629 773__ $$j6$$k22$$q4475-4480$$tJournal Of Physical Chemistry Letters
000216629 909CO $$ooai:infoscience.tind.io:216629$$particle$$pSB
000216629 909C0 $$0252026$$pLSU$$xU10862
000216629 917Z8 $$x122830
000216629 937__ $$aEPFL-ARTICLE-216629
000216629 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000216629 980__ $$aARTICLE