A bioinspired redox relay that mimics radical … · Laboratoire de Chimie Physique, Groupe...

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NATURE CHEMISTRY | www.nature.com/naturechemistry 1 SUPPLEMENTARY INFORMATION DOI: 10.1038/NCHEM.1862 A bioinspired redox relay that mimics radical interactions of the Tyr-His pairs of photosystem II Jackson D. Megiatto, Jr. 1# , Dalvin D. Méndez-Hernández 1 , Marely E. Tejeda-Ferrari 1 , Anne- Lucie Teillout 1,3 , Manuel J. Llansola-Portolés 1 , Gerdenis Kodis 1 , Oleg G. Poluektov 2 *, Tijana Rajh 2 *, Vladimiro Mujica 1 , Thomas L. Groy 1 , Devens Gust 1 *, Thomas A. Moore 1 * and Ana L. Moore 1 * 1 Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604, USA E-mail: [email protected] ; [email protected] ; [email protected] 2 NanoBio Interface Group, Center for Nanoscale Materials and Chemistry Division, Argonne National Laboratory Argonne, IL 60439, USA E-mail: [email protected] ; [email protected] 3 Laboratoire de Chimie Physique, Groupe d'Electrochimie et de Photoélectrochimie, UMR 8000, CNRS, Université Paris-Sud, Batiment 350, 91405 Orsay Cedex, France. # Current address: Institute of Chemistry, Campinas State University (UNICAMP), P.O. Box 6154, Campinas, SP, 13084-861, Brazil. © 2014 Macmillan Publishers Limited. All rights reserved.

Transcript of A bioinspired redox relay that mimics radical … · Laboratoire de Chimie Physique, Groupe...

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SUPPLEMENTARY INFORMATIONDOI: 10.1038/NCHEM.1862

1

A bioinspired redox relay that mimics radical interactions of

the Tyr-His pairs of photosystem II

Jackson D. Megiatto, Jr.1#, Dalvin D. Méndez-Hernández1, Marely E. Tejeda-Ferrari1, Anne-

Lucie Teillout1,3, Manuel J. Llansola-Portolés1, Gerdenis Kodis1, Oleg G. Poluektov2*, Tijana

Rajh2*, Vladimiro Mujica1, Thomas L. Groy1, Devens Gust1*, Thomas A. Moore1* and Ana L.

Moore1*

1Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604, USA E-mail:

[email protected] ; [email protected] ; [email protected]

2 NanoBio Interface Group, Center for Nanoscale Materials and Chemistry Division, Argonne National Laboratory

Argonne, IL 60439, USA E-mail: [email protected]; [email protected]

3 Laboratoire de Chimie Physique, Groupe d'Electrochimie et de Photoélectrochimie, UMR 8000, CNRS, Université

Paris-Sud, Batiment 350, 91405 Orsay Cedex, France.

# Current address: Institute of Chemistry, Campinas State University (UNICAMP), P.O. Box 6154, Campinas, SP,

13084-861, Brazil.

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2

SUPPLEMENTARY INFORMATION

Table of contents :

1 – Materials 2

2 – Nuclear Magnetic Resonance 2

3 – Electron Paramagnetic Resonance (EPR) Section 3

4 – Theoretical Calculations 5

5 – Electrochemical Section 10

6 – Crystal Structure and X-Ray Data 15

7 – References 35

1 – Materials All chemicals were purchased from Aldrich, Alfa Aesar, and Acros and were used

without further purification. Solvents were obtained from EM Science and were used as received

unless otherwise noted.

2 – Nuclear Magnetic Resonance

1H-NMR spectra were recorded on a Varian spectrometer at 500 MHz. NMR samples

were prepared in deuterated solvents with tetramethylsilane as an internal reference using

Wilmad 528-PP 5 mm NMR tubes. Deuterated chloroform was distilled from CaH, whereas

deuterated acetone and acetonitrile were used as received. Chemical shifts (δ) are reported in

parts per million (ppm) and referenced to the residual solvent peak.

2

SUPPLEMENTARY INFORMATION

Table of contents :

1 – Materials 2

2 – Nuclear Magnetic Resonance 2

3 – Electron Paramagnetic Resonance (EPR) Section 3

4 – Theoretical Calculations 5

5 – Electrochemical Section 10

6 – Crystal Structure and X-Ray Data 15

7 – References 35

1 – Materials All chemicals were purchased from Aldrich, Alfa Aesar, and Acros and were used

without further purification. Solvents were obtained from EM Science and were used as received

unless otherwise noted.

2 – Nuclear Magnetic Resonance

1H-NMR spectra were recorded on a Varian spectrometer at 500 MHz. NMR samples

were prepared in deuterated solvents with tetramethylsilane as an internal reference using

Wilmad 528-PP 5 mm NMR tubes. Deuterated chloroform was distilled from CaH, whereas

deuterated acetone and acetonitrile were used as received. Chemical shifts (δ) are reported in

parts per million (ppm) and referenced to the residual solvent peak.

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3 – Electron Paramagnetic Resonance (EPR) Section

X-band EPR spectra were recorded on a Bruker Elexsys E580 spectrometer equipped

with standard Bruker resonator with optical access and a variable-temperature cryostat (Air

Products). Samples at 4.2 K were illuminated directly in the spectrometer cavity using a LX 300

UV xenon lamp (Atlas Specialty Lighting, Tampa, FL) with a 520 nm cut off filter. Temperature

was controlled using Lake Shore temperature controller model 321-Autotuning. The background

EPR signal was measured for each sample before illumination. The g-values were calibrated by

comparison to the Mn2+ standard in a SrO matrix (g = 2.0012 ± 0.0002)1 and coal sample No 4

from Argonne coal collection (g = 2.00285 ± 0.00005).2

Supplementary Figure S1. Photoinduced X-band (9.5 GHz) EPR spectrum, obtained after illumination of an acetonitrile suspension of triad-1 (BiP–PF10–TiO2) with light of wavelengths greater than 520 nm at 4.2 K, modulation amplitude 2 G, power 0.05 mW. Red: signal from BiP–PF10

•+; blue: signals from TiO2•– lattice.

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Supplementary Figure S2. Photoinduced X-band (9.5 GHz) EPR spectra, obtained after illumination of an acetonitrile suspension of triad-1 (red) and dyad-2 (black) with light of wavelengths greater than 520 nm at 4.2 K, modulation amplitude 5 G, power 2 mW. Note higher power and modulation amplitude that was used to enhance signal intensity and signal to noise ratio.

Supplementary Figure S3. Integrated (9.5 GHz) X-band spectrum of triad-1 (BiP–PF10–TiO2) at low power (0.02 mW) to avoid saturation and low modulation amplitude (2 G). The area under each radical species signal is proportional to the number of spins: BiP–PF10

•+, red, field 3270–3336 G and TiO2

•–, blue, field 3336–3450 G. The number of spins (radicals) was determined using calibrated weak pitch in a KCl sample under the same conditions (1.15 × 1013 spins cm-1, Bruker Instruments). It was determined to be 3.8 × 1013 spins cm-1 for BiP–PF10

•+ and 4.5 × 1013 spin cm–1 for TiO2

•–.

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4 – Theoretical Calculations

The theoretical structures were optimized with Gaussian 093 at the B3LYP/6-31G(d,p)4-9

level of theory using the Conductor-like Polarizable Continuum Model (CPCM)10,11 for the

acetonitrile environment. The g-values for all the structures were obtained with ORCA12 at the

B3LYP/EPR-II13 level of theory using the Conductor-Like Screening Model (COSMO)14 to

simulate the acetonitrile environment.

The spin-density population of the structure that corresponds to the carboxylic acid form

of dyad-2 depicted as a radical cation after the proton transfer from the phenol to the

benzimidazole is shown in Supplementary Fig. S4. In agreement with the experimental data, a

very strong intra-molecular hydrogen bond can be inferred from the small dihedral angle (less

than 2°) between the phenol and imidazole planes of the BiP moiety in the optimized structure.

The spin-density distribution reveals that the unpaired electron is delocalized to some extent

between both the porphyrin and the phenol rings. The ratio of the unpaired spin populations

(PF10:BiP) is approximately 35:65. This explains the observation that the gx-value of dyad-2 is

lower than those reported for other BiP systems.15,16

Supplementary Figure S4. Spin density (the orange and green colors show positive and negative spin densities, respectively) for a structure of the carboxylic acid form of dyad-2 as a radical cation after PCET geometry optimized using Gaussian 09 at the B3LYP/6-31G(d,p) level of theory and the Conductor-like Polarizable Continuum Model (CPCM) to include the

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acetonitrile environment in the calculations. Carbon (grey), hydrogen (white), nitrogen (blue), fluorine (cyan) and oxygen (red).

Supplementary Figure S5. Structures of the carboxylic acid form of dyad-2, as a radical cation after PCET, geometry optimized with Gaussian 09 at the B3LYP/6-31G(d,p) level of theory and the Conductor-like Polarizable Continuum Model (CPCM) to include the acetonitrile environment in the calculations. Explicit water and/or acetonitrile molecules are included where indicated in calculated structures.

Calculations of the anisotropic g-values for the series of radical cation structures

presented in Supplementary Fig. S5 and Supplementary Table S1 were performed following

methodology from the literature.16 Structures with solvent molecules involved in hydrogen bonds

with N–H sites were based on the fact that the distal N–H proton interacts strongly with solvent

molecules as revealed by 1H-NMR studies. Solvent molecules binding to the newly formed N–H

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bond were chosen based on the expectation of that this new N–H site would behave similarly to

the distal N–H (See Fig. 4 and Fig. 5 in the manuscript and discussion therein).

Supplementary Table S1. Comparison between experimental g values for the carboxylic acid form of dyad-2, as a radical cation, initially formed at 13 K and after annealing at 100 K and returned to 13 K for the measurement in two states and the calculated g values for structures A•+–I•+ obtained with ORCA at the B3LYP/EPRII level of theory and using COSMO to simulate the acetonitrile environment.

gx gy gz

Exp. at 13 K 2.0056 2.0042 2.0022

Exp. after annealing at 100 K 2.0061 2.0042 2.0022

Theoretical Structure A•+ 2.0052 2.0041 2.0024

Theoretical Structure B•+ 2.0060 2.0044 2.0023

Theoretical Structure C•+ 2.0041 2.0032 2.0025

Theoretical Structure D•+ 2.0052 2.0040 2.0024

Theoretical Structure E•+ 2.0060 2.0045 2.0023

Theoretical Structure F•+ 2.0063 2.0044 2.0023

Theoretical Structure G•+ 2.0062 2.0044 2.0023

Theoretical Structure H• 2.0066 2.0047 2.0024

Theoretical Structure I•+ 2.0056 2.0042 2.0024

It is important to clarify that in our model we take into account explicitly two solvent

molecules and the solvent reorganization is defined in the following way. For example, in the

case of A•+ reorganizing to form B•+, we start with a structure in which the two explicit water

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molecules are near the positions shown in A•+ and then run the geometry optimization program

to yield the actual structure shown as A•+. We then relocate the water molecule near the newly

formed N–H site and run the geometry optimization program again to yield structure B•+. The

change in solvent structure between the two geometry-optimized systems is the reorganization of

the explicit water (solvent). The remaining solvent effect is included using the conventional

dielectric model. Other reorganizations in the system include a change in the BiP dihedral angle

and concomitant changes in the distance between phenoxyl O and N–H site.

The calculated g-values for the radical cation of the carboxylic acid form of dyad-2

without taking into account hydrogen bond formation involving the new (proximal) N–H site and

an explicit solvent molecule yields results that are very close to the experimental g-values

observed at 13 K (Supplementary Table S1 and Supplementary Fig. S5, A•+, D•+ and I•+). This

agreement supports the interpretation that at 13 K the solvent molecules do not have enough

energy to reorganize to form a hydrogen bond with the newly formed (proximal) N–H site. Upon

warming of the solution to 100 K the energy available for solvent reorganization increases and

hydrogen bond formation involving the newly formed (proximal) N–H site is possible resulting

in an increase of the gx-value. The calculated g-values for radical cations including this new

hydrogen bond with solvent molecules are in excellent agreement with those observed at 100 K

(Supplementary Table S1 and Supplementary Fig. S5, B•+, E•+, F•+ and G•+). The calculated gx-

value for a structure before proton transfer (C•+) results in a value much lower than that observed

experimentally even at 13 K. For the case where the distal N–H proton is deprotonated by a base

yielding a neutral radical (H•) the calculated gx-value is much higher than that observed

experimentally even after annealing at 100 K.

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Supplementary Table S2. Comparison between calculated structural parameters for structures A•+–I•+. The structures are geometry optimized with Gaussian 09 at the B3LYP/6-31G(d,p) level of theory and the Conductor-like Polarizable Continuum Model (CPCM) to include the acetonitrile environment in the calculations. (For structures see Supplementary Fig. S5).

Structure Charge, multiplicity

Number of explicit water

molecules

Number of explicit

acetonitrile molecules

BiP O–H distance

(Å)

BiP N–H distance

(Å)

BiP N–O distance

(Å)

BiP dihedral angle (°)

∆E relative to structure

C•+ (kcal/mol)a

A•+ 1,2 2 0 1.88 1.02 2.62 1.82 -19.05

B•+ 1,2 2 0 2.14 1.03 2.72 7.12 -21.93

C•+ 1,2 0 0 1.02 1.58 2.53 -0.05 Reference

D•+ 1,2 0 0 1.84 1.02 2.60 -1.69 -2.76

E•+ 1,2 1 0 2.34 1.04 2.80 24.4 -10.15

F•+ 1,2 1 1 2.01 1.02 2.67 3.87 -17.85

G•+ 1,2 0 1 1.99 1.02 2.66 2.80 -5.79

H• 0,2 0 0 1.94 1.02 2.65 -0.04 -

I•+ 1,2 1 0 1.86 1.02 2.62 1.55 -14.45

a) ∆E relative to structure C•+ (kcal/mol) was calculated by the following equation:

∆E = E(Structure) – E(C•+) – (E(explicit solvent) × number explicit solvent molecules).

The structure with the highest energy is C•+, corresponding to BiP–PF10•+ before the

proton is transferred from the phenol to the benzimidazole. The energy of this structure (C•+)

was used as the reference to calculate ∆E. Upon proton transfer to the benzimidazole (D•+), the

energy decreases. Adding a hydrogen bond acceptor to the distal N–H of the BiP further lowers

the energy (I•+). Addition of a water molecule hydrogen bonded to the nearby the N–H.....O bond

of the BiP stabilizes the system further (A•+ and B•+), but the gx-value increases only when a

bifurcated hydrogen bond involving the newly formed N–H site is formed (B•+). Structure E•+

shows the effect of water hydrogen bonded to the newly formed N–H site without the distal

water, and structures F•+ and G•+ show the effect of acetonitrile hydrogen bonded to the newly

formed N–H site with and without the distal water. Notice that acetonitrile is not hydrogen

bonded to the distal N–H in any of the structures. Due to steric considerations when an

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acetonitrile molecule is included at this site the structures cannot be geometry optimized without

a serious distortion of the porphyrin macrocycle.

5 – Electrochemical Section

Cyclic voltammetry was performed with a CHI 650C potentiostat (CH Instrument) with

scan rates ranging from 0.1 V/s and 0.5V/s. For scan rates faster than 1 V/s, cyclic voltammetry

was performed with a potentiostat equipped with EG&G Parc Model 175 and Princeton applied

research Model 176 current follower. A custom glass cell with Teflon top accommodating a

three electrode setup and 1–2 mL of solution was used. The working electrode was either a

platinum (1.5 mm diameter) or a glassy carbon (1 mm diameter) disc electrode as indicated for

the particular experiment. The working electrode was cleaned between experiments by polishing

with alumina (50 mm diameter) slurry followed by solvent rinses. The counter electrode was a

platinum grid. The potential of the pseudoreference electrode was determined using the

ferrocenium-ferrocene redox couple as an internal standard (with Em taken as 0.45 V vs. SCE in

acetonitrile). The compound of interest was dissolved in acetonitrile (Aldrich, 99.99%) to yield a

solution with concentration between 4 × 10-4 and 8 × 10-4, to which was added

tetrabutylammonium hexafluorophosphate at a concentration of 100 mM as a supporting

electrolyte for all experiments. Prior to any experiment, the solution was purged with argon for 2

minutes and then run under an argon atmosphere.

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Supplementary Figure S6. Cyclic voltammetry of the porphyrin model compound S6 lacking the BIP moiety. The voltammogram was taken in acetonitrile with a platinum working electrode. and at a scan rate of 100 mV s-1. Sequential reductions of the porphyrin core occurred at -0.91 V and -1.36 V vs. SCE, and an oxidation was observed at 1.29 V vs. SCE.

-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0-1.5x10-5

-1.0x10-5

-5.0x10-6

0.0

5.0x10-6

1.0x10-5

1.5x10-5

Curr

ent i

(am

p.)

Potential E (Volts, vs. SCE)

Fc/Fc+

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Supplementary Figure S7. Cyclic voltammetry of dyad-2. The voltammogram was taken in acetonitrile with a platinum working electrode and at a scan rate of 100 mV s-1. Sequential reductions of the porphyrin core occurred at -1.02 V and -1.52 V vs. SCE. An oxidation peak was observed at 1.00 V vs. SCE corresponding to the BIP group, whereas the porphyrin core oxidation took place at about 1.65 V vs. SCE.

-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0-1.0x10-5-8.0x10-6-6.0x10-6-4.0x10-6-2.0x10-6

0.02.0x10-64.0x10-66.0x10-68.0x10-61.0x10-51.2x10-51.4x10-5

Curr

ent i

(Am

p.)

Potential E (Volts vs. SCE)

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Supplementary Table S3: Redox potentials (V vs. SCE) for reduction and oxidation of the compounds shown on the left. The peak to peak separation (mV) is listed in parentheses for redox processes exhibiting either reversible, or quasi-reversible electrode kinetics.

a) E = Epeak irreversible process.

b) E = E1/2 reversible or quasi-reversible process; numbers between parentheses are given in mV

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5.1 – Electrochemical Kinetic Study17-19 Variable scan rate cyclic voltammetry studies of dyad-2 on glassy carbon and gold

electrodes at scan rates varying from 0.1 to 200 V/s (Supplementary Fig. S8) in acetonitrile

reveal that the phenol oxidation is reversible with the apparent standard potentials independent of

the scan rate in the range investigated. These findings indicate an extremely fast phenolic proton

transfer reaction to the benzimidazole moiety upon electrochemical oxidation of dyad-2. The

reversibility of the phenoxyl/phenol couple in dyad-2 at high scan rates clearly reveals the ability

of the proton to easily shuttle between the phenolic oxygen and the nitrogen atom of the

benzimidazole in the corresponding Bi–PhOH reduced and BiH+–PhO• oxidized forms.

However, further variable scan rate cyclic voltammetry experiments with dyad-2 dissolved in

acetonitrile containing 2% (v/v) of either regular or deuterated methanol, followed by

comparison of the experimental data with those afforded by digital simulations using the

DigiSim software for estimation of the apparent rate constants in the two solvent systems (kappH

= 0.054 ± 0.009 and kappD = 0.056 ± 0.006 in regular and deuterated methanol, respectively),

disclose a negligible kinetic isotope effect (KIE) for the electrochemical oxidation of the phenol.

Supplementary Figure S8. Left: normalized cyclic voltammograms (i is the current and v is the scan rate) of the BIP group PCET of the dyad-2 at a glassy carbon electrode (1mm diameter) in ACN + 2% MeOD at 10 V/s (black), 50 V/s (red), 100 V/s (blue), 200 V/s (green). Right: Anodic (upper symbol) and cathodic (lower symbol) peak potentials as a function of the log of

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scan rate. Simulation of the ‘‘trumpet plot’’ (full line) leads to the determination of the apparent standard rate constant ( from the peak current density:

, where is the electroactive species bulk concentration). In ACN + 2% MeOH, experimental peak potential (red circle) and corresponding simulation (red full line). In ACN + 2% MeOD, experimental peak potential (black square) and corresponding simulation (grey full line).

6 – Crystal Structure and X-Ray Data

A clear dark red needle-like specimen of C57H34F10N6O3, trimmed to approximate

dimensions 0.07 mm × 0.21 mm × 0.48 mm, was used for the X-ray crystallographic analysis.

The X-ray intensity data were measured as indicated in Supplementary Table S4 below with a

Bruker SMART APEX 2D CCD diffractometer.

Supplementary Table S4: Data collection details for dyad-2.

Axis dx/mm 2θ/° ω/° φ/° χ/° Width/° Frames Time/s Wavelength/Å Voltage/kV Current/mA Temperature/K

Omega 50.210 -34.00 -34.00 0.00 54.78 0.50 364 120.00 0.71073 50 30.0 123

Omega 50.210 -34.00 -34.00 120.00 54.78 0.50 364 120.00 0.71073 50 30.0 123

Omega 50.210 -34.00 -34.00 240.00 54.78 0.50 364 120.00 0.71073 50 30.0 123

A total of 1092 frames were collected. The total exposure time was 36.40 hours. The

frames were integrated with the Bruker SAINT20 software package using a narrow-frame

algorithm. The integration of the data using a monoclinic unit cell yielded a total of 47693

reflections to a maximum θ angle of 25.10° (0.84 Å resolution), of which 10916 were

independent (average redundancy 4.369, completeness = 99.4%, Rint = 9.06%, Rsig = 8.57%) and

5465 (50.06%) were greater than 2σ(F2). The final cell constants of a = 19.934(4) Å, b =

10.691(2) Å, c = 29.550(7) Å, β = 101.580(3)°, volume = 6169.(2) Å3, are based upon the

refinement of the XYZ-centroids of 3448 reflections above 20 σ(I) with 4.434° < 2θ < 40.09°.

Data were corrected for absorption effects using the multi-scan method (SADABS).21 The ratio

of minimum to maximum apparent transmission was 0.762. The calculated minimum and

maximum transmission coefficients (based on crystal size) are 0.9573 and 0.9941. CCDC

deposition number 949079.

126 .10.5 −−= scmDRTFDvCFjp

∞= 446.0/ ∞C

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The structure was solved and refined using the Bruker SHELXTL22 Software Package,

using the space group P 1 2/c 1, with Z = 4 for the formula unit, C57H33F10N6O3. After fruitless

attempts at modeling the disordered solvent in the structure, the PLATON SQUEEZE23

algorithm was applied to the partially solved structure to produce a solvent-free data set upon

which the final refinements were performed. There were no significant changes in the structure

of the primary molecule between the original solution and the final solvent-free model. The final

anisotropic full-matrix least-squares refinement on F2 with 693 variables converged at R1 =

7.74%, for the observed data and wR2 = 22.76% for all data. The goodness-of-fit was 0.978. The

largest peak in the final difference electron density synthesis was 0.323 e-/Å3 and the largest hole

was -0.395 e-/Å3 with an RMS deviation of 0.063 e-/Å3. On the basis of the final model, the

calculated density was 1.120 g/cm3 and F(000), 2124 e-. The depictions of the crystallographic

structure were produced by the Bruker XShell24 display software, which is illustrated in

Supplementary Fig. S9. When run through IUCR's CheckCIF routine, the crystal structure .cif

files produced 2 Level B alerts. These were on account of minor rotational disorder about the

axis defined by C5 and C15, as indicated by the elongated thermal parameters perpendicular to

this axis.

Supplementary Figure S9. Thermal ellipsoid plot of dyad-2 shown at the 50% probability level. Hydrogen atoms have been omitted for clarity.

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Supplementary Table S5. Sample and crystal data for dyad-2.

Identification code Megiatto_Compound_2

Chemical formula C57H33F10N6O3

Formula weight 1039.89

Temperature 123(2) K

Wavelength 0.71073 Å

Crystal size 0.07 x 0.21 x 0.48 mm

Crystal habit clear dark red needle

Crystal system Monoclinic

Space group P 1 2/c 1

Unit cell dimensions a = 19.934(4) Å α = 90°

b = 10.691(2) Å β = 101.580(3)°

c = 29.550(7) Å γ = 90°

Volume 6169.(2) Å3

Z 4

Density (calculated) 1.120 Mg/cm3

Absorption coefficient 0.091 mm-1

F(000) 2124

Supplementary Table S6. Data collection and structure refinement for dyad-2.

Theta range for data collection 1.90 to 25.10°

Index ranges -23<=h<=23, -12<=k<=12, -35<=l<=34

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Reflections collected 47693

Independent reflections 10916 [R(int) = 0.0906]

Coverage of independent reflections 99.4%

Absorption correction multi-scan

Max. and min. transmission 0.9941 and 0.9573

Structure solution technique direct methods

Structure solution program SHELXS-97 (Sheldrick, 2008)

Refinement method Full-matrix least-squares on F2

Refinement program SHELXL-97 (Sheldrick, 2008)

Function minimized Σ w(Fo2 - Fc

2)2

Data / restraints / parameters 10916 / 0 / 693

Goodness-of-fit on F2 0.978

Δ/σmax 0.001

Δ/σmean 0.000

Final R indices 5465 data; I>2σ(I) R1 = 0.0774, wR2 = 0.1946

all data R1 = 0.1501, wR2 = 0.2276

Weighting scheme w=1/[σ2(Fo2)+(0.1209P)2+0.0000P]

where P=(Fo2+2Fc

2)/3

Largest diff. peak and hole 0.323 and -0.395 eÅ-3

R.M.S. deviation from mean 0.063 eÅ-3

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Supplementary Table S7. Atomic coordinates and equivalent isotropic atomic displacement parameters (Å2) for dyad-2.

U(eq) is defined as one third of the trace of the orthogonalized Uij tensor.

x/a y/b z/c U(eq)

F1 0.73621(13) 0.5834(3) 0.91905(10) 0.0702(8)

F2 0.76968(15) 0.5159(3) 0.83868(11) 0.0934(10)

F3 0.76791(13) 0.6877(4) 0.77048(9) 0.0948(11)

F4 0.73458(12) 0.9256(3) 0.78366(9) 0.0833(10)

F5 0.70078(12) 0.9944(3) 0.86411(9) 0.0693(8)

F6 0.61751(14) 0.3111(3) 0.15356(10) 0.0752(8)

F7 0.59374(17) 0.4134(4) 0.23226(12) 0.1133(13)

F8 0.56954(13) 0.2663(4) 0.30166(9) 0.1165(14)

F9 0.57048(13) 0.0164(4) 0.29221(9) 0.1066(13)

F10 0.59588(13) 0.9121(3) 0.21475(9) 0.0754(8)

O1 0.10407(12) 0.1967(3) 0.13472(9) 0.0496(7)

O2 0.25113(16) 0.4226(3) 0.96729(17) 0.1049(16)

O3 0.18876(14) 0.5911(3) 0.96226(12) 0.0664(9)

N1 0.61115(13) 0.8308(3) 0.98553(10) 0.0360(8)

N2 0.57835(14) 0.9298(3) 0.06902(10) 0.0367(8)

N3 0.71975(14) 0.0171(3) 0.09885(10) 0.0370(8)

N4 0.74885(14) 0.9359(3) 0.01217(10) 0.0381(8)

N5 0.07442(15) 0.3964(3) 0.08522(12) 0.0501(9)

N6 0.96380(17) 0.4479(3) 0.05989(13) 0.0559(10)

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C1 0.63648(18) 0.7994(4) 0.94720(13) 0.0411(10)

C2 0.58396(18) 0.7292(4) 0.91677(14) 0.0449(10)

C3 0.53004(18) 0.7203(4) 0.93744(13) 0.0439(10)

C4 0.54524(17) 0.7834(3) 0.98070(12) 0.0360(9)

C5 0.50145(17) 0.8039(3) 0.01123(13) 0.0348(9)

C6 0.51695(17) 0.8771(4) 0.05146(12) 0.0354(9)

C7 0.46872(19) 0.9084(4) 0.08045(13) 0.0419(10)

C8 0.50212(19) 0.9782(4) 0.11512(13) 0.0446(10)

C9 0.57162(18) 0.9895(4) 0.10855(13) 0.0379(9)

C10 0.62423(18) 0.0499(4) 0.13967(13) 0.0414(10)

C11 0.69285(18) 0.0594(4) 0.13503(13) 0.0402(10)

C12 0.74705(19) 0.1169(4) 0.16806(14) 0.0491(11)

C13 0.80484(19) 0.1097(4) 0.15069(13) 0.0452(10)

C14 0.78811(17) 0.0501(4) 0.10661(13) 0.0371(9)

C15 0.83162(17) 0.0312(3) 0.07579(13) 0.0361(9)

C16 0.81285(17) 0.9806(3) 0.03143(13) 0.0368(9)

C17 0.85827(18) 0.9634(4) 0.99992(13) 0.0409(10)

C18 0.82205(18) 0.9111(4) 0.96123(14) 0.0431(10)

C19 0.75312(17) 0.8910(4) 0.96973(14) 0.0407(10)

C20 0.70114(18) 0.8291(4) 0.93913(13) 0.0447(10)

C21 0.71696(18) 0.7906(5) 0.89388(14) 0.0471(11)

C22 0.7349(2) 0.6710(5) 0.88628(16) 0.0580(13)

C23 0.7516(2) 0.6340(6) 0.8450(2) 0.0648(14)

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C24 0.7510(2) 0.7197(7) 0.81121(17) 0.0685(16)

C25 0.7348(2) 0.8406(7) 0.81780(16) 0.0664(15)

C26 0.71716(19) 0.8739(5) 0.85862(15) 0.0514(12)

C27 0.60716(18) 0.1078(5) 0.18134(14) 0.0464(11)

C28 0.6064(2) 0.2345(5) 0.18734(16) 0.0580(13)

C29 0.5936(2) 0.2882(7) 0.2277(2) 0.0776(17)

C30 0.5814(2) 0.2158(8) 0.26277(19) 0.079(2)

C31 0.5816(2) 0.0912(8) 0.25766(16) 0.078(2)

C32 0.5945(2) 0.0384(6) 0.21752(16) 0.0591(13)

C33 0.43409(17) 0.7365(4) 0.00109(12) 0.0374(9)

C34 0.3737(2) 0.7991(4) 0.98501(17) 0.0711(15)

C35 0.3125(2) 0.7333(5) 0.97526(18) 0.0707(15)

C36 0.30997(18) 0.6085(4) 0.98136(13) 0.0401(10)

C37 0.3702(2) 0.5460(5) 0.9983(2) 0.0772(17)

C38 0.4305(2) 0.6124(4) 0.00863(19) 0.0705(16)

C39 0.2437(2) 0.5414(4) 0.96952(14) 0.0460(11)

C40 0.1876(3) 0.3510(5) 0.9577(3) 0.145(4)

C41 0.90471(17) 0.0755(4) 0.09105(12) 0.0371(9)

C42 0.95144(18) 0.0037(4) 0.12105(13) 0.0414(10)

C43 0.01904(18) 0.0421(4) 0.13683(13) 0.0417(10)

C44 0.03811(17) 0.1571(4) 0.12131(13) 0.0385(10)

C45 0.99067(18) 0.2325(4) 0.09248(13) 0.0408(10)

C46 0.92391(18) 0.1890(4) 0.07797(13) 0.0425(10)

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C47 0.06948(19) 0.9617(4) 0.17212(14) 0.0522(11)

C48 0.0364(2) 0.8415(5) 0.18425(19) 0.0831(18)

C49 0.0926(2) 0.0386(5) 0.21686(15) 0.0667(14)

C50 0.1309(2) 0.9256(5) 0.15242(17) 0.0645(13)

C51 0.0096(2) 0.3572(4) 0.07912(14) 0.0470(11)

C52 0.0025(2) 0.5523(4) 0.05325(17) 0.0582(12)

C53 0.9842(2) 0.6704(5) 0.03606(19) 0.0752(15)

C54 0.0367(3) 0.7536(5) 0.03484(18) 0.0709(14)

C55 0.1048(2) 0.7210(5) 0.04931(17) 0.0639(13)

C56 0.1224(2) 0.6042(4) 0.06656(16) 0.0569(12)

C57 0.0707(2) 0.5196(4) 0.06943(15) 0.0506(11)

Supplementary Table S8. Bond lengths (Å) for dyad-2.

F1-C22 1.344(5) F2-C23 1.337(6)

F3-C24 1.357(5) F4-C25 1.357(6)

F5-C26 1.347(5) F6-C28 1.343(5)

F7-C29 1.344(7) F8-C30 1.333(6)

F9-C31 1.350(7) F10-C32 1.354(6)

O1-C44 1.362(4) O1-H1 0.84

O2-C39 1.281(5) O2-C40 1.459(5)

O3-C39 1.198(5) N1-C1 1.371(5)

N1-C4 1.388(4) N2-C6 1.353(4)

N2-C9 1.361(5) N2-H2A 0.88

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N3-C11 1.366(5) N3-C14 1.381(4)

N4-C19 1.361(5) N4-C16 1.374(4)

N4-H4A 0.88 N5-C51 1.336(5)

N5-C57 1.394(5) N6-C51 1.374(5)

N6-C52 1.393(5) C1-C20 1.394(5)

C1-C2 1.446(5) C2-C3 1.342(5)

C2-H2 0.95 C3-C4 1.423(5)

C3-H3 0.95 C4-C5 1.393(5)

C5-C6 1.405(5) C5-C33 1.500(5)

C6-C7 1.450(5) C7-C8 1.332(5)

C7-H7 0.95 C8-C9 1.442(5)

C8-H8 0.95 C9-C10 1.406(5)

C10-C11 1.406(5) C10-C27 1.477(6)

C11-C12 1.440(5) C12-C13 1.354(5)

C12-H12 0.95 C13-C14 1.428(5)

C13-H13 0.95 C14-C15 1.393(5)

C15-C16 1.398(5) C15-C41 1.512(5)

C16-C17 1.435(5) C17-C18 1.345(5)

C17-H17 0.95 C18-C19 1.462(5)

C18-H18 0.95 C19-C20 1.398(5)

C20-C21 1.492(6) C21-C22 1.358(6)

C21-C26 1.371(6) C22-C23 1.384(7)

C23-C24 1.354(7) C24-C25 1.357(7)

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C25-C26 1.369(6) C27-C32 1.366(6)

C27-C28 1.366(6) C28-C29 1.392(7)

C29-C30 1.355(8) C30-C31 1.342(8)

C31-C32 1.383(7) C33-C38 1.349(6)

C33-C34 1.376(5) C34-C35 1.388(6)

C34-H34 0.95 C35-C36 1.349(6)

C35-H35 0.95 C36-C37 1.378(5)

C36-C39 1.482(5) C37-C38 1.375(6)

C37-H37 0.95 C38-H38 0.95

C40-H40A 0.98 C40-H40B 0.98

C40-H40C 0.98 C41-C46 1.352(5)

C41-C42 1.382(5) C42-C43 1.396(5)

C42-H42 0.95 C43-C44 1.392(5)

C43-C47 1.554(5) C44-C45 1.395(5)

C45-C46 1.394(5) C45-C51 1.461(5)

C46-H46 0.95 C47-C50 1.507(6)

C47-C48 1.520(6) C47-C49 1.546(6)

C48-H48A 0.98 C48-H48B 0.98

C48-H48C 0.98 C49-H49A 0.98

C49-H49B 0.98 C49-H49C 0.98

C50-H50A 0.98 C50-H50B 0.98

C50-H50C 0.98 C52-C53 1.383(6)

C52-C57 1.392(6) C53-C54 1.379(6)

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C53-H53 0.95 C54-C55 1.384(6)

C54-H54 0.95 C55-C56 1.368(6)

C55-H55 0.95 C56-C57 1.386(6)

C56-H56 0.95

Supplementary Table S9. Bond angles (°) for dyad-2.

C44-O1-H1 109.5 C39-O2-C40 115.2(4)

C1-N1-C4 108.9(3) C6-N2-C9 106.7(3)

C6-N2-H2A 126.7 C9-N2-H2A 126.7

C11-N3-C14 108.4(3) C19-N4-C16 106.2(3)

C19-N4-H4A 126.9 C16-N4-H4A 126.9

C51-N5-C57 105.4(3) C51-N6-C52 106.4(3)

N1-C1-C20 126.3(3) N1-C1-C2 107.4(3)

C20-C1-C2 126.2(4) C3-C2-C1 107.5(4)

C3-C2-H2 126.3 C1-C2-H2 126.3

C2-C3-C4 109.2(3) C2-C3-H3 125.4

C4-C3-H3 125.4 N1-C4-C5 125.4(3)

N1-C4-C3 107.0(3) C5-C4-C3 127.5(3)

C4-C5-C6 125.2(3) C4-C5-C33 116.5(3)

C6-C5-C33 118.2(3) N2-C6-C5 125.8(3)

N2-C6-C7 109.5(3) C5-C6-C7 124.7(3)

C8-C7-C6 107.2(3) C8-C7-H7 126.4

C6-C7-H7 126.4 C7-C8-C9 106.8(4)

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C7-C8-H8 126.6 C9-C8-H8 126.6

N2-C9-C10 126.0(3) N2-C9-C8 109.8(3)

C10-C9-C8 124.1(4) C11-C10-C9 125.6(4)

C11-C10-C27 116.2(3) C9-C10-C27 118.1(3)

N3-C11-C10 126.5(3) N3-C11-C12 108.2(3)

C10-C11-C12 125.3(4) C13-C12-C11 107.4(4)

C13-C12-H12 126.3 C11-C12-H12 126.3

C12-C13-C14 108.1(3) C12-C13-H13 126.0

C14-C13-H13 126.0 N3-C14-C15 125.3(3)

N3-C14-C13 107.9(3) C15-C14-C13 126.8(3)

C14-C15-C16 125.8(3) C14-C15-C41 116.7(3)

C16-C15-C41 117.5(3) N4-C16-C15 125.1(3)

N4-C16-C17 109.9(3) C15-C16-C17 125.0(3)

C18-C17-C16 107.7(3) C18-C17-H17 126.2

C16-C17-H17 126.2 C17-C18-C19 106.1(3)

C17-C18-H18 126.9 C19-C18-H18 126.9

N4-C19-C20 126.0(3) N4-C19-C18 109.9(3)

C20-C19-C18 124.0(4) C1-C20-C19 126.0(4)

C1-C20-C21 117.4(3) C19-C20-C21 116.6(3)

C22-C21-C26 116.4(4) C22-C21-C20 121.2(4)

C26-C21-C20 122.4(4) F1-C22-C21 120.3(4)

F1-C22-C23 117.5(5) C21-C22-C23 122.2(5)

F2-C23-C24 119.8(5) F2-C23-C22 120.9(5)

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C24-C23-C22 119.2(5) C23-C24-C25 120.4(5)

C23-C24-F3 121.2(6) C25-C24-F3 118.4(6)

C24-C25-F4 119.8(5) C24-C25-C26 119.0(5)

F4-C25-C26 121.2(6) F5-C26-C25 117.8(5)

F5-C26-C21 119.4(4) C25-C26-C21 122.8(5)

C32-C27-C28 115.4(5) C32-C27-C10 122.3(4)

C28-C27-C10 122.2(4) F6-C28-C27 120.0(4)

F6-C28-C29 118.1(5) C27-C28-C29 121.9(6)

F7-C29-C30 119.2(6) F7-C29-C28 120.0(6)

C30-C29-C28 120.8(6) F8-C30-C31 120.3(7)

F8-C30-C29 121.3(7) C31-C30-C29 118.4(6)

C30-C31-F9 119.9(6) C30-C31-C32 120.5(6)

F9-C31-C32 119.6(7) F10-C32-C27 119.1(5)

F10-C32-C31 117.9(5) C27-C32-C31 123.0(6)

C38-C33-C34 117.6(4) C38-C33-C5 121.0(3)

C34-C33-C5 121.4(4) C33-C34-C35 119.8(4)

C33-C34-H34 120.1 C35-C34-H34 120.1

C36-C35-C34 121.8(4) C36-C35-H35 119.1

C34-C35-H35 119.1 C35-C36-C37 118.4(4)

C35-C36-C39 120.2(4) C37-C36-C39 121.4(4)

C38-C37-C36 119.3(4) C38-C37-H37 120.4

C36-C37-H37 120.4 C33-C38-C37 123.0(4)

C33-C38-H38 118.5 C37-C38-H38 118.5

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O3-C39-O2 122.7(4) O3-C39-C36 124.6(4)

O2-C39-C36 112.7(4) O2-C40-H40A 109.5

O2-C40-H40B 109.5 H40A-C40-H40B 109.5

O2-C40-H40C 109.5 H40A-C40-H40C 109.5

H40B-C40-H40C 109.5 C46-C41-C42 119.3(3)

C46-C41-C15 120.5(3) C42-C41-C15 120.1(3)

C41-C42-C43 122.2(4) C41-C42-H42 118.9

C43-C42-H42 118.9 C44-C43-C42 117.3(3)

C44-C43-C47 121.8(3) C42-C43-C47 120.9(4)

O1-C44-C43 119.3(3) O1-C44-C45 119.6(3)

C43-C44-C45 121.0(3) C46-C45-C44 118.9(4)

C46-C45-C51 120.2(4) C44-C45-C51 120.8(3)

C41-C46-C45 121.3(4) C41-C46-H46 119.4

C45-C46-H46 119.4 C50-C47-C48 107.4(4)

C50-C47-C49 109.9(3) C48-C47-C49 108.5(4)

C50-C47-C43 110.4(4) C48-C47-C43 111.9(3)

C49-C47-C43 108.7(4) C47-C48-H48A 109.5

C47-C48-H48B 109.5 H48A-C48-H48B 109.5

C47-C48-H48C 109.5 H48A-C48-H48C 109.5

H48B-C48-H48C 109.5 C47-C49-H49A 109.5

C47-C49-H49B 109.5 H49A-C49-H49B 109.5

C47-C49-H49C 109.5 H49A-C49-H49C 109.5

H49B-C49-H49C 109.5 C47-C50-H50A 109.5

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C47-C50-H50B 109.5 H50A-C50-H50B 109.5

C47-C50-H50C 109.5 H50A-C50-H50C 109.5

H50B-C50-H50C 109.5 N5-C51-N6 112.3(4)

N5-C51-C45 123.0(4) N6-C51-C45 124.8(3)

C53-C52-C57 121.5(4) C53-C52-N6 132.1(4)

C57-C52-N6 106.3(4) C54-C53-C52 116.9(5)

C54-C53-H53 121.5 C52-C53-H53 121.5

C53-C54-C55 122.2(5) C53-C54-H54 118.9

C55-C54-H54 118.9 C56-C55-C54 120.5(4)

C56-C55-H55 119.8 C54-C55-H55 119.8

C55-C56-C57 118.7(4) C55-C56-H56 120.6

C57-C56-H56 120.6 C56-C57-C52 120.1(4)

C56-C57-N5 130.3(4) C52-C57-N5 109.5(3)

Supplementary Table S10. Anisotropic atomic displacement parameters (Å2) for dyad-2.

The anisotropic atomic displacement factor exponent takes the form: -2π2[ h2 a*2 U11 + ... + 2 h k a* b* U12 ]

U11 U22 U33 U23 U13 U12

F1 0.0603(18) 0.0771(19) 0.0736(19) -0.0158(17) 0.0146(14) 0.0057(14)

F2 0.075(2) 0.121(3) 0.085(2) -0.035(2) 0.0167(17) 0.0020(19)

F3 0.0479(17) 0.183(3) 0.0509(17) -0.0312(19) 0.0045(13) -0.0095(18)

F4 0.0366(15) 0.164(3) 0.0444(15) 0.0104(19) -0.0046(11) -0.0140(16)

F5 0.0440(15) 0.101(2) 0.0570(17) 0.0143(16) -0.0033(12) -0.0008(15)

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U11 U22 U33 U23 U13 U12

F6 0.0703(19) 0.0764(19) 0.0712(19) -0.0104(16) -0.0045(15) -0.0005(15)

F7 0.086(2) 0.137(3) 0.101(3) -0.060(2) -0.0182(19) 0.029(2)

F8 0.0394(16) 0.253(4) 0.0488(17) -0.059(2) -0.0099(13) 0.034(2)

F9 0.0397(16) 0.239(4) 0.0403(16) 0.014(2) 0.0050(12) 0.000(2)

F10 0.0508(17) 0.123(3) 0.0499(16) 0.0180(17) 0.0028(12) -0.0166(16)

O1 0.0232(14) 0.072(2) 0.0478(17) 0.0025(16) -0.0063(12) -0.0137(13)

O2 0.039(2) 0.042(2) 0.210(5) 0.026(2) -0.030(2) -0.0142(15)

O3 0.0216(16) 0.063(2) 0.104(3) 0.0109(18) -0.0112(15) -0.0039(14)

N1 0.0161(15) 0.053(2) 0.0373(18) 0.0037(16) 0.0003(13) -0.0006(14)

N2 0.0174(16) 0.050(2) 0.0408(19) 0.0037(16) 0.0014(13) -0.0043(14)

N3 0.0203(16) 0.055(2) 0.0331(18) 0.0083(16) -0.0010(13) -0.0044(14)

N4 0.0140(15) 0.061(2) 0.0368(19) 0.0065(17) -0.0020(13) -0.0035(14)

N5 0.0258(19) 0.065(3) 0.056(2) 0.0045(19) -0.0019(15) -0.0152(16)

N6 0.0310(19) 0.056(2) 0.076(3) 0.015(2) -0.0021(17) -0.0092(17)

C1 0.019(2) 0.060(3) 0.040(2) -0.001(2) -0.0032(16) -0.0048(18)

C2 0.024(2) 0.065(3) 0.042(2) -0.005(2) -0.0034(17) -0.0044(19)

C3 0.018(2) 0.062(3) 0.045(2) -0.003(2) -0.0081(17) -0.0090(18)

C4 0.023(2) 0.046(2) 0.035(2) 0.0101(19) -0.0045(16) -0.0048(17)

C5 0.0189(19) 0.042(2) 0.040(2) 0.0129(19) -0.0024(16) -0.0033(16)

C6 0.0213(19) 0.047(2) 0.035(2) 0.0079(19) -0.0024(16) -0.0071(17)

C7 0.022(2) 0.059(3) 0.042(2) 0.009(2) -0.0001(17) -0.0047(18)

C8 0.028(2) 0.069(3) 0.034(2) 0.005(2) -0.0011(17) -0.004(2)

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U11 U22 U33 U23 U13 U12

C9 0.023(2) 0.054(3) 0.034(2) 0.008(2) -0.0011(16) -0.0035(17)

C10 0.024(2) 0.061(3) 0.036(2) 0.003(2) -0.0033(17) -0.0036(18)

C11 0.024(2) 0.057(3) 0.035(2) 0.006(2) -0.0055(17) -0.0067(18)

C12 0.025(2) 0.081(3) 0.037(2) -0.006(2) -0.0042(17) -0.009(2)

C13 0.022(2) 0.067(3) 0.042(2) 0.001(2) -0.0048(17) -0.0062(19)

C14 0.0153(19) 0.051(2) 0.042(2) 0.006(2) -0.0028(16) -0.0004(16)

C15 0.0189(19) 0.043(2) 0.041(2) 0.0081(19) -0.0067(16) -0.0026(16)

C16 0.0183(19) 0.045(2) 0.043(2) 0.0098(19) -0.0035(16) -0.0046(16)

C17 0.0201(19) 0.052(3) 0.047(2) 0.005(2) -0.0009(17) -0.0093(17)

C18 0.023(2) 0.063(3) 0.043(2) 0.002(2) 0.0043(17) -0.0028(19)

C19 0.0180(19) 0.055(3) 0.045(2) 0.006(2) -0.0031(16) -0.0062(17)

C20 0.021(2) 0.069(3) 0.041(2) 0.000(2) -0.0016(17) 0.0027(19)

C21 0.015(2) 0.079(3) 0.043(3) -0.005(3) -0.0048(17) -0.002(2)

C22 0.038(3) 0.094(4) 0.040(3) -0.004(3) 0.001(2) -0.004(3)

C23 0.034(3) 0.085(4) 0.072(4) -0.019(3) 0.002(2) -0.002(2)

C24 0.032(3) 0.130(5) 0.040(3) -0.030(4) -0.002(2) -0.014(3)

C25 0.025(2) 0.127(5) 0.040(3) 0.003(3) -0.010(2) -0.016(3)

C26 0.021(2) 0.087(4) 0.042(3) -0.006(3) -0.0004(18) -0.002(2)

C27 0.021(2) 0.077(3) 0.037(2) -0.003(2) -0.0027(17) -0.004(2)

C28 0.032(2) 0.088(4) 0.049(3) -0.017(3) -0.003(2) 0.002(2)

C29 0.038(3) 0.114(5) 0.069(4) -0.035(4) -0.016(3) 0.020(3)

C30 0.023(3) 0.166(7) 0.041(3) -0.029(4) -0.010(2) 0.017(3)

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U11 U22 U33 U23 U13 U12

C31 0.018(2) 0.185(7) 0.029(3) -0.006(4) -0.0020(19) 0.004(3)

C32 0.022(2) 0.098(4) 0.053(3) 0.005(3) -0.0046(19) -0.007(2)

C33 0.0198(19) 0.051(3) 0.038(2) 0.0025(19) -0.0026(16) -0.0049(17)

C34 0.033(3) 0.063(3) 0.102(4) 0.034(3) -0.024(2) -0.011(2)

C35 0.026(2) 0.070(3) 0.103(4) 0.031(3) -0.019(2) -0.008(2)

C36 0.027(2) 0.044(3) 0.047(2) 0.011(2) 0.0001(17) -0.0016(18)

C37 0.030(3) 0.053(3) 0.136(5) 0.027(3) -0.012(3) -0.004(2)

C38 0.025(2) 0.047(3) 0.125(4) 0.022(3) -0.019(2) -0.006(2)

C39 0.027(2) 0.054(3) 0.051(3) 0.015(2) -0.0045(18) -0.012(2)

C40 0.045(3) 0.059(4) 0.292(10) 0.049(5) -0.058(4) -0.030(3)

C41 0.0188(19) 0.051(3) 0.038(2) 0.006(2) -0.0023(16) -0.0058(17)

C42 0.024(2) 0.055(3) 0.043(2) 0.005(2) -0.0006(17) -0.0055(18)

C43 0.019(2) 0.061(3) 0.041(2) -0.001(2) -0.0035(16) -0.0027(18)

C44 0.0180(19) 0.058(3) 0.038(2) -0.006(2) 0.0020(16) -0.0106(18)

C45 0.027(2) 0.049(3) 0.043(2) 0.001(2) 0.0004(17) -0.0108(18)

C46 0.021(2) 0.055(3) 0.047(2) 0.010(2) -0.0029(17) -0.0032(18)

C47 0.027(2) 0.073(3) 0.049(3) 0.013(2) -0.0103(18) -0.005(2)

C48 0.044(3) 0.093(4) 0.093(4) 0.043(3) -0.034(3) -0.009(3)

C49 0.039(3) 0.105(4) 0.049(3) 0.009(3) -0.009(2) -0.010(3)

C50 0.030(2) 0.080(3) 0.075(3) 0.001(3) -0.010(2) 0.007(2)

C51 0.031(2) 0.052(3) 0.056(3) 0.002(2) 0.0031(19) -0.008(2)

C52 0.041(3) 0.053(3) 0.078(3) 0.012(3) 0.006(2) -0.015(2)

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U11 U22 U33 U23 U13 U12

C53 0.044(3) 0.075(4) 0.105(4) 0.010(3) 0.013(3) -0.010(3)

C54 0.059(3) 0.063(3) 0.091(4) 0.018(3) 0.013(3) -0.013(3)

C55 0.050(3) 0.066(3) 0.077(3) -0.001(3) 0.014(3) -0.019(2)

C56 0.039(3) 0.065(3) 0.065(3) -0.005(3) 0.005(2) -0.016(2)

C57 0.033(2) 0.060(3) 0.058(3) -0.004(2) 0.007(2) -0.015(2)

Supplementary Table S11. Hydrogen atomic coordinates and isotropic atomic displacement parameters (Å2) for dyad-2.

x/a y/b z/c U(eq)

H1 1.1085 1.2672 0.1231 0.074

H2A 0.6154 0.9262 0.0572 0.044

H4A 0.7124 0.9363 0.0247 0.046

H2 0.5870 0.6956 -0.1125 0.054

H3 0.4883 0.6784 -0.0749 0.053

H7 0.4220 0.8839 0.0756 0.05

H8 0.4837 1.0136 0.1395 0.054

H12 0.7430 1.1531 0.1967 0.059

H13 0.8488 1.1391 0.1653 0.054

H17 0.9054 0.9851 0.0054 0.049

H18 0.8380 0.8913 -0.0661 0.052

H34 0.3739 0.8871 -0.0194 0.085

H35 0.2711 0.7775 -0.0360 0.085

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x/a y/b z/c U(eq)

H37 0.3702 0.4581 0.0028 0.093

H38 0.4714 0.5690 0.0217 0.085

H40A 0.1679 0.3478 -0.0145 0.217

H40B 0.1970 0.2658 -0.0515 0.217

H40C 0.1550 0.3913 -0.0673 0.217

H42 0.9371 0.9257 0.1312 0.05

H46 0.8913 1.2400 0.0585 0.051

H48A 1.0206 0.7924 0.1561 0.125

H48B 0.9973 0.8618 0.1984 0.125

H48C 1.0699 0.7928 0.2060 0.125

H49A 1.1248 0.9892 0.2393 0.1

H49B 1.0525 1.0598 0.2299 0.1

H49C 1.1150 1.1157 0.2097 0.1

H50A 1.1632 0.8784 0.1755 0.097

H50B 1.1533 1.0013 0.1440 0.097

H50C 1.1161 0.8738 0.1249 0.097

H53 0.9376 1.6932 0.0256 0.09

H54 1.0257 1.8360 0.0237 0.085

H55 1.1396 1.7802 0.0473 0.077

H56 1.1691 1.5814 0.0764 0.068

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7 – References:

1. Rosenthal, J. & Yarmus, L. SrO:Mn as EPR marker and intensity standard. Rev. Sci. Instrum. 37,

381–381 (1966).

2. Brezgunov, A. Y., Dubinskii, A. A., Poluektov, O. G., Vorob’eva, G. A., Lebedev, Y. S.

Electron paramagnetic resonance of coals. New approaches to an old problem with

multifrequency electron paramagnetic resonance and spin echo. J. Chem. Soc., Faraday Trans.

86, 3185–3189 (1990).

3. Frisch, M. J. et al. Gaussian 09, Revision A.02 (Gaussian Inc., Wallingford, 2009).

4. Lee, C., Yang, W., Parr, R. G. Development of the Colle-Salvetti correlation-energy formula

into a functional of the electron density. Phys. Rev. B 37, 785–789 (1988).

5. Becke, A. D. Density-functional exchange-energy approximation with correct asymptotic

behavior. Phys. Rev. A 38, 3098–3100 (1988).

6. Becke, A. D. Density–functional thermochemistry. IV. A new dynamical correlation

functional and implications for exact–exchange mixing. J. Chem. Phys. 104, 1040–1046 (1996).

7. Francl, M. M. et. al. Self–consistent molecular orbital methods. XXIII. A polarization–type

basis set for second–row elements. J. Chem. Phys. 77, 3654–3665 (1982).

8. Harihan, P. C., Pople, J. A. The influence of polarization functions on molecular orbital

hydrogenation energies. Theor. Chim. Acta 28, 213–222 (1973).

9. Rassolov, V. A., Pople, J. A., Ratner, M. A., Windus, T. L. 6-31G* basis set for atoms K

through Zn. J. Chem. Phys. 109, 1223–1229 (1998).

© 2014 Macmillan Publishers Limited. All rights reserved.

NATURE CHEMISTRY | www.nature.com/naturechemistry 36

SUPPLEMENTARY INFORMATIONDOI: 10.1038/NCHEM.186236

10. Barone, V., Cossi, M. Quantum calculation of molecular energies and energy gradients in

solution by a conductor solvent model. J. Phys. Chem. A 102, 1995–2001 (1998).

11. Cossi, M., Rega, N., Scalmani, G., Barone, V. Energies, structures, and electronic properties

of molecules in solution with the C-PCM solvation model. J. Comput. Chem. 24, 669–681

(2003).

12. Neese, F. ORCA, An ab initio, density functional and semi-empirical program package,

Version 2.4.13, Max-Planck-Institut für Bioanorganische Chemie, Mülheim an der Ruhr,

Germany (2004).

13. V. Barone in Recent Advances in Density Functional Methods (Ed.: Chong, D. P.) (World

Scientific Publishing, Singapore, 1996).

14. A. Klamt, G. Schüürmann. COSMO: a new approach to dielectric screening in solvents with

explicit expressions for the screening energy and its gradient. J. Chem. Soc. Perkin Trans. 25,

799–805 (1993).

15. Benisvy, L. et. al. Phenoxyl radicals hydrogen-bonded to imidazolium: Analogues of tyrosyl

D● of Photosystem II: High-Field EPR and DFT studies. Angew. Chem. Int. Ed. 44, 5314–5317

(2005).

16. Orio, M. et. al. Geometric and electronic structures of phenoxyl radicals hydrogen bonded to

neutral and cationic partners. Chem. Eur. J. 18, 5416–5429 (2012).

© 2014 Macmillan Publishers Limited. All rights reserved.

NATURE CHEMISTRY | www.nature.com/naturechemistry 37

SUPPLEMENTARY INFORMATIONDOI: 10.1038/NCHEM.186237

17. Costentin, C., Robert, M., Saveant, J.-M. Electrochemical concerted proton and electron

transfers. Potential-dependent rate constant, reorganization factors, proton tunneling and isotope

effects J. Electroanal. Chem. 588, 197–206 (2006).

18. Savéant, J.-M. Elements of Molecular and Biomolecular Electrochemistry Ch. 1 (Wiley-

Interscience, New York, 2006).

19. Using DigiElch software, see: Rudolph, M. J. Electroanal. Chem. 543, 23–39 (2003).

20. Bruker SAINT-Plus (Bruker AXS Inc., Madison, Wisconsin, USA, 2009).

21. Bruker APEX2, SADABS, (Bruker AXS Inc., Madison, Wisconsin, USA, 2010).

22. Sheldrick, G. M., SHELXS and SHELXL, Acta Cryst. A, 2008, 64, 112–122.

23. Speck, A. L., "PLATON, a multipurpose crystallographic tool." Utrecht University, Utrecht,

The Netherlands, 2001, http://www.cryst.chem.uu.nl/platon/.

24. Bruker XShell ver. 6.3.1, (Bruker AXS Inc., Madison, Wisconsin, USA, 2004).

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