Abstract
We report the synthesis and photophysical characterization of isomeric donor-acceptor1-acceptor2 (D-A1-A2) triads each comprising a perylene donor (D) connected by a xylene bridge to a naphthalene-1,8-dicarboximide primary acceptor (NMI, A1) that is, in turn, covalently linked to a naphthalene-1,4:5,8-bis(dicarboximide) secondary acceptor (NDI, A2) through a benzene ring at its ortho, meta or para positions (Per-Xy-NMI-x-NDI). Selective photoexcitation of Per produces both Per+• and NDI‒• simultaneously with time constants of ∼50 ps in benzonitrile and ∼80 ps in toluene with a >98% yield. This is much faster than expected for single-step electron transfer from 1*Per to NDI and is consistent with a two-step mechanism, 1*Per-Xy-NMI-x-NDI → Per+•-Xy-NMI‒•-x-NDI → Per+•-Xy-NMI-x-NDI‒•, in which the second step is much faster than the first step. In addition, preserving long-lived charge separation in these systems is found to depend on inhibiting charge recombination by a triplet radical ion pair recombination pathway.
| Original language | English |
|---|---|
| Pages (from-to) | 4925-4935 |
| Number of pages | 11 |
| Journal | Tetrahedron |
| Volume | 73 |
| Issue number | 33 |
| DOIs | |
| Publication status | Published - Aug 17 2017 |
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Keywords
- Donor-acceptor
- Photochemistry
- Radical pairs
- Transient absorption spectroscopy
ASJC Scopus subject areas
- Biochemistry
- Drug Discovery
- Organic Chemistry
Cite this
Photoinitiated long-lived charge separation with near-unity quantum yield in donor-acceptor1-acceptor2 systems for artificial photosynthesis. / Han, Won Sik; Veldkamp, Brad S.; Dyar, Scott M.; Eaton, Samuel W.; Wasielewski, Michael R.
In: Tetrahedron, Vol. 73, No. 33, 17.08.2017, p. 4925-4935.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Photoinitiated long-lived charge separation with near-unity quantum yield in donor-acceptor1-acceptor2 systems for artificial photosynthesis
AU - Han, Won Sik
AU - Veldkamp, Brad S.
AU - Dyar, Scott M.
AU - Eaton, Samuel W.
AU - Wasielewski, Michael R
PY - 2017/8/17
Y1 - 2017/8/17
N2 - We report the synthesis and photophysical characterization of isomeric donor-acceptor1-acceptor2 (D-A1-A2) triads each comprising a perylene donor (D) connected by a xylene bridge to a naphthalene-1,8-dicarboximide primary acceptor (NMI, A1) that is, in turn, covalently linked to a naphthalene-1,4:5,8-bis(dicarboximide) secondary acceptor (NDI, A2) through a benzene ring at its ortho, meta or para positions (Per-Xy-NMI-x-NDI). Selective photoexcitation of Per produces both Per+• and NDI‒• simultaneously with time constants of ∼50 ps in benzonitrile and ∼80 ps in toluene with a >98% yield. This is much faster than expected for single-step electron transfer from 1*Per to NDI and is consistent with a two-step mechanism, 1*Per-Xy-NMI-x-NDI → Per+•-Xy-NMI‒•-x-NDI → Per+•-Xy-NMI-x-NDI‒•, in which the second step is much faster than the first step. In addition, preserving long-lived charge separation in these systems is found to depend on inhibiting charge recombination by a triplet radical ion pair recombination pathway.
AB - We report the synthesis and photophysical characterization of isomeric donor-acceptor1-acceptor2 (D-A1-A2) triads each comprising a perylene donor (D) connected by a xylene bridge to a naphthalene-1,8-dicarboximide primary acceptor (NMI, A1) that is, in turn, covalently linked to a naphthalene-1,4:5,8-bis(dicarboximide) secondary acceptor (NDI, A2) through a benzene ring at its ortho, meta or para positions (Per-Xy-NMI-x-NDI). Selective photoexcitation of Per produces both Per+• and NDI‒• simultaneously with time constants of ∼50 ps in benzonitrile and ∼80 ps in toluene with a >98% yield. This is much faster than expected for single-step electron transfer from 1*Per to NDI and is consistent with a two-step mechanism, 1*Per-Xy-NMI-x-NDI → Per+•-Xy-NMI‒•-x-NDI → Per+•-Xy-NMI-x-NDI‒•, in which the second step is much faster than the first step. In addition, preserving long-lived charge separation in these systems is found to depend on inhibiting charge recombination by a triplet radical ion pair recombination pathway.
KW - Donor-acceptor
KW - Photochemistry
KW - Radical pairs
KW - Transient absorption spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85020876140&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85020876140&partnerID=8YFLogxK
U2 - 10.1016/j.tet.2017.06.021
DO - 10.1016/j.tet.2017.06.021
M3 - Article
AN - SCOPUS:85020876140
VL - 73
SP - 4925
EP - 4935
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 33
ER -