Sensitizing the Sensitizer: The Synthesis and Photophysical Study of Bodipy-Pt(II)(diimine)(dithiolate) Conjugates
Φόρτωση...
Ημερομηνία
Συγγραφείς
Lazarides, T.
McCormick, T. M.
Wilson, K. C.
Lee, S.
McCamant, D. W.
Eisenberg, R.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
American Chemical Society
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
J Am Chem Soc
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The dyads 3, 4, and 6, combining the Bodipy chromophore with a Pt(bpy)(bdt) (bpy = 2,2'-bipyridine, bdt = 1,2-benzenedithiolate, 3 and 6) or a Pt(bpy)(mnt) (mnt = maleonitriledithiolate, 4) moiety, have been synthesized and studied by UV-vis steady-state absorption, transient absorption, and emission spectroscopies and cyclic voltammetry. Comparison of the absorption spectra and cyclic voltammograms of dyads 3, 4, and 6 and those of their model compounds 1a, 2, 5, and 7 shows that the spectroscopic and electrochemical properties of the dyads are essentially the sum of their constituent chromophores, indicating negligible interaction of the constituent chromophores in the ground state. However, emission studies on 3 and 6 show a complete absence of both Bodipy-based fluorescence and the characteristic luminescence of the Pt(bpy)(bdt) unit. Dyad 4 shows a weak Pt(mnt)-based emission. Transient absorption studies show that excitation of the dyads into the Bodipy-based (1)pi pi* excited state is followed by singlet energy transfer (SEnT) to the Pt(dithiolate)-based (MML)-M-1'CT (mixed metal-ligand to ligand charge transfer) excited state (tau(3)(SEnT) = 0.6 ps, tau(4)(SEnT) = 0.5 ps, and tau(6)(SEnT) = 1.6 ps), which undergoes rapid intersystem crossing to the (MMLL)-M-3'CT state due to the heavy Pt(II) ion. The (MMLL)-M-3'CT state is then depopulated by triplet energy transfer (TEnT) to the low-lying Bodipy-based 3 pi pi* excited state (tau(3)(TEnT) = 8.2 ps, tau(4)(TEnT) = 5 ps, and tau(6)(TEnT) = 160 ps). The transition assignments are supported by TD-DFT calculations. Both energy-transfer processes are shown to proceed via a Dexter electron exchange mechanism. The much longer time constants for dyad 6 relative to 3 are attributed to the significantly poorer coupling and resonance of charge-separated species that are intermediates in the electron exchange process.
Περιγραφή
Λέξεις-κλειδιά
diimine-dithiolate complexes, electron-transfer, excited-state, spectroscopic properties, photoinduced electron, platinum complexes, solar-cells, bodipy dyes, fluorophores, derivatives
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000286544900030
http://pubs.acs.org/doi/pdfplus/10.1021/ja1070366
http://pubs.acs.org/doi/pdfplus/10.1021/ja1070366
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας