Spin-Selective Photoreduction of a Stable Radical within a Covalent Donor-Acceptor-Radical Triad

Article abstract of DOI:10.1021/jacs.7b10458

Controlling spin-spin interactions in multispin molecular assemblies is important for developing new approaches to quantum information processing. In this work, a covalent electron donor-acceptor-radical triad is used to probe spin-selective reduction of

Full text of DOI:10.1021/jacs.7b10458

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Communication
Spin-selective Photoreduction of a Stable Radical
within a Covalent Donor-Acceptor-Radical Triad
Brandon K. Rugg, Brian T Phelan, Noah E. Horwitz, Ryan M. Young,
Matthew D. Krzyaniak, Mark A. Ratner, and Michael R. Wasielewski
J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.7b10458 • Publication Date (Web): 26 Oct 2017
Downloaded from http://pubs.acs.org on October 26, 2017
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Spin-selective Photoreduction of a Stable Radical within a
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Brandon K. Rugg, Brian T. Phelan, Noah E. Horwitz, Ryan M. Young, Matthew D. Krzyaniak, Mark A.
Ratner, and Michael R. Wasielewski*
Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston,
Illinois 60208ꢀ3113, United States.
Supporting Information Placeholder
ABSTRACT: Controlling spinꢀspin interactions in multiꢀspin
molecular assemblies is important for developing new approaches
to quantum information processing. In this work, a covalent elecꢀ
tron donorꢀacceptorꢀradical triad is used to probe spinꢀselective
reduction of the stable radical to its diamagnetic anion. The moleꢀ
cule consists of a perylene electron donor chromophore (D) bound
to a pyromellitimide acceptor (A), which is, in turn, linked to a
•
stable α,γꢀbisdiphenyleneꢀβꢀphenylallyl radical (R ) to produce Dꢀ
•
•
AꢀR . Selective photoexcitation of D within DꢀAꢀR results in
+
•
ꢀ•
•
ultrafast electron transfer to form the D ꢀA ꢀR triradical, where
D ꢀA is a singlet spinꢀcorrelated radical pair (SCRP), in which
both SCRP spins are uncorrelated relative to the R spin. Subseꢀ
quent ultrafast electron transfer within the triradical forms D ꢀAꢀ
R , but its yield is controlled by spin statistics of the uncorrelated
A ꢀR radical pair, where the initial charge separation yields a 3:1
statistical mixture of D ꢀ (A ꢀR ) and D ꢀ (A ꢀR ), and subseꢀ
quent reduction of R only occurs in D ꢀ (A ꢀR ). These findings
inform the design of multiꢀspin systems to transfer spin coherence
between molecules targeting quantum information processing
using the agency of SCRPs.
+•
ꢀ•
•
+•
ꢀ
ꢀ
•
•
+
• 3
ꢀ•
•
+• 1
ꢀ•
•
•
+• 1
ꢀ•
•
Multiꢀspin organic molecules and materials provide new ways
to prepare architectures useful for quantum information proꢀ
1
cessing (QIP) and spintronics. An important requirement for such
that have both the electronic and magnetic properties necessary to
carry out this process is challenging.
systems is the ability to generate wellꢀdefined spin states involvꢀ
ing multiple electron spins. Fast photoꢀinitiated electron transfer
within a covalently linked electron donorꢀacceptor (DꢀA) moleꢀ
cule can result in the formation of a spinꢀcorrelated radical pair
SCRP) with a wellꢀdefined initial singlet spin configuration.
SCRPs in DꢀA systems display coherent spin motion for as long
as ~100 ns, which can provide the basis for the development of
new QIP strategies. Another important requirement for utilizing
SCRPs in QIP applications is developing an understanding of
their interactions with a third electron spin. For example, Salikhov
1
+•
ꢀ•
The initially formed singlet SCRP, (D ꢀA ), generally underꢀ
goes hyperfine couplingꢀinduced intersystem crossing in a few
3
+•
ꢀ•
nanoseconds to produce the triplet SCRP, (D ꢀA ), provided that
the electron spinꢀspin exchange (J) and dipolar interactions (D)
between the two radicals are comparable to, or smaller than, the
electronꢀnuclear hyperfine interactions in the radicals. Application
2
(
3
4
of a magnetic field, B , results in Zeeman splitting of the SCRP
0
triplet sublevels, which at the high fields typical of EPR spectrosꢀ
copy are theꢀ|ꢁꢂꢃ〉,ꢀ|ꢁ 〉, andꢀ|ꢁꢅꢃ〉 eigenstates that are quantized
5
ꢄ
et al. have proposed using a radical ion that is part of a photoꢀ
generated SCRP to oxidize or reduce a third stable radical (R ),
along B , while the |ꢆꢇ state energy remains field invariant (Figure
•
0
6
S3). The magnitude of J decreases exponentially with SCRP
which is first prepared in a coherent spin state using a selective
3
+•
ꢀ•
distance r, while that of D diminishes by 1/r . Thus, if the D ꢀA
+•
ꢀ•
•
+•
ꢀ
π/2 microwave pulse, e.g. D ꢀA ꢀR → D ꢀAꢀR , to move or
distance is short, J and/or D are large, so that the SCRP remains
spinꢀlocked in its initial singlet state.
•
+•
“
teleport” the prepared R spin state to D . Designing molecules
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Figure 2. Energies of states involved in ET processes of 1.
prepared by chemical oxidation with tris(4ꢀbromophenyl)aminium
Figure 1. UVꢀVis spectra of the indicated species in CH Cl .
2
2
ꢀ
•
ꢀ
hexachloroantimonate as well as A in 2H and R in 3 prepared by
+•
ꢀ•
•
Immediately upon formation of D ꢀA ꢀR , throughꢀbond spinꢀ
*
chemical reduction with CoCp 2 and CoCp , respectively. The
+•
2
spin exchange interactions are also established between D and
methods used to determine ε for these species are described in the
•
ꢀ•
•
+•
ꢀ•
R (J ) as well as between A and R (J ). Since the D ꢀA and
1*
14
DR
AR
SI. The energy of D is 2.76 eV, and the free energies of the
various chargeꢀseparated states relative to the ground state of 1
were estimated using the intermolecular donorꢀacceptor distance
(rDA), the redox potentials EOX for the donor and ERED for the
ꢀ
•
•
A ꢀR distances are relatively short, we assume that both J and
JAR are large. Moreover, since the D ꢀR distance is much longer
than that of A ꢀR , J >> JDR, so that J can be neglected. The
sign of JAR determines whether (A ꢀR ) or (A ꢀR ) is the lowest
energy spin configuration of A and R . Also, it is well known
that spinꢀorbitꢀinduced intersystem crossing (SOꢀISC) in organic
diradicals takes place on a relatively slow time scale, typically
DA
+
•
•
ꢀ
•
•
AR
DR
1
ꢀ•
•
3
ꢀ•
•
ꢀ•
•
(a)
-1 ps
1 ps
49 ps
99 ps
100
6
7
ꢀ1 7
+•
ꢀ•
•
~10 ꢀ10 s , thus if D ꢀA ꢀR is formed much faster, the initial
ꢀ
•
•
spin relationship between A and R should be purely statistical,
5 ps
10 ps
25 ps
249 ps
999 ps
1
ꢀ•
•
3
ꢀ•
• 8
i.e. 25% (A ꢀR ) and 75% (A ꢀR ). Assuming that the charge
+•
ꢀ•
•
•
50
recombination reaction: D ꢀA ꢀR → DꢀAꢀR is slower than the
+•
ꢀ•
•
+•
ꢀ
subsequent radical reduction reaction: D ꢀA ꢀR → D ꢀAꢀR , and
1
ꢀ•
•
thus not competitive, the latter reaction requires (A ꢀR ), so that
+
•
ꢀ
only a 25% yield of D ꢀAꢀR is expected. On the other hand, if
0
1,3
ꢀ•
•
(
A ꢀR ) SOꢀISC is faster than the rate of radical reduction,
when J < 0, SOꢀISC of the initial (A ꢀR ) population could
produce (A ꢀR ) resulting in a D ꢀAꢀR yield > 25%, while if J
> 0, SOꢀISC of the initial (A ꢀR ) population to (A ꢀR ) could
3
ꢀ•
•
AR
1
ꢀ•
•
+•
ꢀ
AR
1
ꢀ•
•
3
ꢀ•
•
-50
60
+•
ꢀ
result in a D ꢀAꢀR yield < 25%.
4
50 500 550 600 650 700 750
Research on how RPs formed by statistical encounters are afꢀ
fected by magnetic fields, microwaves, or substrate properties has
thus far been limited to experiments involving intermolecular
radicalꢀradical collisions in viscous solvents, micelles and solids
Wavelength (nm)
(b)
9
•
(
including devices). Here we describe a covalent DꢀAꢀR system
consisting of a perylene (D) electron donor chromophore bound to
a pyromellitimide (A) acceptor, which is, in turn, linked to a staꢀ
3
0
0
•
ble α,γꢀbisdiphenyleneꢀβꢀphenylallyl (R ) radical to produce DꢀAꢀ
•
R . Although similar designs have been used to probe the impact
10
of a third spin on the spin dynamics of SCRPs, to our
knowledge, this is the first study that focuses on a redox reaction
of the SCRP with a covalently bound third radical and probes the
-30
-60
•
influence of spin statistics on this process. We find that the R
τ1 = 9.7
±
0.1 ps
0.4 ps
reduction yield is in fact limited by spin statistics (Φ = 0.23 ±
τ2 = 105.5
±
0
.02), despite the fact that the rate constant for this reduction is
11 ꢀ1
450 500 550 600 650 700 750
Wavelength (nm)
very fast, >10 s . These results establish design principles for
•
DꢀAꢀR molecules that can be used to exploit spin dynamics in
9a,b,11
12
13
organic electronics,
spintronics, and photocatalysis.
Figure 3. fsTA data (λex = 414 nm) of (a) 1H in CH Cl with its
The synthesis and characterization of 1, 1H, and 2 are deꢀ
scribed in the Supporting Information (SI), while their UVꢀvis
absorption spectra in CH Cl are shown in Figure 1. The spectrum
2
2
corresponding decayꢀassociated spectra (b) obtained from globꢀ
al fitting to a sum of exponential decays (see SI). Values and
uncertainties are reported as the average and standard deviation,
respectively, from three independent experiments.
2
2
of 1 is composed of absorption from both D (λ = 446 nm) and
max
•
+•
R (λ
= 494 nm). Also included are the spectra of D in 1H
max
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(a)
(a)
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00
1
*
•
D - A - R
8
0
0
+
•
-
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+
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-
-
20
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00 450 500 550 600 650 700 750
Wavelength (nm)
(
b)
(b)
1
*
•
1
0
0
.00
.75
.50
D - A - R
+
•
-•
•
D - A - R
+
•
-
D - A - R
0.25
.00
0
0
.1
1
10
100
1000 10000
Time (ps)
Figure 5. (a) Basis spectra of the indicated species used to
obtain (b) the population dynamics after photoexcitation of 1
in CH Cl (hollow circles) overlaid with the populations fit to
Figure 4. fsTA data (λex = 414 nm) of (a) 1 in CH Cl with its
2
2
corresponding decayꢀassociated spectra (b) obtained from global
fitting to a sum of exponential decays (see SI). Values and uncerꢀ
tainties are reported as the average and standard deviation, reꢀ
spectively, from three independent experiments.
2
2
the spinꢀselective model (solid lines, same color code).
3*
(
ꢁG = ꢀ0.18 eV), as D formation is energetically unfavorable
from D ꢀAꢀR (ꢁG = 0.15 eV). As no D is observed from
charge recombination of the corresponding state (D ꢀA ꢀRH) in
H, its formation is likely driven by enhanced intersystem crossꢀ
ing (EISC) due to proximity of D ꢀA to R (Figure S9).
+
•
ꢀ
3*
1
*
acceptor, and the energy of D (E ), where ꢀG
e /r (Figures 2 and S2).
= EOX ꢀ ERED
ꢀ
S
DA
+•
ꢀ•
2
15
DA
1
The photoꢀinitiated electron transfer processes of 1H and 1 in
+•
ꢀ•
•
16
A
CH Cl were observed using femtosecond and nanosecond transiꢀ
ent absorption spectroscopy (fsTA and nsTA, see SI for details).
Dyad 1H contains the diamagnetic precursor to R (RH), thus
serving as a donorꢀacceptor reference molecule for 1. Photoexcitaꢀ
tion of 1H (λex = 414 nm) immediately forms DꢀAꢀRH as indiꢀ
cated by the appearance of the intense D absorption at 715 nm,
stimulated emission (SE) at 450ꢀ550 nm, and the ground state
2
2
complete description of the global fitting procedures is given in
the SI.
•
Although the initial photoꢀgenerated RP is spinꢀcorrelated,
the initial interaction between the A and R spins is purely statisꢀ
tical. Thus, there should be two spectrally indistinguishable popuꢀ
lations of the initial photoꢀgenerated SCRP: D ꢀ (A ꢀR ) and D ꢀ
A ꢀR ) in a 3:1 ratio, where only the population in which A and
R are in a singlet spin configuration can result in spinꢀallowed
reduction of R to R . To test whether spin statistics control the
final observed yield of D ꢀAꢀR , the fsTA data set was deconvoꢀ
luted using basis spectra representative of D, D ꢀA ꢀR , and
ꢀ
•
•
1*
1
*
+• 3
ꢀ•
•
+•
1
ꢀ•
•
ꢀ•
1
4
(
bleach (GSB) of D at 400ꢀ450 nm (Figure 3a). Decayꢀassociated
spectral fitting shows that this is followed by fast formation of
•
•
ꢀ
+•
ꢀ•
D ꢀA ꢀRH in τ = 9.7 ± 0.1 ps and subsequent charge recombiꢀ
CS1
•+
ꢀ
nation to ground state (CR1) in τCR1 = 105.5 ± 0.4 ps (Figure 3b).
1*
+•
ꢀ•
•
1
*
•
Similar behavior is observed in 1 (Figure 4a) where DꢀAꢀR
+•
ꢀ
D ꢀAꢀR scaled to the measured extinction coefficients of the
component species (Figure 5a) making no assumptions about the
+•
ꢀ•
•
deactivates in τD = 8.6 ± 0.3 ps to form D ꢀA ꢀR along with
further charge separation to form D ꢀAꢀR as seen by the persisꢀ
tence of the D absorption at 550 nm, increased absorption at 610
nm resulting from R , and the GSB of R at 490 nm. Charge reꢀ
combination of D ꢀ A ꢀR occurs in τ
b), while D ꢀAꢀR decays in τ
0% yield of D is observed after recombination of D ꢀAꢀR ,
which most likely forms from charge recombination of D ꢀA ꢀR
+•
ꢀ
+•
ꢀ•
•
fraction of the D ꢀA ꢀR population that would react further to
+
•
+•
ꢀ
1*
•
+•
ꢀ•
•
produce D ꢀAꢀR . The populations of DꢀAꢀR , D ꢀA ꢀR and
ꢀ
•
+•
ꢀ
D ꢀAꢀR that result from this analysis, normalized to unity at t ,
are shown in Figure 5b. It is immediately clear that k >> k
for 1; indeed, at t = 30 ps, the apparent population of D ꢀAꢀR has
plateaued, while there is still more than twice that amount of D ꢀ
0
+•
ꢀ•
•
= 95.1 ± 0.3 ps (Figure
= 85.7 ± 0.7 ns (Figure S9). A
CR1
CS2
+•
CR1
+•
ꢀ
4
1
ꢀ
CR2
3
*
+•
ꢀ
+•
+
•
ꢀ•
•
ꢀ•
•
A ꢀR remaining. In addition, since k
> kCS1, i.e. the charge
CS2
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separation kinetics of the second step are inverted relative to those
Angerhofer, A.; Wasielewski, M. R.; Svec, W. A.; Norris, J. R. J. Phys.
Chem. 1995, 99, 4324.
4) (a) Harneit, W. Phys. Rev. A 2002, 65, 032322; (b) Bogani, L.;
Wernsdorfer, W. Nat Mater 2008, 7, 179; (c) Kobr, L.; Gardner, D. M.;
Smeigh, A. L.; Dyar, S. M.; Karlen, S. D.; Carmieli, R.; Wasielewski, M.
R. J. Am. Chem. Soc. 2012, 134, 12430; (d) Krzyaniak, M. D.; Kobr, L.;
Rugg, B. K.; Phelan, B. T.; Margulies, E. A.; Nelson, J. N.; Young, R. M.;
Wasielewski, M. R. J. Mater. Chem. C 2015, 3, 7962.
+• 1
ꢀ•
•
1
2
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1
1
1
1
1
1
1
1
1
1
2
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of the first step, the population of D ꢀ (A ꢀR ) present at any
given time is very small, so that the fsTA spectrum showing the
initial chargeꢀseparated state is completely dominated by the popꢀ
(
+• 3
ꢀ•
•
ulation of D ꢀ (A ꢀR ). The population data were fit to a kinetic
+
• 3
ꢀ•
•
+•
model in which the separate populations of D ꢀ (A ꢀR ) and D ꢀ
1
ꢀ•
•
(
A ꢀR ) were allowed to vary (see SI). The solid lines in Figure
b are the results of this fit and show that the D ꢀAꢀR yield is
+•
ꢀ
5
(5) (a) Salikhov, K. M.; Golbeck, J. H.; Stehlik, D. Appl. Magn. Res. 2007,
3
1, 237; (b) Kandrashkin, Y. E.; Salikhov, K. M. Appl. Magn. Res. 2010,
37, 549.
6) (a) Closs, G. L.; Forbes, M. D. E.; Norris, J. R. J. Phys. Chem. 1987,
1, 3592; (b) Buckley, C. D.; Hunter, D. A.; Hore, P. J.; McLauchlan, K.
0
.23 ± 0.02, in close agreement with the 0.25 yield predicted from
the spin statistics of two uncorrelated spins.
(
9
•
In summary, the reversible reduction of a stable radical R by a
•
0
1
2
3
4
5
6
7
8
9
0
1
2
3
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7
8
9
0
1
2
3
4
5
6
7
8
9
0
covalently attached singlet SCRP was observed. The yield of R
reduction is limited by the statistical population of (A ꢀR ),
consistent with the reactions D ꢀA ꢀR → DꢀAꢀR and D ꢀA ꢀR
A. Chem. Phys. Lett. 1987, 135, 307; (c) Till, U.; Hore, P. J. Mol. Phys.
1997, 90, 289.
(7) (a) Abe, M. Chem. Rev. 2013, 113, 7011; (b) Mizuno, T.; Abe, M.;
Ikeda, N. Aust. J. Chem. 2015, 68, 1700.
1,3
ꢀ•
•
+•
ꢀ•
•
•
+•
ꢀ•
•
+•
ꢀ
1,3
ꢀ•
•
→ D ꢀAꢀR being much faster than (A ꢀR ) SOꢀISC. In addiꢀ
tion, no evidence is found for spin state mixing, most likely beꢀ
cause JDA and JAR are sufficiently large to preclude spin dynamics
occurring on the ultrafast time scale of the electron transfer reacꢀ
tions observed in this system. The ability to carry out spinꢀ
selective redox reactions between a SCRP and a stable third radiꢀ
cal makes it possible to explore spin coherence phenomena in
(8) (a) Buxton, G. V.; Greenstock, C. L.; Helman, W. P.; Ross, A. B. J.
Phys. Chem. Ref. Data 1988, 17, 513; (b) Ichino, T.; Fessenden, R. W. J.
Phys. Chem. A 2007, 111, 2527.
(9) (a) Xu, Z.; Hu, B. Adv. Funct. Mater. 2008, 18, 2611; (b) Cho, N.;
Schlenker, C. W.; Knesting, K. M.; Koelsch, P.; Yip, H.ꢀL.; Ginger, D. S.;
Jen, A. K. Y. Adv. Ener. Mater. 2014, 4, 1301857; (c) Herring, T. W.;
Lee, S. Y.; McCamey, D. R.; Taylor, P. C.; Lips, K.; Hu, J.; Zhu, F.;
Madan, A.; Boehme, C. Phys. Rev. B 2009, 79, 195205; (d) Cozens, F. L.;
Scaiano, J. C. J. Am. Chem. Soc. 1993, 115, 5204; (e) Margulis, L. A.;
Khudyakov, I. V.; Kuzmin, V. A. Chem. Phys. Lett. 1986, 124, 483; (f)
Borovkov, V. I.; Ivanishko, I. S.; Bagryansky, V. A.; Molin, Y. N. J.
Phys. Chem. A 2013, 117, 1692; (g) Forbes, M. D. E.; Jarocha, L. E.; Sim,
S.; Tarasov, V. F. Adv. Phys. Org. Chem. 2013, 47, 1; (h) Tarasov, V. F.;
Jarocha, L. E.; Avdievich, N. I.; Forbes, M. D. E. Photochem. Photobiol.
Sci. 2014, 13, 439; (i) Tarasov, V. F.; Jarocha, L. E.; Forbes, M. D. E.
Photochem. Photobiol. Sci. 2014, 13, 454.
+•
ꢀ
systems having longꢀlived D ꢀAꢀR states as well as perform
novel QIP experiments using pulseꢀEPR spectroscopy.
ASSOCIATED CONTENT
Supporting Information
Supporting Information is available free of charge on the ACS
Publications website at DOI: 10.1021/xxxx.xxxxxx. Experimental
details and characterization for new compounds as well as NMR
spectra, electrochemical measurements, additional transient abꢀ
sorption data, kinetic modeling, and DFT calculations.
(10) (a) Corvaja, C.; Maggini, M.; Ruzzi, M.; Scorrano, G.; Toffoletti, A.
Appl. Magn. Res. 1997, 12, 477; (b) Horwitz, N. E.; Phelan, B. T.; Nelson,
J. N.; Krzyaniak, M. D.; Wasielewski, M. R. J. Phys. Chem. A 2016, 120,
2
841; (c) Weiss, E. A.; Chernick, E. T.; Wasielewski, M. R. J. Am. Chem.
Soc. 2004, 126, 2326; (d) Chernick, E. T.; Mi, Q.; Kelley, R. F.; Weiss, E.
A.; Jones, B. A.; Marks, T. J.; Ratner, M. A.; Wasielewski, M. R. J. Am.
Chem. Soc. 2006, 128, 4356; (e) Ishii, K.; Hirose, Y.; Kobayashi, N. J.
Phys. Chem. A 1999, 103, 1986.
(11) (a) Wohlgenannt, M.; Jiang, X. M.; Vardeny, Z. V. Physica B:
Condensed Matter 2003, 338, 318; (b) Beljonne, D.; Ye, A.; Shuai, Z.;
Brédas, J. L. Adv. Funct. Mater. 2004, 14, 684; (c) Sun, Y.; Giebink, N.
C.; Kanno, H.; Ma, B.; Thompson, M. E.; Forrest, S. R. Nature 2006, 440,
AUTHOR INFORMATION
Corresponding Author
mꢀwasielewski@northwestern.edu
Notes
The authors declare no competing financial interests.
9
08; (d) Kersten, S. P.; Schellekens, A. J.; Koopmans, B.; Bobbert, P. A.
Phys. Rev. Lett. 2011, 106, 197402; (e) Koh, S. E.; Delley, B.;
Medvedeva, J. E.; Facchetti, A.; Freeman, A. J.; Marks, T. J.; Ratner, M.
A. J. Phys. Chem. B 2006, 110, 24361; (f) Rao, A.; Chow, P. C.; Gelinas,
S.; Schlenker, C. W.; Li, C. Z.; Yip, H. L.; Jen, A. K.; Ginger, D. S.;
Friend, R. H. Nature 2013, 500, 435.
ACKNOWLEDGMENT
T his work was supported by the National Science Foundation
under grant no. CHEꢀ1565925.
(12) (a) Ratera, I.; Veciana, J. Chem. Soc. Rev. 2012, 41, 303; (b) Souto,
REFERENCES
M.; Yuan, L.; Morales, D. C.; Jiang, L.; Ratera, I.; Nijhuis, C. A.;
Veciana, J. J. Am. Chem. Soc. 2017, 139, 4262; (c) Morita, Y.; Nishida,
S.; Murata, T.; Moriguchi, M.; Ueda, A.; Satoh, M.; Arifuku, K.; Sato, K.;
Takui, T. Nat Mater 2011, 10, 947; (d) Nishida, S.; Morita, Y.; Fukui, K.;
Sato, K.; Shiomi, D.; Takui, T.; Nakasuji, K. Angew. Chem., Int. Ed. 2005,
44, 7277.
(1) (a)Boehme, C.; Lupton, J. M. Nature Nanotech. 2013, 8, 612; (b)
Moodera, J. S.; Koopmans, B.; Oppeneer, P. M. MRS Bulletin 2014, 39,
5
78; (c) Naber, W. J. M.; Faez, S.; van der Wiel, W. G. J. Phys. D: Appl.
Phys. 2007, 40, R205; (d) Rocha, A. R.; GarciaꢀSuarez, V. M.; Bailey, S.
W.; Lambert, C. J.; Ferrer, J.; Sanvito, S. Nat Mater 2005, 4, 335; (e) Sun,
D.; Ehrenfreund, E.; Vardeny, Z. V. Chem. Commun. 2014, 50, 1781.
(
(
13) (a)Buchachenko, A. L.; Berdinsky, V. L. Chem. Rev. 2002, 102, 603;
b) Griesbeck, A. G. Synlett 2003, 2003, 0451; (c) Hammarström, L. Acc.
(2) (a)Hasharoni, K.; Levanon, H.; Greenfield, S. R.; Gosztola, D. J.;
Chem. Res. 2015, 48, 840.
14) Veldkamp, B. S.; Han, W.ꢀS.; Dyar, S. M.; Eaton, S. W.; Ratner, M.
A.; Wasielewski, M. R. Energy Environ. Sci. 2013, 6, 1917.
Svec, W. A.; Wasielewski, M. R. J. Am. Chem. Soc. 1995, 117, 8055; (b)
Shaakov, S.; Galili, T.; Stavitski, E.; Levanon, H.; Lukas, A.;
Wasielewski, M. R. J. Am. Chem. Soc. 2003, 125, 6563; (c) Carbonera,
D.; Di Valentin, M.; Corvaja, C.; Agostini, G.; Giacometti, G.; Liddell, P.
A.; Kuciauskas, D.; Moore, A. L.; Moore, T. A.; Gust, D. J. Am. Chem.
Soc. 1998, 120, 4398; (d) Colvin, M. T.; Ricks, A. B.; Scott, A. M.;
Smeigh, A. L.; Carmieli, R.; Miura, T.; Wasielewski, M. R. J. Am. Chem.
Soc. 2011, 133, 1240.
(
(15) Weller, A. Z. Phys. Chem. 1982, 133, 93.
(16) Colvin, M. T.; Carmieli, R.; Miura, T.; Richert, S.; Gardner, D. M.;
Smeigh, A. L.; Dyar, S. M.; Conron, S. M.; Ratner, M. A.; Wasielewski,
M. R. J. Phys. Chem. A 2013, 117, 5314.
(3) (a) Hoff, A. J.; Gast, P.; Dzuba, S. A.; Timmel, C. R.; Fursman, C. E.;
Hore, P. J. Spectrochim. Acta, Part A 1998, 54A, 2283; (b) Kothe, G.;
Weber, S.; Ohmes, E.; Thurnauer, M. C.; Norris, J. R. J. Am. Chem. Soc.
1
994, 116, 7729; (c) Laukenmann, K.; Weber, S.; Kothe, G.; Oesterle, C.;
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