Triplet–Triplet Annihilation-Photon Upconversion Employing an Adamantane-linked Diphenylanthracene Dyad Strategy

Journal Pre-proof Triplet–Triplet Annihilation-Photon Upconversion Employing an Adamantane-linked Diphenylanthracene Dyad Strategy Yasunori Matsui, Masaya Kanoh, Eisuke Ohta, Takuya Ogaki, Hiroshi Ikeda

PII:

S1010-6030(19)31454-6

DOI:

https://doi.org/10.1016/j.jphotochem.2019.112107

Reference:

JPC 112107

To appear in:

Journal of Photochemistry & Photobiology, A: Chemistry

Received Date:

23 August 2019

Revised Date:

24 September 2019

Accepted Date:

25 September 2019

Please cite this article as: Matsui Y, Kanoh M, Ohta E, Ogaki T, Ikeda H, Triplet–Triplet Annihilation-Photon Upconversion Employing an Adamantane-linked Diphenylanthracene Dyad Strategy, Journal of Photochemistry and amp; Photobiology, A: Chemistry (2019), doi: https://doi.org/10.1016/j.jphotochem.2019.112107

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Triplet–Triplet Annihilation-Photon Upconversion Employing an Adamantane-linked Diphenylanthracene Dyad Strategy Yasunori Matsui,[a,b] Masaya Kanoh,[a] Eisuke Ohta,[a,b] Takuya Ogaki,[a] and Hiroshi Ikeda*[a,b] a

Department of Applied Chemistry, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan, E-mail: [email protected] b

The Research Institute for Molecular Electronic Devices (RIMED), Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan

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Graphical Abstract

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Leave this area blank for abstract info.

Highlights

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• An adamantane-linked diphenylanthracene dyad, DPA–Ad–DPA, was newly synthesized. • Photon-upconversion (UC) luminescence was observed for DPA–Ad–DPA due to the progress of triplet–

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triplet annihilation (TTA).

• A dyad strategy using two-conjugated acceptors and a non--conjugated linker has the potential for improving UC efficiency by employing both intermolecular and intramolecular TTA.

Abstract: A triplet–triplet annihilation (TTA) upconversion (UC) was examined by using a dyad, DPA–Ad–DPA, composed of two 9,10-diphenylanthracene (DPA) moieties linked by an adamantane (Ad) backbone. This acceptor-dyad strategy has the potential of improving the efficiency of TTA-UC, based on maintaining intrinsic singlet and triplet energy levels and controlling the multiexcitonic states in TTA.

Keywords: Photon Upconversion, Triplet–Triplet Annihilation, Dyad, Delayed Fluorescence

Introduction

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Photon upconversion (UC) is a phenomenon in which a high-energy photon is generated from two low-energy photons.1,2 Although multiphoton absorption3,4 and high harmonic generation5,6 are phenomena that lead to UC, the promotion of both processes suffers from a serious drawback associated with the requirement for extremely high light intensities (~106 mWcm–2). From this perspective, triplet–triplet annihilation (TTA)-assisted UC (TTAUC),7–9 which can be initiated using even relatively non-intense sunlight (~1 mW cm–2), has attracted much

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attention. The exergonic mechanism for TTA-UC of two energy donors (D) and two energy acceptors (A), illustrated in Fig. 1, involves the following key steps, (i) excitation of D followed by intersystem crossing (ISC) to give 3D*, (ii) energy transfer (ET) from 3D* to A, (iii) TTA of two 3A* to form 1A* and A, and (iv) fluorescence

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emission from 1A*. The use of UC to obtain a high-energy photon from two low-energy photons requires that the energy gaps between the lowest singlet (S1) and triplet (T1) states of D and A be different. Conventional protocols for development of systems that display efficient TTA-UC have focused on increasing the efficiencies of ISC and

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ET from 3D* to A, and increasing the lifetime of 3A* (T) and FL of 1A*.10–12 For instance, it has been shown that a degassed solution of platinum (II) octaethylporphyrin (PtOEP) and 9,10-diphenylanthracene (DPA) has a quantum yield for TTA-UC (UC) up to 0.26.8 The most important key primary process that determines overall

A

A

hn536

hn536

A

A

3D* 3D*

3A* 3A*

D

ET

EX

D

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ISC

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Relative Energy

1D* 1D*

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efficiency of TTA-UC is TTA, because the probability of association of two 3A* is quite limited.

A D

A D

TTA

A D

hn435

1A*

D

FL

Reaction coordinate

Fig. 1. Energy diagram for the exergonic TTA-UC system using two Ds and two As.

Construction of a dyad, A–L–A, composed of two As and a linker (L) is an effective strategy to control orientation, i.e., distance and angle, of two As, avoiding the formation of intramolecular excimer.13 In the dyad system, usual intermolecular and intramolecular TTAs take place competitively (Fig. 2). If the efficiency of intramolecular TTA is higher than usual intermolecular TTA, overall TTA-UC efficiency can be improved.14–21

Furthermore, if a non--conjugated L is employed, it enables A to conserve intrinsic S1 and T1 energy levels. In the study described below, we explored this strategy for improving the efficiency of TTA-UC by designing the new dyad, DPA–Ad–DPA (Chart 1), composed of two DPA moieties attached to the C1 and C3 positions of an adamantane (Ad) linker. An Ad linker, known as the smallest unit of diamond, works as a rigid and nonconjugated linker that fixes two As in 109º. The resulting structural constraints imposed on the DPA moieties should fix the orientation of two As. The results of the current effort, which focuses on the preparation and spectroscopic studies of DPA–Ad–DPA in solutions, have provided interesting information about the mechanism for competitive intermolecular and intramolecular TTA-UC.

L

Relative Energy

* 3A A

L

A

A

3A*

3A*

Energy Transfer L

Association

L

A

3A*

A

intramolecular TTA

3A*

A

L

3A*

L

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L

A A

L

A

1 A*

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intermolecular TTA Reaction Coordinate

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Fig. 2. Schematic representation of overall TTA process of two A–L–3A*, distinguishing intermolecular and

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intramolecular TTAs in solution.

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Chart 1. Structures of DPA–Ad–DPA, tBu–DPA, and PtOEP.

Results and Discussion

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The dyad, DPA–Ad–DPA, was synthesized by using Suzuki–Miyaura coupling22 reaction of 123–27 with boronic acid 2 (Scheme 1). Recrystallization from benzene (or THF) afforded DPA–Ad–DPA as a 1:1 co-crystal with a solvent molecule. The chromophore related model compound, tBu–DPA, was also synthesized. The results of preliminary X-ray crystallographic analysis28 and density functional theory (DFT) calculations 23,29 of DPA–Ad– DPA (Fig. 3) show that the distance between the C9 positions of the DPA moieties in DPA–Ad–DPA are 12.1 and 12.3 Å, respectively, which is slightly longer to promote TTA via electron-exchange.12 The presence of the rigid Ad linkage in DPA–Ad–DPA should hinder the formation of an intramolecular excimer. Interestingly, in the crystalline state, the anthracene moieties in DPA–Ad–DPA adopt an almost coplanar configuration, probably as a result of limitations imposed by crystal packing (Fig. 3a).

Scheme 1. Synthetic route for DPA–Ad–DPA.

(a)

(b)

12.1 Å

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2.3 Å 12.3 Å

Fig. 3. Geometries of DPA–Ad–DPA obtained by (a) X-ray crystallographic analysis and (b) DFT calculation (B3LYP/6-311G*).

A degassed benzene solution of DPA–Ad–DPA displayed an absorption band at 376 nm (Fig. 4a, red). Excitation of the solution by using 376-nm light led to intense fluorescence with a wavelength maximum at 416

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nm (Fig. 4b, red, Table 1), a quantum yield (FL) of 0.74 and a lifetime (FL) of 4.7 ns. The structurally-related compound, tBu–DPA, displayed similar 376-nm absorption and 416-nm fluorescence bands (FL = 0.72, FL = 4.9 ns, Figs. 4a and b, blue). The nearly identical fluorescence properties of DPA–Ad–DPA and tBu–DPA suggest

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that interaction between two DPA moieties in DPA–Ad–DPA leading to intramolecular excimer formation did not take place. The results of DFT calculations (B3LYP/6-311G*) show that the frontier molecular orbitals of DPA–

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Ad–DPA are localized on each DPA moiety, being consistent with monomeric fluorescence properties of DPA– Ad–DPA. Importantly, the requirement for exclusive excitation of PtOEP with 536-nm light in the presence of

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DPA–Ad–DPA is possible because the latter substance does not absorb at this wavelength.

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Fig. 4. (a) UV–vis absorption and (b) photoluminescence spectra of DPA–Ad–DPA (red), tBu–DPA (blue), and PtOEP (green).

Table 1. Photophysical Parameters of DPA–Ad– DPA and tBu–DPA[a] Compound DPA–Ad–DPA t

Bu–DPA

AB / nm

FL / nm

FL

FL / ns

376

416

0.74

4.7

376

416

0.72

4.9

[a] Measured in CH2Cl2.

Rate constants for ET from

3PtOEP*

to DPA–Ad–DPA and

tBu–DPA

were assessed by using

phosphorescence quenching experiments. The phosphorescence lifetime of PtOEP in degassed benzene without DPA–Ad–DPA and tBu–DPA was determined to be 24.7 s (PH0). When DPA–Ad–DPA or tBu–DPA was added to the solution, the phosphorescence lifetime of PtOEP (PH) decreased in a concentration dependent manner. Analysis of the corresponding Stern–Volmer type plots of the quenching data, showed that the respective rate constants for ET (kET) from 3PtOEP* to DPA–Ad–DPA and tBu–DPA are 0.22 × 1010 and 0.16 × 1010 M–1s–1, respectively, matching expectations based on their relative triplet energies (T 1 energy levels of PtOEP and DPA are 1.96 and 1.77 eV, respectively). These values are almost 1/8 of the diffusion controlled rate constant in degassed benzene, suggesting that ET takes place efficiently in both cases.

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Excitation of a degassed benzene solution of DPA–Ad–DPA (0.5 mM) and PtOEP (0.05 mM) using 520-nm light afforded UC luminescence at 435 nm (Fig. 5a, red). When tBu–DPA (0.65 mM) was employed in place of DPA–Ad–DPA, similar but slightly intense UC luminescence was observed (Fig. 5a, blue). Therefore, the results suggest that the TTA-UC efficiency in the PtOEP / DPA–Ad–DPA system is lower than expected. To gain quantitative insights into TTA-UC of DPA–Ad–DPA and tBu–DPA, the dependence of UC luminescence (IUC) on

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excitation intensity (IEX) was examined. In this experiment, quantum yields for ET (ET) from 3PtOEP* to DPA– Ad–DPA and tBu–DPA were adjusted to be ET = 0.98 by controlling the concentration of the latter substances

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([DPA–Ad–DPA] = 0.5 mM, or [tBu–DPA] = 0.65 mM for [PtOEP] = 0.05 mM). Note that because a dyad has larger kET compared with the corresponding monomer as described above, the threshold intensity (ITH), an index for low excitation intensity, should be evaluated under the conditions of the same ET. In our measurement, the

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region of slope ~ 1 was observed for tBu–DPA (Fig. 5b, blue), but was not observed for DPA–Ad–DPA (Fig. 5b, red). In the latter, as increasing IEX, the slope that was ca. 2 (at IEX < 30 mWcm–2) gradually decreased to ca. 1 (at IEX = 30–50 mWcm–2), but then slightly increased (at IEX > 50 mWcm–2). Thus, we employed recently developed

𝐼TH = 𝐾𝐼EX [1 +

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fitting function (eqn 1)30, developed by Kamada and co-workers, for simple intermolecular TTA systems, 1−√1+4𝐼EX ⁄𝐼TH 2𝐼EX ⁄𝐼TH

]

(1)

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where K is proportional constant, afforded preliminary ITH, to be 25 and 20 mWcm –2 for DPA–Ad–DPA and tBu– DPA, respectively. Namely, a slightly larger ITH value was obtained for PtOEP/DPA–Ad–DPA system compared with PtOEP/tBu–DPA system though there may be a complicated relationship between IEX and ITH in the dyad

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system. Note that ITH is related to the rate constant for decay of 3A* (kT), ET and kTTA, through the relationship shown in eqn 2.8,31

ITH  kT2/ETkTTA

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In this analysis, the difference in ITH should be explained by only difference in kT and/or kTTA, because ET was adjusted to 0.98 for both systems. Dyads often possess a small kT compared with the corresponding monomer,32,33 thus low ITH is expected. However, a slightly larger ITH was observed for DPA–Ad–DPA. This result can be explained by decrease of the selectivity of the S1 state in TTA of the DPA–Ad–DPA dyad. Note that the ratio for formation of the singlet : triplet : quintet states in TTA is 1 : 3 : 5 according to the spin-statistics.34 Thus, the selectivity of the S1 state should be 1/9. However, the selectivity of the S1 state in TTA is affected by solvent

reported by Murakami35 and Ikoma.36 Although a creation of dyad generally imposes free molecular orientational change between two As, a well-designed orientation in dyad must improve the selectivity of the S1 state in the intramolecular TTA.

hn

532 nm

ET

435 nm

300

500

700

lUC / nm

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Int. / a.u.

(a)

(b) 20 mWcm–2

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1

IUC / a.u.

25 mWcm–2 2 20

30 40 50

100

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10

IEX / mWcm–2

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Fig. 5. (a) UC fluorescence spectra (IEX = 30 mWcm–2) and (b) double-logarithmic plots and fitted curves of IUC@435 nm against IEX upon 520-nm excitation of a degassed benzene solution of DPA–Ad–DPA (red, 0.5 mM) or tBu–DPA (blue, 0.65 mM) containing PtOEP (0.05 mM).23 Photo: TTA-UC luminescence of a benzene solution

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of DPA–Ad–DPA and PtOEP observed upon at 532-nm excitation.

Mechanistic analysis for intermolecular and intramolecular TTA via DPA–Ad–3DPA* and 3DPA*–Ad–3DPA*, respectively, is informative for understanding our dyad system. Classic steady-state approximation is a powerful

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tool to evaluate concentration of the excited species. According to the treatment by Castellano9 with appropriate parameters (1.0 mW CW laser, 2mm, kT = 4.0 × 102 s–1 for DPA–Ad–DPA, the same as DPA37), [3PtOEP*] and [DPA–Ad–3DPA*] are estimated to be 7  10–11 and 3.0 × 10–7 M, respectively.23 The value of [DPA–Ad–3DPA*] is

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ramolecular TTA

viscosity. A high solvent viscosity probably leads to prevention of change of free relative orientation of two As, as

nearly 1,000 times lower than that of [DPA–Ad–DPA]. Therefore, ET from 3PtOEP* to DPA–Ad–DPA takes place nearly 1,000 times faster than to DPA–Ad–3DPA*. Thus, the most probable process for the formation of 3DPA*– Ad–3DPA* would be an intermolecular ET reaction between two DPA–Ad–3DPA* (eqn 3 and Fig. 2 as a general illustration). 2 DPA–Ad–3DPA* → 3DPA*–Ad–3DPA* + DPA–Ad–DPA

(3)

Although the multiexcitonic state 3DPA*–Ad–3DPA* was not observed directly, but are inevitable intermediate when considering intramolecular TTA. Many efforts have been made to control multiexcitonic state in the field of intramolecular singlet fission (SF), which is the reverse of TTA, and

have provided excellent dyads that exhibit high rate constant for SF (kSF).38–41 If a dyad possesses 10 times faster kTTA than monomer in the field of intramolecular TTA, the ITH value should be reduced to 1/10 (eqn 2) in the solid state where rapid energy migration takes place.30,42 Therefore, a dyad diluted in a host monomer material must work effectively. Such a well-designed dyad can convert triplet excitons to singlet ones via TTA, acting as a ‘molecular hot spot’.43

Conclusion In conclusion, we investigated the TTA-UC process taking place in the new dyad, DPA–Ad–DPA, in which two DPA moieties are linked by an Ad unit. The results of preliminary spectroscopic studies revealed that two DPA moieties in DPA–Ad–DPA do not observably interact in the S0 and S1 states. The essential index of efficiency of TTA-UC, ITH, for DPA–Ad–DPA is slightly higher compared with the corresponding monomer tBu–DPA. This

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result is attributable to decrease of selectivity of the S1 state in TTA, probably due to progress of intramolecular TTA.

Our dyad strategy using A–L–A, i.e. a control of appropriate orientation of two A units, certainly contribute in creation of an efficient TTA-UC material. A non--conjugated and rigid linker L is effective to prevent complicated orbital interaction between two -conjugated A units and to control the multiexcitonic states44 that serve as key

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species not only for TTA but probably also for SF.33,45,46 Further effort using other dyads in this line is in progress

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and results will be published elsewhere.

Acknowledgements

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The authors acknowledge valuable discussion with Dr. Kenji Kamada (National Institute of Advanced Industrial Science and Technology) related to determination of ITH using fitting functions. This work was partially supported by JSPS KAKENHI Grant (Nos. JP24109009, JP23350023, 19H00888, JP18H01967, JP18K14202, JP17H01265). YM was also supported by the Program to Disseminate Tenure Tracking System, MEXT, Japan

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and Sasakawa Scientific Research Grant from the Japan Science Society (29-303).

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Experimental Section Preparation of Substrates

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A Complex of 1,3-Bis(4-phenylanthracen-9-yl)phenyl)adamantane with Benzene (DPA–Ad–DPA•C6H6): 1,3Bis(4-bromophenyl)adamantane (1, 535 mg, 1.2 mmol, Scheme 1), 10-phenyl-9-anthracene boronic acid (2, 858 mg, 2.8 mmol), and tetrakis(triphenylphosphine)palladium (130 mg, 0.12 mmol) were added in a 100 mL threenecked flask under argon. The mixture of Na2CO3 (4.24 g, 40 mmol), toluene (20 mL), ethanol (4 mL), and water (20 mL) was added to the flask, and stirred under reflux condition for 26 h. After the reaction, the mixture was quenched by water and extracted with CHCl3 (30 mL × 5). The combined organic extracts were washed with brine, dried over NaSO4 and filtered. The filtrate was evaporated to dryness under a reduced pressure. The residue was subjected to column chromatography on SiO 2 (CHCl3). Recrystallization from benzene allowed a complex of DPA–Ad–DPA•C6H6 as colorless powder (574 mg, 0.65 mmol) in 55% yield. Colorless powder; mp > 300 °C (from benzene); 1H NMR (300 MHz, CDCl3) δppm 1.95 (br t, 2H), 2.23 (m, 8H), 2.38 (s, 2H), 2.51 (br, 2H),

7.32–7.36 (m, 8H), 7.36 (s, 6H, C6H6), 7.46–7.50 (m, 8H), 7.55–7.71 (m, 17H), 7.75–7.78 (m, 4H);

13C

NMR (75

MHz, CDCl3) δppm 29.35 (2C), 36.08 (C), 37.51 (2C), 42.47 (4C), 49.78 (C), 124.88 (4C), 124.98 (4C), 126.92 (4C), 127.17 (4C), 127.43 (2C), 128.34 (4C), 128.40 (4C), 129.90 (4C), 130.02 (4C), 131.14 (4C), 131.35 (4C), 136.24 (2C), 136.91 (2C), 137.31 (2C), 139.16 (2C), 149.86 (2C); FAB-mass m/z 792 ([M]+ for C62H48); Anal. Calcd. for C62H48•C6H6: C 93.75, H 6.25, Found: C 92.92, H 6.20. 9-(4-(tert-Butyl)phenyl)-10-phenylanthracene (tBu–DPA): 4-tert-Butylbromobenzene (60 mg, 0.3 mmol), 2 (100 mg, 0.36 mmol), and tetrakis(triphenylphosphine)palladium(0) (17 mg, 0.015 mmol) were added in a 100 mL three-necked flask under argon. The mixture of Na2CO3 (1.06 g, 10 mmol), toluene (5 mL), ethanol (1 mL) and water (50 mL) was added to the flask and refluxed for 20 h. After reaction, the mixture was quenched by water and extracted with CHCl3 (30 mL × 3). The combined organic extracts were washed with brine, dried over Na2SO4, and evaporated to dryness under a reduced pressure. The residual mixture was subjected to column

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chromatography on SiO2 (CHCl3). Recrystallization from CHCl3–ethanol allowed isolation of tBu–DPA as colorless powder (96 mg, 0.25 mmol) in 83% yield. Colorless powder; mp 274–275 °C; 1H NMR (300 MHz, CDCl3) δppm 1.47 (s, 9H), 7.30 (m, 4H), 7.39 (d, 2H), 7.47 (d, 2H), 7.51–7.61 (m, 5H), 7.67 (m, 2H), 7.73 (m, 2H); 13C

NMR (75 MHz, CDCl3) δppm 31.76 (3C), 34.96, 125.03 (2C), 125.15 (2C), 125.44 (2C), 125.49 (2C), 127.12

(2C), 127.38 (2C), 127.61 (2C), 128.58, 130.14 (2C), 130.27 (2C), 131.16 (2C), 131.57 (2C), 136.10 (2C), 137.09

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(2C), 137.57 (2C), 139.43 (2C), 150.51; FAB-mass m/z 386 ([M]+ for C30H26).

Measurement of UC Luminescence. UC luminescence observation was carried out using Ocean Optics

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USB4000 multichannel detector upon CW-laser (RGB Photonics, Minilas Fiber, 520 nm) excitation. The sample solutions in J.Young valve-fused quartz vessels were degassed with three freeze (77 K)–pump (0.1 mmHg)–thaw

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(ambient temperature) cycles and then sealed before the experiments.

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Conflict of interests The authors declare no conflict of interests.

References and Notes (2) (3) (4)

Zhou, J.; Liu, Q.; Feng, W.; Sun, Y.; Li, F. Chem. Rev. 2015, 115, 395–465.

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(1)

Ye, C.; Zhou, L.; Wang, X.; Liang, Z. Phys. Chem. Chem. Phys. 2016, 18, 10818–10835. He, G. S.; Tan, L.-S.; Zheng, Q.; Prasad, P. N. Chem. Rev. 2008, 108, 1245–1330. Zhou, B.; Shi, B.; Jin, D.; Liu, X. Nat. Nanotechnol. 2015, 10, 924–936.

(5)

Franken, P. A.; Hill, A. E.; Peters, C. W.; Weinreich, G. Phys. Rev. Lett. 2002, 7, 118–119.

(6)

Aouani, H.; Rahmani, M.; Navarro-Cía, M.; Maier, S. A. Nat. Nanotechnol. 2014, 9, 290–294.

(7)

Singh-Rachford, T. N.; Castellano, F. N. Coord. Chem. Rev. 2010, 254, 2560–2573.

(8)

Monguzzi, A.; Tubino, R.; Hoseinkhani, S.; Campione, M.; Meinardi, F. Phys. Chem. Chem. Phys. 2012, 14, 4322–4332.

(9)

Schmidt, T. W.; Castellano, F. N. J. Phys. Chem. Lett. 2014, 5, 4062–4072.

(10)

Duan, P.; Yanai, N.; Nagatomi, H.; Kimizuka, N. J. Am. Chem. Soc. 2015, 137, 1887–1894.

(11)

Duan, P.; Yanai, N.; Kurashige, Y.; Kimizuka, N. Angew. Chem. Int. Ed. 2015, 54, 7544–7549.

(12)

Sato, R.; Kitoh-Nishioka, H.; Kamada, K.; Mizokuro, T.; Kobayashi, K.; Shigeta, Y. J. Phys. Chem. C 2018, 122, 5334–5340.

(13)

Ye, C.; Gray, V.; Mårtensson, J.; Börjesson, K. J. Am. Chem. Soc. 2019, 141, 9578–9584.

(14)

Pun, A. B.; Sanders, S. N.; Sfeir, M. Y.; Campos, L. M.; Congreve, D. N. Chem. Sci. 2019, 10, 3969–3975.

(15)

Dzebo, D.; Börjesson, K.; Gray, V.; Moth-Poulsen, K.; Albinsson, B. J. Phys. Chem. C 2016, 120, 23397– 23406. Wu, W.; Liu, L.; Cui, X.; Zhang, C.; Zhao, J. Dalton Trans. 2013, 42, 14374–14379.

(17)

Ribas, M. R.; Steer, R. P.; Rüther, R. Chem. Phys. Lett. 2014, 605–606, 126–130.

(18)

Ji, S.; Wu, W.; Zhao, J.; Guo, H.; Wu, W. Eur. J. Inorg. Chem. 2012, 2012, 3183–3190.

(19)

Tilley, A. J.; Robotham, B. E.; Steer, R. P.; Ghiggino, K. P. Chem. Phys. Lett. 2015, 618, 198–202.

(20)

Gray, V.; Küçüköz, B.; Edhborg, F.; Abrahamsson, M.; Moth-Poulsen, K.; Albinsson, B. Phys. Chem. Chem. Phys. 2018, 20, 7549–7558.

ro of

(16)

Gray, V.; Moth-Poulsen, K.; Albinsson, B.; Abrahamsson, M. Coord. Chem. Rev. 2018, 362, 54–71.

(22)

Miyaura, N.; Suzuki, A. Chem. Rev. 1995, 95, 2457–2483.

(23)

For the detail, see the Supporting Information.

(24)

Senchyk, G. A.; Lysenko, A. B.; Boldog, I.; Rusanov, E. B.; Chernega, A. N.; Krautscheid, H.; Domasevitch, K. V. Dalton Trans. 2012, 41, 8675–8689.

Degtyarenko, A. S.; Handke, M.; Krämer, K. W.; Liu, S. X.; Decurtins, S.; Rusanov, E. B.; Thompson, L.

re

(25)

-p

(21)

K.; Krautscheid, H.; Domasevitch, K. V. Dalton Trans. 2014, 43, 8530–8542. Zhu, X.; Shao, B.; Vanden Bout, D. A.; Plunkett, K. N. Macromolecules 2016, 49, 3838–3844.

(27)

Mosset, P.; Grée, R. Synlett 2013, 24, 1142–1146.

(28)

Sheldrick, G. M. Acta Crystallogr. Sect. C, Struct. Chem. 2015, 71, 3–8.

(29)

Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani,

lP

(26)

na

G.; Barone, V.; Mennucci, B.; Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H. P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, J. A., J.;

ur

Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin, K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega, N.; Millam, N. J.; Klene, M.; Knox, J. E. Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.;

Jo

Gomperts, R.; Stratmann, R. E.; Yazyev, O. .; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.; Morokuma, K. .; Zakrzewski, V. G.; Voth, G. A.; Salvador, P. .; Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, Ö.; Foresman, J. B.; Ortiz, J. V.; Cioslowski, J.; Fox, D. J. Gaussian 09, Revision D.01, 2009.

(30)

Kamada, K.; Sakagami, Y.; Mizokuro, T.; Fujiwara, Y.; Kobayashi, K.; Narushima, K.; Hirata, S.; Vacha, M. Mater. Horizons 2017, 4, 83–87.

(31)

Monguzzi, A.; Mezyk, J.; Scotognella, F.; Tubino, R.; Meinardi, F. Phys. Rev. B 2008, 78, 195112.

(32)

Sakuma, T.; Sakai, H.; Araki, Y.; Mori, T.; Wada, T.; Tkachenko, N. V.; Hasobe, T. J. Phys. Chem. A 2016, 120, 1867–1875.

(33)

Matsui, Y.; Kawaoka, S.; Nagashima, H.; Nakagawa, T.; Okamura, N.; Ogaki, T.; Ohta, E.; Akimoto, S.; Sato-Tomita, A.; Yagi, S.; Kobori, Y.; Ikeda, H. J. Phys. Chem. C 2019, 123, 18813–18823.

(34)

Turro, N. J.; Ramamurthy, V.; Scaiano, J. C. Principles of Molecular Photochemistry: An Introduction; University Science Books, 2009.

(35)

Murakami, Y.; Kikuchi, H.; Kawai, A. J. Phys. Chem. B 2013, 117, 5180–5187.

(36)

Yokoyama, K.; Wakikawa, Y.; Miura, T.; Fujimori, J. I.; Ito, F.; Ikoma, T. J. Phys. Chem. B 2015, 119, 15901–15908.

(37)

Wayne, R. P. Handbook of photochemistry (second edition); Marcel Dekker: New York, 2002; Vol. 78.

(38)

Basel, B. S.; Zirzlmeier, J.; Hetzer, C.; Phelan, B. T.; Krzyaniak, M. D.; Reddy, S. R.; Coto, P. B.; Horwitz, N. E.; Young, R. M.; White, F. J.; Hampel, F.; Clark, T.; Thoss, M.; Tykwinski, R. R.; Wasielewski, M. R.; Guldi, D. M. Nat. Commun. 2017, 8, 15171. Zirzlmeier, J.; Lehnherr, D.; Coto, P. B.; Chernick, E. T.; Casillas, R.; Basel, B. S.; Thoss, M.; Tykwinski, R. R.; Guldi, D. M. Proc. Natl. Acad. Sci. 2015, 112, 5325–5330.

ro of

(39)

(40)

Hetzer, C.; Guldi, D. M.; Tykwinski, R. R. Chem. Eur. J. 2018, 24, 8245–8257.

(41)

Gilligan, A. T.; Miller, E. G.; Sammakia, T.; Damrauer, N. H. J. Am. Chem. Soc. 2019, 141, 5961–5971.

(42)

Narushima, K.; Hirata, S.; Vacha, M. Nanoscale 2017, 9, 10653–10661.

(43)

Nagashima, H.; Kawaoka, S.; Akimoto, S.; Tachikawa, T.; Matsui, Y.; Ikeda, H.; Kobori, Y. J. Phys. Chem.

-p

Lett. 2018, 9, 5855–5861.

Miyata, K.; Conrad-Burton, F. S.; Geyer, F. L.; Zhu, X.-Y. Chem. Rev. 2019, 119, 4261–4292.

(45)

Smith, M. B.; Michl, J. Chem. Rev. 2010, 110, 6891–6936.

(46)

Hetzer, C.; Basel, B. S.; Kopp, S. M.; Hampel, F.; White, F. J.; Clark, T.; Guldi, D. M.; Tykwinski, R. R.

re

(44)

Jo

ur

na

lP

Angew. Chem. Int. Ed. in press, DOI: 10.1002/anie.201907221.