TY - JOUR
T1 - Guest-induced modulation of the energy transfer process in porphyrin-based artificial light harvesting dendrimers
AU - Yim, Dajeong
AU - Sung, Jooyoung
AU - Kim, Serom
AU - Oh, Juwon
AU - Yoon, Hongsik
AU - Sung, Young Mo
AU - Kim, Dongho
AU - Jang, Woo Dong
N1 - Publisher Copyright:
© 2016 American Chemical Society.
PY - 2017/1/18
Y1 - 2017/1/18
N2 - A series of dendritic multiporphyrin arrays (PZnTz-nPFB; n =2, 4, 8) comprising a triazole-bearing focal zinc porphyrin (PZn) with a different number of freebase porphyrin (PFB) wings has been synthesized, and their photoinduced energy transfer process has been evaluated. UV/vis absorption, emission, and time-resolved fluorescence measurements indicated that efficient excitation energy transfer takes place from the focal PZn to PFB wings in PZnTz-nPFB's. The triazole-bearing PZn effectively formed host-guest complexes with anionic species by means of axial coordination with the aid of multiple C-H hydrogen bonds. By addition of various anionic guests to PZnTz and PZnTz-nPFB's, strong bathochromic shifts of PZn absorption were observed, indicating the HOMO-LUMO gap (ΔEHOMO-LUMO) of PZn decreased by anion binding. Time-resolved fluorescence measurements revealed that the fluorescence emission predominantly takes place from PZn in PZnTz-nPFB's after the addition of CN-. This change was reversible because a treatment with a silver strip to remove CN fully recovered the original energy transfer process from the focal PZn to PFB wings.
AB - A series of dendritic multiporphyrin arrays (PZnTz-nPFB; n =2, 4, 8) comprising a triazole-bearing focal zinc porphyrin (PZn) with a different number of freebase porphyrin (PFB) wings has been synthesized, and their photoinduced energy transfer process has been evaluated. UV/vis absorption, emission, and time-resolved fluorescence measurements indicated that efficient excitation energy transfer takes place from the focal PZn to PFB wings in PZnTz-nPFB's. The triazole-bearing PZn effectively formed host-guest complexes with anionic species by means of axial coordination with the aid of multiple C-H hydrogen bonds. By addition of various anionic guests to PZnTz and PZnTz-nPFB's, strong bathochromic shifts of PZn absorption were observed, indicating the HOMO-LUMO gap (ΔEHOMO-LUMO) of PZn decreased by anion binding. Time-resolved fluorescence measurements revealed that the fluorescence emission predominantly takes place from PZn in PZnTz-nPFB's after the addition of CN-. This change was reversible because a treatment with a silver strip to remove CN fully recovered the original energy transfer process from the focal PZn to PFB wings.
UR - http://www.scopus.com/inward/record.url?scp=85019134730&partnerID=8YFLogxK
U2 - 10.1021/jacs.6b11804
DO - 10.1021/jacs.6b11804
M3 - Article
C2 - 27977172
AN - SCOPUS:85019134730
SN - 0002-7863
VL - 139
SP - 993
EP - 1002
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 2
ER -