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Title: Excited Charge Separation in a π-Interacting Phenothiazine–Zinc Porphyrin–Fullerene Donor–Acceptor Conjugate
A zinc phthalocyanine-pyrroloperylenediimide dyad connected through a nitrogen heteroatom (PDI-N-ZnPc) has been newly synthesized and characterized. Solvent polarity-dependent singlet-singlet energy transfer and electron transfer quenching were envisioned from absorption and steady-state fluorescence studies. Electrochemical and spectroelectrochemical studies enabled the assessment of the redox potential of the donor and acceptor entities, as well as the spectral characterization of the one-electron oxidation and reduction products. DFT studies were performed to investigate the geometry and electronic structure, as well as the role of N-connectivity in determining the relative orientation of the entities. Further, time-dependent DFT studies helped establish the different excited states responsible for promoting charge separation. An energy diagram was subsequently established to visualize different photo-physical events. Finally, femtosecond transient absorption spectral studies were performed in both nonpolar and polar solvents to observe energy and electron transfer events. The kinetic data were subsequently analyzed using global and target analyses. The persistence of the charge-separated state in the present dyad, compared with earlier reported ZnPc-PDI dyads featuring carbon-carbon connectivity, was the primary outcome of the present study, highlighting the role of heteroatom linkage in regulating electron transfer dynamics in donor-acceptor conjugates.  more » « less
Award ID(s):
2345836
PAR ID:
10673200
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  
Editor(s):
Shea, JE
Publisher / Repository:
ACS
Date Published:
Journal Name:
The Journal of Physical Chemistry A
Volume:
128
Issue:
21
ISSN:
1089-5639
Page Range / eLocation ID:
4233 to 4241
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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