S1

Supporting Information for:

Photoinduced Electron Transfer from a Tetrathiafulvalene-Calix[4]pyrrole to a Porphyrin Carboxylate within a Su-pramolecular Ensemble

Christina M. Davis,† Yuki Kawashima,‡ Kei Ohkubo,‡ Jong Min Lim,§ Dongho Kim,*,§ Shunichi Fukuzumi,*,‡ and Jonathan L. Sessler*,†

†Department of Chemistry, The University of Texas at Austin, 105 E. 24th Street-Stop A5300, Austin, Texas 78712-1225, United States ‡ Department of Material and Life Science, Graduate School of Engineering, Osaka University, and ALCA, Japan Science and Technology (JST), Suita, Osaka 565-0871, Japan § Department of Chemistry, Yonsei University, Seoul 120-750, Korea

Table of Contents:

Absorption spectra (p. S2) NMR spectra (p. S3)

Density functional theory calculations (p. S3)

Fluorescence spectra (p. S4)

Phosphorescence spectra (p. S4)

Femtosecond transient absorption spectra (p. S5)

Nanosecond transient absorption spectra (p. S6)

Absorbance titration (p. S8)

Electron transfer rate analysis (p. S9)

Eyring plot (p. S10)

Electron spin resonance (p. S10) Supporting References (p. S11)

S2

1.2

1.0

0.8

0.6

0.4

0.2

0.0Norm

aliz

ed A

bsorb

ance (

a.u

.)700600500400300

Wavelength (nm)

1

2

3

Figure S1. Absorption spectra for 1 (black solid), 2 (purple solid), and 3 (purple dashed) as recorded in PhCN

at 298 K.

2.0

1.5

1.0

0.5

0.0

(!-1-1

)-1

200x10-6150100500

[1]-![2]0, M

Figure S2. Linear plot used to determine binding constant (Ka) corresponding to the interaction of 1 with 2.

This plot is based on the observed changes in absorption as detailed in the text. The slope (Ka) is 11,000 ± 240

with an R2 value of 0.99484. (Note: A∞ was set to 2.45 × 10–2; see main text for definitions.)

S3

Figure S3. 1H NMR spectra for (a) tetraethylammonium porphyrin carboxylate 2 (2.5 mM), (b) 1:1 mixture

of 1 and 2, each at 2.5 mM, (c) calix[4]pyrrole 1 (2.5 mM). All spectra were recorded at 298 K in deuterated

chloroform.

Figure S4. The HOMO (left) and LUMO (right) for the optimized supramolecular ensemble formed upon mixing 1

and 2 (complex 4) as calculated by density functionally theory at the B3LYP/6-31G(d) level.

S4

Figure S5. (a) Fluorescence spectrum for 2 (15 mM) in PhCN at 298 K; excitation wavelength: 510 nm. (b) Fluo-

rescence decay profiles of the singlet-excited state of 2 (12*) observed upon excitation at 485 nm in the absence

(black) and the presence of 1 (0.5 mM) (red) in deoxygenated PhCN containing 2 (0.3 mM).

3.4x106

3.2

3.0

2.8

2.6

2.4

2.2

2.0

Inte

nsity (

a.u

.)

840830820810800790

Wavelength (nm)

813 nm

Figure S6. Phosphorescence spectrum of 2 recorded in a solution of 2-methyltetrahydrofuran and ethyl iodide

(1:1), which was then used to form transparent glass upon cooling to T = 77 K where the measurement was

made via excitation at 435 nm.

S5

Figure S7. Femtosecond transient absorption spectra of 12* recorded after irradiation of 2 (0.1 mM) at 400

nm in deoxygenated PhCN at 298 K.

Figure S8. Femtosecond transient absorption features seen upon excitation of 1 (0.1 mM) at 400 nm. The changes

shown after the sample is subject to laser pulse in deoxygenated PhCN at 298 K.

S6

0

1

2

3

0 1000 2000 3000

10

2 !

Ab

s a

t 6

70

nm

Time, ps

0

1

2

0 1000 2000 3000

10

2 !

Ab

s a

t 6

70

nm

Time, ps

(a) (b)

Figure S9. (a) Decay in the absorption intensity of 12* recorded at 670 nm after excitation at 400 nm. The sample

used for the analysis contained 0.3 mM of 2. Based on curve fitting, the decay rate was found to be 4.3 x 108 s-1 with

R2 = 0.992. (b) Decay of absorption at 670 nm attributed to 12* as observed post excitation at 400 nm for a sample

containing 1 (0.5 mM) and 2 (0.3 mM). Based on these data, the decay rate was calculated to be 4.7 × 108 s–1 with an

R2 = 0.992. Both samples were done in deoxygenated benzonitrile at 298 K. These decay rates were collected in the

Osaka laboratory and are relatively close to the decay rate found in the Seoul laboratory, namely 3.3 × 108 s−1 as

described in the text. The results in this figure reflect experiments carried out at higher concentrations than used in

the Seoul laboratory (50 µM for both 1 and 2).

Figure S10. (a) Nanosecond laser flash photolysis absorption profile of 32* (0.1 mM) as observed 2 µs (black) and

10 µs (red) after excitation at 355 nm in deoxygenated benzonitrile at 298 K. (b) Decay of absorption of 32* at 450

nm post excitation at 355 nm in benzonitrile at 298 K. Based on curve fitting, the decay rate was found to be 1.1 x

104 sec–1 with R2 = 0.994 (inset).

S7

0.000

0.002

0.004

0.006

0.008

0.010

400 600 800 1000 1200

MTTF100uMex355-5mJ-TA

10 µs

!A

bs

Wavelength, nm!

Figure S11. Nanosecond laser flash photolysis absorption spectrum observed upon excitation of 1 (0.3 mM) at 355

nm in deoxygenated benzonitrile at 298 K

To determine the absorption spectra of the radical anion 2•– and the radical cation 1•+, chemical redox proc-

esses were carried out while monitoring the changes in the UV–Vis–NIR spectrum. The chemical oxidant

tris(4-bromophenyl)ammoniumyl hexachloridoantimonate, also known as “magic blue,” was used to induce

the radical cation 1•+. The titration 1 with up to 1 equivalent of “magic blue” is shown in Figure S11. The

emergence of absorption features at 430, 620, and 930 nm following oxidation of 1 is fully consistent with the

oxidation of TTF to TTF•+.1 The naphthalene radical anion was used to reduce porphyrin 2 chemically. The

naphthalene radical anion was prepared in deoxygenated, anhydrous tetrahydrofuran (THF) following a litera-

ture procedure.2 The UV spectrum for the titration of 2 with the naphthalene radical anion is shown in Figure

S12. The absorbance bands for the porphyrin radical anion 2•– are centered at 570, 618, and 850 nm.

S8

1.0

0.8

0.6

0.4

0.2

0.0

Ab

so

rba

nce

(a

.u.)

1000800600400

Wavelength (nm)

1

1 + 1 equiv. oxidant

420 nm

930 nm

620 nm

Figure S12. Titration of 1 (50 mM, black line) with up to 1 equivalent of the chemical oxidant “magic blue”

(final spectrum shown with a red line) at 298 K in benzonitrile.

4

3

2

1

0

Ab

so

rba

nce

(a

.u.)

11001000900800700600500

Wavelength (nm)

naphth. radical anion (nra)

2

2 + 1 µL nra

2 + 2 µL nra

2 + 3 µL nra

2 + 4 µL nra

2 + 5 µL nra

2 + 6 µL nra

850 nm

570 nm

618 nm

Figure S13. Titration of 2 (0.3 mM, benzonitrile) with the naphthalene radical anion at 298 K. Shown in this

figure are the absorbance spectra of the naphthalene radical anion (black), porphyrin 2 (red), 2 with 1 mL

naphthalene radical anion added (red-orange), 2 with 2 mL naphthalene radical anion (orange), 2 with 3 mL

naphthalene radical anion (yellow), 2 with 4 mL naphthalene radical anion (green), 2 with 5 mL naphthalene

radical anion (blue), and 2 with 6 mL naphthalene radical anion (purple).

S9

Figure S14. (a) Decay time profiles of absorbance at 670 nm with various laser intensities. Inset: First-order

plots. Rate of intramolecular back electron transfer (kBET) (b) vs laser intensity for a sample containing 0.3

mM 1 and 0.1 mM 2 (left) and (c) vs [1] for a sample containing 0.3 mM 2 (right) in deoxygenated benzoni-

trile at 298 K.

S10

0

1

2

3

0 0.5 1.0 1.5 2.0

10

–6 [

1•+

]–1,

M–1

Time, ms

0

1 106

2 106

3 106

0 0.5 1 1.5 2

2nd-oeder-decay

500 µM400 µM300 µM200 µM100 µM

y = 2.205e+5 + 1.0503e+6x R2= 0.98581

y = 1.9927e+5 + 1.1283e+6x R2= 0.98743

y = 1.0014e+5 + 8.6178e+5x R2= 0.98791

y = 81442 + 9.8632e+5x R2= 0.98783

y = 1.3754e+5 + 8.095e+5x R2= 0.99348

[BT

TF

C4

P•+

]–1,

M–1

Time, ms

(a) ! (b) !

Figure S15. Second order decay analysis of the back electron transfer process at various concentrations of 1 as stud-

ied in the presence of 0.3 mM of 2 in deoxygenated benzonitrile at 298 K (left). Rate of back electron transfer versus

concentration of 1 in a 0.3 mM solution of 2 in PhCN at 298 K. On the basis of these analyses, the intermolecular

electron transfer rate was found to be 9.8 × 108 M–1 sec–1 (right).

–0.5

1.0

0.5

0

ln(k

BE

T T

–1, s

–1 K

–1)

2.8 3.83.23.0

103 T –1 , K–1

3.4 3.6

Figure S16 Eyring plot constructed by plotting the observed changes in the rate of back electron transfer

(kBET) versus temperature in benzonitrile. The concentrations of 1 and 2 were 0.3 mM and 0.1 mM, respec-

tively. ΔG≠ was found to be 14 kcalmol−1, ΔS≠ to be −40 calK−1mol−1, and ΔH≠ to be 1.9 kcalmol−1.

S11

-1.0

-0.5

0.0

0.5

1.0

330325320315

Field Strength (mT)

1·+

g = 2.0067

2·-

g = 2.0037

Figure S17. Normalized ESR spectra for chemically induced BTTF-C4P (1+) and porphyrin carboxylate (2•–) in

deaerated PhCN at 77 K.

Supporting References

(1) Park, J. S.; Karnas, E.; Ohkubo, K.; Chen, P.; Kadish, K. M.; Fukuzumi, S.; Bielawski, C. W.; Hudnall, T. W.;

Lynch, V. M.; Sessler, J. L. Ion-Mediated Electron Transfer in a Supramolecular Donor-Acceptor Ensemble.

Science 2010, 329, 1324-1327.

(2) Corey, E. J.; Gross, A. W. tert-BUTYL-tert-OCTYLAMINE. Org. Synth. 1987, 65, 166-170.