10.1021/ic034559m.s001
Lianhe Yu
Lianhe
Yu
Kannan Muthukumaran
Kannan
Muthukumaran
Igor V. Sazanovich
Igor V.
Sazanovich
Christine Kirmaier
Christine
Kirmaier
Eve Hindin
Eve
Hindin
James R. Diers
James R.
Diers
Paul D. Boyle
Paul D.
Boyle
David F. Bocian
David F.
Bocian
Dewey Holten
Dewey
Holten
Jonathan S. Lindsey
Jonathan S.
Lindsey
Excited-State Energy-Transfer Dynamics in Self-Assembled Triads
Composed of Two Porphyrins and an Intervening Bis(dipyrrinato)metal
Complex
American Chemical Society
2003
2 Zn
zinc porphyrins
THF
zinc porphyrin
oxidation
DDQ
bi
InCl 3 catalysis
2 Pd unit
2 Zn triad
Free base dipyrrins
energy transfer
divalent metal ions
complex
room temperature
preparation exploits
2003-09-17 00:00:00
Dataset
https://acs.figshare.com/articles/dataset/Excited-State_Energy-Transfer_Dynamics_in_Self-Assembled_Triads_Composed_of_Two_Porphyrins_and_an_Intervening_Bis_dipyrrinato_metal_Complex/3582297
The synthesis and characterization of various triads composed of a linear array of two zinc porphyrins joined via
an intervening bis(dipyrrinato)metal(II) complex are reported. The preparation exploits the facile complexation of
dipyrrins with divalent metal ions to give bis(dipyrrinato)metal(II) complexes [abbreviated (dp)<sub>2</sub>M]. Copper(II) and
palladium(II) chelates of dipyrrins (available by oxidation of dipyrromethanes) were prepared in 50−80% yield. A
one-flask synthesis of bis(dipyrrinato)zinc(II) complexes was developed by oxidation of a dipyrromethane with DDQ
or <i>p</i>-chloranil in the presence of Zn(OAc)<sub>2</sub>·2H<sub>2</sub>O in THF (∼80% yield). Three routes were developed for preparing
porphyrin-dipyrrins: (1) Suzuki coupling of a boronate-substituted zinc porphyrin (ZnP) and bis[5-(4-iodophenyl)dipyrrinato]Pd(II) to give the (ZnP-dp)<sub>2</sub>Pd triad (50% yield), followed by selective demetalation of the (dp)<sub>2</sub>Pd unit
by treatment with 1,4-dithiothreitol under neutral conditions (71% yield); (2) oxidation of a porphyrin-dipyrromethane
with <i>p</i>-chloranil in the presence of Zn(OAc)<sub>2</sub>·2H<sub>2</sub>O followed by chromatography on silica gel (71% yield); and (3)
condensation of a dipyrrin-dipyrromethane and a dipyrromethane-dicarbinol under InCl<sub>3</sub> catalysis followed by oxidation
with DDQ (10−16% yield). Four triads of form (ZnP-dp)<sub>2</sub>Zn were prepared in 83−97% yield by treatment of a
porphyrin-dipyrrin with Zn(OAc)<sub>2</sub>·2H<sub>2</sub>O at room temperature. Free base dipyrrins typically absorb at 430−440 nm,
while the bis(dipyrrinato)metal complexes absorb at 460−490 nm. The fluorescence spectra/yields and excited-state lifetimes of the (ZnP-dp)<sub>2</sub>Zn triad in toluene show (1) efficient energy transfer from the bis(dipyrrinato)zinc(II)
chromophore to the zinc porphyrins (98.5% yield), and (2) little or no quenching of the resulting excited zinc
porphyrin relative to the isolated chromophore. Taken together, these results indicate that bis(dipyrrinato)zinc(II)
complexes can serve as self-assembling linkers that further function as secondary light-collection elements in
porphyrin-based light-harvesting arrays.