www.sciencemag.org/content/363/6427/601/suppl/DC1

Supplementary Materials for Eliminating nonradiative decay in Cu(I) emitters: >99% quantum efficiency

and microsecond lifetime

Rasha Hamze, Jesse L. Peltier, Daniel Sylvinson, Moonchul Jung, Jose Cardenas, Ralf Haiges, Michele Soleilhavoup, Rodolphe Jazzar, Peter I. Djurovich, Guy Bertrand, Mark E. Thompson*

*Corresponding author. Email: met@usc.edu

Published 8 February 2019, Science 363, 601 (2019)

DOI: 10.1126/science.aav2865

This PDF file includes:

Materials and Methods Figs. S1 to S61 Tables S1 to S22 References

Contents

General Information ...................................................................................................................................... 3 

Synthesis ........................................................................................................................................................ 5 

Crystallographic data ................................................................................................................................... 10 

Electrochemical characterization ................................................................................................................ 21 

Density Functional Theory Calculations ...................................................................................................... 23 

Photophysical characterization ................................................................................................................... 25 

OLED fabrication and characterization ....................................................................................................... 42 

Time dependent DFT (TDDFT) and Molecular Dynamics ............................................................................ 52 

NMR Spectra ............................................................................................................................................... 57 

References .................................................................................................................................................. 68 

2

General Information 

Synthesis. All reactions were performed under nitrogen atmosphere in oven dried glassware.

Carbazole (Cz), diphenylamide (NPh2), and polystyrene beads (PS, average Mw ~ 192,000) were

purchased from Sigma-Aldrich. 3,5-dimethoxy-9-H-carbazole (CzOMe) was purchased from Ark

Pharm. 3,5-dicyano-9-H-carbazole (CzCN)(53) and 1,8-dimethyl-9-H-carbazole (MeCz)(54) were

prepared following literature procedures. CAAC-CuCl precursors and complex 1b(19) were

synthesized following published reports.(55-58) Dry, air-free methylcyclohexane (MeCy) and

2-methyltetrahydrofuran (2-MeTHF) were purchased from Sigma-Aldrich. MeCy was used

without further purification. Dichloromethane (CH2Cl2), and toluene (tol.) were purified by Glass

Contour solvent system by SG Water USA, LLC. Tetrahydrofuran (THF) and 2-MeTHF were

distilled over Na/benzophenone under N2 atmosphere for use with complexes 2b and 5 that are

ultrasensitive to trace moisture. Drisolv acetonitrile (AcN) and dimethylformamide (DMF) were

purchased from EMD Millipore. 1H and 13C NMR spectra were recorded on a Varian Mercury 400,

a Bruker Advance 300 (complex 2b), and a Varian Inova 500 (Cu host). 19F NMR spectrum for

complex “Cu host” was recorded on a Bruker Avance 300 MHz. The chemical shifts are given in

units of ppm and referenced to the residual proton resonances of acetone ((CD3)2CO) at 2.05 ppm,

chloroform (CDCl3) at 7.26 ppm., or dichloromethane CD2Cl2 at 5.32 ppm. Elemental analyses

were performed at the University of Southern California, CA. 

DFT/TDDFT Calculations and Molecular Dynamics. All DFT and TDDFT calculations

reported in this work were performed using the Q-Chem 5.0 package.(59) Geometry optimization

for all complexes was performed at the B3LYP/LACVP** level. Single point TDDFT calculations

were performed on the ground state optimized structures at the CAM-B3LYP/LACVP** level to

compute excited state properties. The electrostatic potential-fitted (esp) atomic charges for 2-

MeTHF and complex 1a used to replace the partial charges of the OPLS2005 forcefield for the

MD simulations, were computed at the B3LYP/6-31G** and ωPBEh(= 0.263 bohr-1) /6-31G**

levels respectively. The esp charges of the triplet (3ICT) state of 1a was computed using the

unrestricted DFT scheme (UDFT). TDDFT calculations on the solvated clusters derived from the

snapshots of the MD simulations were performed at the ωPBEh(= 0.263 bohr-1) /6-31G** level

by replacing the atoms of all solvent molecules with their corresponding esp charges to act as a

polarizing influence on the complex. The value of the range separation parameter () in the ωPBEh

3

functional was tuned to satisfy the global density-dependent (GDD) criterion to get a balanced

description of CT and LE states and in the case of complex 1a, the tuned value was found to be

0.263 bohr-1.(60) All MD simulations reported here were performed using the Desmond program

available within Schrӧdinger’s Materials Science Suite.(61)

Photophysical characterization. The UV-visible spectra were recorded on a Hewlett-

Packard 4853 diode array spectrometer. Steady state emission measurements were performed

using a QuantaMaster Photon Technology International spectrofluoremeter. All reported spectra

are corrected for photomultiplier response. Phosphorescence lifetime measurements were

performed using an IBH Fluorocube instrument equipped with 331 nm LED and 405 nm laser

excitation sources using time-correlated single photon counting method. Long-lived

phosphorescence decays (> 30 μs) were measured using a QuantaMaster Photon Technology

International spectrofluoremeter equipped with a Xe flash lamp. Quantum yields at room

temperature were measured using a Hamamatsu C9920 system equipped with a xenon lamp,

calibrated integrating sphere and model C10027 photonic multichannel analyzer (PMA). All

samples were deaerated by bubbling N2 in a glass cuvette fitted with a Teflon stopcock. Samples

of complexes 2b and 5 were prepared under N2 in an air-tight Schlenk flask connected to a quartz

cuvette via a glass bridge.

XRay Crystallography. The single-crystal X-ray diffraction data for compounds 1a, 1c, 1d,

and 3 – 5 were collected on a Bruker SMART APEX DUO three-circle platform diffractometer

with the χ axis fixed at 54.745° and using Mo Kα radiation (λ = 0.710 73 Å) monochromated by a

TRIUMPH curved-crystal monochromator. The crystals were mounted in Cryo-Loops using

Paratone oil. Data were corrected for absorption effects using the multiscan method (SADABS).

The structures were solved by direct methods and refined on F2 using the Bruker SHELXTL

software package. All non-hydrogen atoms were refined anisotropically. The single crystal X-ray

diffraction study for 2b was carried out on a Bruker D8 diffractometer equipped with a Dectris

Eiger R 1M HPAD detector and Cu Ka radiation (l = 1.5478). For Cu host, X-ray diffraction

analysis was carried out on a Bruker Kappa APEX-II CCD diffractometer equipped with Mo Ka

radiation (l = 0.71073 Å). In both complexes, crystals were selected under Fomblin oil, mounted

on a Cryoloop, and then immediately placed in a cold stream of nitrogen. The data was integrated

using the Bruker SAINT software program and scaled using the SADABS software program.

4

Solution by direct methods (SHELXT) produced a complete phasing model consistent with the

proposed structure. The structure was refined with SHELXL using Olex2 software. All

nonhydrogen atoms were refined anisotropically by full-matrix least-squares (SHELXL). All

hydrogen atoms were placed using a riding model. Their positions were constrained relative to

their parent atom using the appropriate HFIX command in SHELXL.

Synthesis 

General procedure. CAAC-CuCl, carbazole ligand, and sodium or potassium tert-butoxide

(NaOtBu or KOtBu)) were dissolved in THF and stirred for overnight at RT. The resulting mixture

was filtered through Celite and the solvent was removed under reduced pressure to afford a solid.

The solid was washed copiously with cold pentane and filtered. The filtrate was dried under

vacuum for 24 h.

CAACMen-CuCz (1a). The complex was prepared from CAACMen-CuCl (200 mg,

0.42 mmol), Cz (73 mg, 0.44 mmol) and NaOtBu (42 mg, 0.44 mmol) and isolated as a yellowish

microcystalline solid. Yield: 228 mg (90%). Crystals suitable for an X-ray diffraction study were

grown from a saturated solution of CH2Cl2 layered with pentane. Tsublimation = 250 °C at 2 x 10-6

Torr. 1H NMR (400 MHz, Chloroform-d) 1H NMR (400 MHz, Chloroform-d) δ 7.96 (d, J = 7.7

Hz, 2H), 7.68 (t, J = 8.5 Hz, 1H), 7.46 (dd, J = 16.2, 7.8 Hz, 2H), 7.05 (t, J = 7.6 Hz, 2H), 6.92 (t,

J = 7.7 Hz, 2H), 6.42 (d, J = 8.2 Hz, 2H), 3.19 – 2.86 (m, 5H), 2.41 (d, J = 13.5 Hz, 2H), 2.19 –

1.96 (m, 4H), 1.87 (d, J = 14.4 Hz, 1H), 1.51 (dd, J = 26.1, 2.5 Hz, 11H), 1.34 (t, J = 7.2 Hz, 7H),

1.16 (dd, J = 14.5, 6.1 Hz, 6H), 1.07 (t, J = 6.0 Hz, 6H), 0.93 (d, J = 6.4 Hz, 3H). 13C NMR (101

MHz, CDCl3) δ 252.22, 150.14, 146.51, 146.03, 136.26, 129.73, 125.57, 125.49, 124.48, 123.22,

119.39, 115.26, 114.45, 77.91, 65.73, 35.99, 31.60, 30.10, 29.76, 29.59, 29.41, 28.00, 27.64, 26.44,

5

25.63, 24.43, 23.12, 22.95, 22.86, 19.90. Elemental Analysis: Anal. Cacld. for C39H51CuN2: C,

76.62%; H, 8.41%; N, 4.58%. Found: C, 76.77%; H, 9.26%; N, 4.70%.

CAACEt2-CuCz (1c). The complex was prepared from CAACEt2-CuCl (150 mg,

0.36 mmol), carbazole (64 mg, 0.38 mmol) and NaOtBu (37 mg, 0.38 mmol) and isolated as an

off-white microcrystalline solid. Yield: 182 mg (92%). Crystals suitable for an X-ray diffraction

study were grown by slow evaporation of a saturated solution of acetone. 1H NMR (400 MHz,

Chloroform-d) δ 7.97 (d, J = 7.6 Hz, 2H), 7.64 (t, J = 7.8 Hz, 1H), 7.44 (d, J = 7.8 Hz, 2H), 7.09

(t, J = 8.2 Hz, 2H), 6.93 (t, J = 7.3 Hz, 2H), 6.65 (d, J = 8.1 Hz, 2H), 2.98 (hept, J = 6.8 Hz, 3H),

2.20 – 1.92 (m, 7H), 1.34 (d, J = 6.8 Hz, 7H), 1.27 – 1.18 (m, 12H). 13C NMR (101 MHz, CDCl3)

δ 252.56, 149.91, 145.80, 135.45, 129.65, 125.16, 124.29, 123.11, 119.37, 115.18, 114.37, 80.54,

62.59, 43.40, 31.50, 29.34, 26.78, 22.60, 9.77. Elemental Analysis: Anal. Cacld. for C37H43CuN2

+ 2 H2O: C, 70.49%; H, 8.18%; N, 4.84%. Found: C, 70.26%; H, 7.80%; N, 4.84%.

CAACMe2-CuCz (1d). The complex was prepared from CAACMe2-CuCl (250 mg,

0.65 mmol), carbazole (114 mg, 0.68 mmol) and NaOtBu (66 mg, 0.68 mmol) and isolated as a

beige microcystalline solid. Crystals suitable for an X-ray diffraction study were grown by slow

evaporation of a saturated solution of Et2O. Yield: 317 mg (89%).1H NMR (400 MHz,

Chloroform-d) δ 7.92 (d, J = 7.4 Hz, 2H), 7.57 (t, J = 7.8 Hz, 1H), 7.37 (d, J = 7.8 Hz, 2H), 7.04

(t, J = 8.2 Hz, 2H), 6.87 (t, J = 7.7 Hz, 2H), 6.65 (d, J = 8.1 Hz, 2H), 2.88 (hept, J = 6.8 Hz, 2H),

2.10 (s, 2H), 1.60 (s, 6H), 1.40 (s, 6H), 1.28 (d, J = 6.8 Hz, 6H), 1.18 (d, J = 6.7 Hz, 6H). 13C NMR

(101 MHz, CDCl3) δ 250.62, 149.89, 145.75, 134.80, 129.74, 125.13, 124.29, 123.14, 119.40,

115.22, 114.37, 110.55, 81.22, 77.20, 54.25, 49.84, 29.28, 28.89, 26.79, 22.67. Elemental

Analysis: Anal. Cacld. for C32H39CuN2: C, 69.72%; H, 7.08%; N, 5.08%. Found: C, 69.35%; H,

7.08%; N, 4.87%.

6

CAACAd-Cu(Me2Cz) (2b). A mixture of CAACAd-CuCl (250 mg, 0.52mmol), potassium tert-

butoxide (KOtBu, 59 mg, 0.53 mmol), and 1,8-dimethyl-9-H-carbazole (102 mg, 0.52 mmol) was

dissolved in dry THF (15 mL) under an argon atmosphere. After stirring for 3 hours, the volatiles

were removed under vacuum, and the light yellow solid was washed with ether (3x3 mL).

Extraction with toluene (20 mL) followed by washing with pentane (3x3 mL), and subsequent

evaporation of the volatiles afforded the product as a pale yellow powder (311 mg, 93 % yield).

Crystals suitable for an X-ray diffraction study were grown from a saturated solution of THF

layered with TMS2O. 1H NMR (CD2Cl2, 300 MHz): δ = 7.84 (d, J = 7.4 Hz, 2H), 7.42 (t, J = 7.7

Hz, 1H), 7.30 (d, J = 7.7 Hz, 2H), 7.02 (d, J = 7.4 Hz, 2H), 6.89 (t, J = 7.4 Hz, 2H), 3.50 (br d, J

= 12.2 Hz, 2H), 3.06 (sept, J = 6.7 Hz, 2H) 2.56 (s, 6H), 2.34 (s, 2H), 2.10-1.78 (m, 12H), 1.46 (s,

6H), 1.34 (d, J = 6.7, 6H), 1.24 (d, J = 6.7 Hz, 6H); 13C{1H} NMR (CD2Cl2, 76 MHz): δ = 257.4,

149.7, 145.5, 136.6, 129.8, 125.8, 125.2, 124.6, 122.6, 117.2, 115.7, 79.3, 66.5, 47.5, 38.5, 37.7,

36.4, 34.6, 30.3, 29.4, 28.2, 27.5, 26.8, 24.0, 21.1. Elemental Analysis: Anal. Cacld. for

C40H47CuN2 + H2O: C, 75.14%; H, 8.04%; N, 4.38%. Found: C, 74.99%; H, 7.92%; N, 4.04%.

CAACMen-Cu(CN2Cz) (3). The complex was prepared from CAACMen-CuCl (130 mg,

0.27 mmol), CN2Cz (62 mg, 0.28 mmol) and NaOtBu (27 mg, 0.28 mmol) and isolated as a white

solid. Crystals suitable for an X-ray diffraction study were grown by slow evaporation of a

saturated solution of toluene. Yield: 158 mg (88%). 1H NMR (400 MHz, Chloroform-d) δ 8.25 (d,

J = 1.2 Hz, 2H), 7.71 (t, J = 7.8 Hz, 1H), 7.47 (dd, J = 12.9, 8.5 Hz, 2H), 7.33 (dd, J = 8.5, 1.7 Hz,

2H), 6.36 (d, J = 8.5 Hz, 2H), 3.03 – 2.88 (m, 4H), 2.79 (bs, 1H), 2.43 (d, J = 13.5 Hz, 1H), 2.35

(d, J = 13.2 Hz, 1H), 2.21 – 2.12 (m, 1H), 2.09 – 1.96 (m, 3H), 1.90 (d, J = 13.6 Hz, 1H), 1.61 –

1.46 (m, 10H), 1.36 (t, J = 6.8 Hz, 8H), 1.15 – 1.04 (m, 10H), 1.02 (d, J = 6.9 Hz, 3H), 0.95 (d, J

= 6.4 Hz, 3H). 13C NMR (101 MHz, CDCl3) δ 251.25, 152.76, 146.47, 146.02, 136.29, 129.99,

7

127.94, 125.77, 125.63, 125.04, 123.95, 121.69, 115.34, 99.15, 78.53, 65.74, 52.87, 51.36, 48.43,

35.86, 32.06, 30.14, 29.72, 29.58, 29.40, 27.91, 27.65, 26.47, 25.85, 24.29, 23.03, 22.89, 22.77,

19.84. Elemental Analysis: Anal. Cacld. for C41H49CuN4 + H2O: C, 72.48%; H, 7.57%; N, 8.25%.

Found: C, 72.29%; H, 7.60%; N, 7.91%.

CAACMen-Cu(OMe2Cz) (4). The complex was prepared from CAACMen-CuCl (200 mg,

0.42 mmol), OMe2Cz (95 mg, 0.42 mmol) and NaOtBu (44 mg, 0.46 mmol) and isolated as a

microcrystalline yellow solid; bright green luminescent. Crystals suitable for an X-ray diffraction

study were grown by slow evaporation of a saturated solution of Et2O. Yield: 305 mg (109%) due

to residual THF. The powder was further dried under vacuum for 4 days. 1H NMR (400 MHz,

Chloroform-d) δ 7.65 (t, J = 7.8 Hz, 2H), 7.47 – 7.42 (m, 4H), 7.41 (d, J = 2.6 Hz, 5H), 6.72 (dd,

J = 8.8, 2.6 Hz, 4H), 6.28 (d, J = 8.8 Hz, 4H), 3.88 (s, 11H), 3.13 – 2.90 (m, 5H), 2.39 (d, J = 13.5

Hz, 3H), 2.17 – 1.95 (m, 2H), 1.84 (d, J = 3.8 Hz, 2H), 1.52 (dd, J = 13.7, 4.4 Hz, 4H), 1.46 (d, J

= 4.6 Hz, 14H), 1.38 – 1.28 (m, 10H), 1.15 (dd, J = 15.9, 6.7 Hz, 11H), 1.07 (t, J = 7.3 Hz, 12H),

0.92 (d, J = 6.4 Hz, 6H). 13C NMR (101 MHz, CDCl3) δ 252.22, 151.04, 146.52, 146.02, 136.30,

129.69, 125.58, 125.48, 123.92, 115.20, 113.37, 101.70, 68.12, 65.67, 56.41, 53.00, 51.51, 48.62,

35.98, 31.59, 30.07, 29.71, 29.56, 29.39, 27.97, 27.60, 26.43, 25.76, 25.66, 24.42, 23.09, 22.93,

22.84, 19.88. Elemental Analysis: Anal. Cacld. for C41H55CuN2O2 + H2O: C, 71.43%; H, 8.33%;

N, 4.06%. Found: C, 71.69%; H, 8.69%; N, 4.12%.

CAACMen-Cu(NPh2) (5). The complex was made from CAACMen-CuCl (950 mg,

1.98 mmol), NPh2 (351 mg, 2.08 mmol) and NaOtBu (200 mg, 2.08 mmol) as a bright yellow solid.

Yield: 1.1 g (93%). The complex is exceedingly sensitive to moisture, especially in solution. Single

crystals suited for structural determination were grown by vacuum sublimation, Tsub = 175 °C, P

= 1.8 x 10-6 mTorr. 1H NMR (400 MHz, Chloroform-d) δ 7.56 (t, J = 7.8 Hz, 1H), 7.44 – 7.31 (m,

8

3H), 7.31 – 7.21 (m, 3H), 7.08 (dd, J = 8.6, 1.1 Hz, 1H), 6.94 (dt, J = 7.3, 1.2 Hz, 1H), 6.92 – 6.83

(m, 4H), 6.47 (t, J = 7.2 Hz, 2H), 6.33 (dd, J = 8.5, 1.1 Hz, 3H), 2.98 – 2.78 (m, 4H), 2.68 (dd, J =

13.3, 9.6 Hz, 1H), 2.53 (bs, 1H), 2.34 – 2.20 (m, 3H), 2.13 (d, J = 11.4 Hz, 1H), 1.99 – 1.63 (m,

7H), 1.51 (dd, J = 14.0, 3.5 Hz, 1H), 1.43 – 1.18 (m, 29H), 1.04 (dd, J = 11.2, 6.9 Hz, 4H), 0.94

(d, J = 6.9 Hz, 3H), 0.89 (dd, J = 6.7, 3.1 Hz, 5H), 0.76 (d, J = 6.5 Hz, 3H). 13C NMR (101 MHz,

CDCl3) δ 252.00, 156.13, 146.23, 145.72, 145.25, 136.23, 129.84, 129.49, 128.61, 125.31, 124.90,

121.40, 117.96, 115.97, 65.39, 52.82, 51.43, 51.24, 48.97, 48.63, 36.88, 35.66, 31.23, 30.97, 30.08,

29.70, 29.48, 29.33, 29.18, 27.89, 27.31, 27.13, 26.11, 24.65, 24.43, 23.19, 23.08, 22.81, 22.73,

22.60, 20.18, 19.72, 2.95, 2.92, 2.89, 2.88, 2.82, 2.81, 2.79, 2.68. Elemental Analysis: Anal. Cacld.

for C39H53CuN2 + 0.75 H2O: C, 74.72%; H, 8.76%; N, 4.47%. Found: C, 74.83%; H, 8.48%; N,

4.18%.

CAACMen-Cu(C6F5) (Cu host). LiC6F5 was prepared by the addition of nBuLi (1.05 mmol,

2.5 M in hexanes) to bromopentafluorobenzene (131 μL, 1.05 mmol) in ether (30 mL) at -78 °C

for 45 minutes (Caution: LiC6F5 is known to explode at temperatures above -40 °C). To the crude

solution of LiC6F5, an ether solution of (MenthylCAAC)CuCl (500 mg, 1.04 mmol, 0.017 M) was

slowly added at -78 °C over 30 minutes. The reaction mixture was then stirred for one hour and

slowly warmed to room temperature for another 12 hours. Subsequently, the mixture was filtered

through celite, and the volatiles were removed under vacuum to afford a pale yellow solid.

Afterwards, the solid was washed with pentane (3x2 mL) to obtain a white powder (497 mg, 78%

yield). Crystals suitable for an X-ray diffraction study were grown from a saturated solution of

benzene layered with pentane. 1H NMR (C6D6, 500 MHz): δ = 7.18 (t, J = 7.80 Hz, 1H), 7.06 (d,

J = 7.80 Hz, 1H), 7.04 (d, J = 7.80 Hz, 1H), 3.01-2.93 (m, 2H), 2.83 (sept, J = 6.10 Hz, 2H), 2.18

(br d, J = 12.42 Hz, 1H), 1.92 (d, J = 12.42 Hz), 1.84-1.76 (m, 3H), 1.38 (d, J = 6.59 Hz, 3H), 1.29

9

(d, 13.16 Hz, 1H), 1.20 (d, J = 12.42 Hz, 1H), 1.14-1.08 (m, 7H), 1.05-0.99 (m, 1H), 0.98 (d, J =

4.1 Hz, 6H), 0.94 (d, J = 6.23 Hz, 3H) 0.90 (d, J = 6.43 Hz, 3H) ppm; 13C NMR (C6D6, 125 MHz):

254.6, 150.2 (d, JF = 222.5 Hz), 150.0 (d, JF = 222.5 Hz), 145.8, 145.3, 139.1 (d, JF = 243.3 Hz),

136.6 (d, JF = 252.3 Hz), 135.8, 130.0, 125.8 (t, 2JF = 74.2 Hz), 125.2, 125.0, 77.7, 65.9, 53.1,

51.6, 48.0, 36.1, 31.4, 29.6, 29.5, 29.2, 29.0, 28.0, 27.5, 26.6, 25.2, 24.2, 23.1, 22.8, 22.6, 20.0

ppm; 19F NMR (C6D6, 282 MHz): δ = -111.9 – -112.2 (m), -160.4 (t, J = 19.8 Hz), -162.9 – -163.2

(m) ppm. Elemental Analysis: Anal. Cacld. for C33H43CuF5N: C, 64.74%; H, 7.08%; N, 2.29%.

Found: C, 64.31%; H, 7.12%; N, 1.90%.

Crystallographic data 

Figure S 1. Oak Ridge thermal ellipsoid plot (ORTEP) representation of 1a. Thermal ellipsoids

shown at 50% probability. Hydrogens and isopropyl (iPr) groups on the 2,6-diisopropylphenyl

(Dipp) moiety removed for clarity.

10

Table S 1. Select bond lengths and angles in complex 1a.

Complex 1a N2-C13-N1-C12 -1.3° (2) C16-C13-N2 108.5° (3)

Σ = 359.8° C16-C13-Cu1 128.4° (3) N2-C13-Cu1 122.9° (2) C13-Cu1-N1 173.51° (9) C1-N1-C12 105.7° (2)

Σ = 358.6° Cu1-N1-C1 130.5° (2) Cu1-N1-C12 122.4° (1) C13-Cu1 1.881 Å (2) Cu1-N1 1.859° Å (2) C13-N1 3.735 Å (3) Space group P21/c 1 molecule in unit cell

Figure S 2. ORTEP representation of 1c. Thermal ellipsoids shown at 50% probability. Hydrogens

and iPr groups on the Dipp moiety removed for clarity.

11

Table S 2. Select bond lengths and angles in complex 1c.

Complex 1c N2-C13-N1-C12 -17.8° (2) C14-C13-Cu1 128.0° (1)

Σ = 359.9° C14-C13-N2 108.9° (2) N2-C13-Cu1 123.0° (1) C13-Cu1-N1 174.40° (8) C1-N1-C12 105.9° (2)

Σ = 359.7° Cu1-N1-C1 125.3° (1) Cu1-N1-C12 128.5° (1)

C13-Cu1 1.867 Å (2) Cu1-N1 1.853 Å (2) C13-N1 3.716 Å (3) Space group P21/c 1 molecule in unit cell

Figure S 3. ORTEP representation of 1d. Thermal ellipsoids shown at 50% probability. Hydrogens

and iPr groups on the Dipp moiety removed for clarity.

12

Table S 3. Select bond lengths and angles in complex 1d. Complex 1d N2-C13-N1-C12 -16.6(1)° C14-C13_N2 108.86° (9)

Σ = 359.94° C14-C13-Cu1 124.92° (8) N2-C13-Cu1 126.16° (8) C13-Cu1-N1 174.58° (5)° C1-N1-Cu1 125.31° (8)

Σ = 359.97° Cu-N1-C12 129.04° (8) C1-N1-C12 105.62° (9) C13-Cu1 1.879 Å (1) Cu1-N1 1.864 Å (1) C13-N1 3.739 Å (1) Space group P21/c 2 molecules in unit cell

Figure S 4. ORTEP representation of 1b adapted from ref x. Thermal ellipsoids shown at 50%

probability. Hydrogens and iPr groups on the Dipp moiety removed for clarity.

Table S 4. Select bond lengths and angles in complex 1b adapted from ref x.

Complex 1b adapted from refx for comparison purposes

N1-C1-N2-C28 -7.8° (2) C2-C1-Cu1 130.7° (1)

Σ = 360.0° C2-C1-N1 108.6° (1) N1-C1-Cu1 120.7° (1) C1-Cu1-N2 174.34° (7) C39-N2-Cu 130.5° (1)

Σ = 359.5° C39-N2-C28 105.5° (1)

13

Cu1-N2-C28 123.5° (1) C1-Cu 1.885 Å (1) Cu1-N2 1.862 Å (1) C1-N2 3.743 Å (2) Space group P21/n 1 molecule in unit cell (+ 1 CH2Cl2)

Figure S 5. ORTEP representation of 2b. Thermal ellipsoids shown at 50% probability. Hydrogens

and iPr groups on the Dipp moiety removed for clarity.

Table S 5. Select bond lengths and angles in complex 2b.

Complex 2b

N1-C2AA-N2-C31 -83.2° (2)

C1AA-C1AA-Cu1 128.1° (1) Σ = 359.3° C1AA-C2AA-N1 107.6° (1)

N1-C2AA-Cu 123.6° (1)

C2AA-Cu1-N2 170.68° (6)

C1-N2-Cu1 128.0° (1) Σ = 359.8° C1-N2-C31 105.2° (1)

Cu1-N2-C31 126.6° (1)

C2AA-Cu1 1.907 Å (1)

N2-Cu1 1.897 Å (1)

C2AA-N2 3.792 Å (2)

Space group P21/c

14

1 molecule in unit cell

Figure S 6. ORTEP representation of 3. Thermal ellipsoids shown at 50% probability. Hydrogens

and iPr groups on the Dipp moiety removed for clarity.

Table S 6. Select bond lengths and angles in complex 3.

Complex 3 N4-C15-N1-C1 -2.0° (2) C16-C15-Cu1 129.3° (1)

Σ = 360.0° C16-C15-N4 108.8° (2) N4-C15-Cu1 121.9° (1) C15-Cu1-N1 177.03° (8) C12-N1-Cu1 128.5° (1)

Σ = 360.0° C12-N1-C1 105.6° (2) Cu1-N1-C1 125.9° (1) C15-Cu1 1.895 Å (2) Cu1-N1 1.875 Å (2) C15-N1 3.769 Å (3) Space group P212121 2 molecules (+ 2 toluene molecules in unit cell)

15

Figure S 7. ORTEP representation of 4. Thermal ellipsoids shown at 50% probability. Hydrogens

and iPr groups on the Dipp moiety removed for clarity.

Table S 7. Select bond lengths and angles in complex 4.

Complex 4

N2-C15-N1-C1 -6.2° (2)

C16-C15-Cu1 129.1° (1) Σ = 359.7° C16-C15-N2 108.2° (2)

N2-C15-Cu1 122.4° (1)

C15-Cu1-N1 174.88° (8)

Cu1-N1-C12 132.5° (1) Σ = 359.9° C12-N1-C1 104.9° (1)

Cu1-N1-C1 122.5° (1)

C15-Cu1 1.882 Å (2)

Cu1-N1 1.856 Å (2)

C15-N1 3.734 Å (3)

Space group P65

1 molecule in unit cell

16

Figure S 8. ORTEP representation of 5. Thermal ellipsoids shown at 50% probability. Hydrogens

and iPr groups on the Dipp moiety removed for clarity.

Table S 8. Select bond lengths and angles in complex 5.

Complex 5

N4-C52-N3-C40 8.7° (5)

C53-C52-N4 109.5° (4) Σ = 359.8C53-C52-Cu2 129.1° (4)

N4-C52-Cu2 121.2° (4)

C52-Cu2-N3 179.0° (2)

Cu2-N3-C46 112.4° (4) Σ = 359.3Cu2-N3-C40 124.6° (3)

C46-N3-C40 122.9° (5)

C52-Cu2 1.882 Å (5)

Cu2-N3 1.854 Å (4)

C52-N3 3.736 Å (7)

Space group P212121

2 molecules in unit cell

17

Figure S 9. ORTEP representation of Cu host. Thermal ellipsoids shown at 50% probability.

Hydrogens and iPr groups on the Dipp moiety removed for clarity.

Table S 9. Select bond lengths and angles in complex Cu host.

Cu host C2-C1-C28-C33 -21.6° (5) C2-C1-Cu1 128.7° (3)

Σ = 360.0 C2-C1-N1 108.4° (3) N1-C1-Cu1 122.9° (3) C1-Cu1-C28 178.5° (2) C33-C28-Cu1 124.5° (3)

Σ = 360.0 C33-C28-C29 113.2° (3) Cu1-C28-C29 122.3° (3) C1-Cu1 1.896 Å (4) Cu1-C28 1.917 Å (4) C1-C28 3.813 Å (5) Space group P21 1 molecule in unit cell

18

N

N

NCu

iPriPr

O

O

O

NCu

iPriPr

H

H

Figure S 10. Crystal structure of the decomposition product of complex 2b in ambient air, showing

a bridging 𝐶𝑂32 moiety and two 1,8-dimethyl-9-H-carbazole moieties within hydrogen-bonding

distances from two of the carboxylate O-.

The crystals with the structures depicted above were grown from slow evaporation of a

toluene solution in ambient air overnight. The yellow crystals were found to contain two CAACAd-

Cu moieties, bridged by a 𝐶𝑂32 , which is hydrogen-bonded to two the NH groups on both

carbazole units. This surprising result signifies the potential for application of our CAAC-Cu-

amide complexes in small molecule activation, namely CO2 and H2O. The applicability of this

chemistry under ambient conditions, as opposed to 1 atm of CO2, is especially interesting. Viewed

in this light, and with the MO picture in bond, one can consider these donor-Cu-acceptor molecules

as a special class of frustrated Lewis pairs, π-type FLP’s with: the filled N orbital comprising the

Lewis Base, the empty π-orbital on the CAAC comprising the Lewis acid, and the Lewis pair

overall frustrated by the metal (at 3.7 Å separation). The orthogonal ligand conformation, which

weakens the π-FLP interaction, appears to further activate these complexes for small molecule

activation.

19

Table S 10. Space filling crystal structures of complexes 1a and 1b, showing the extra

encumbrance imposed by the menthyl group in 1a.

1a 1b

20

Electrochemical characterization 

-3 -2 -1 0 1-150

-125

-100

-75

-50

-25

0

25

50

75

I (A

)

Potential (V)

CAACMen-CuCz (ox, DMF) CAACMen-CuCz (red, DMF) CAACMen-CuCl (DMF) Cz(AcN) KCz (DMF)

(a)

-3 -2 -1 0 1

-100

-50

0

50

I (

Potential (V)

CAACMen-Cu(CN2Cz) (AcN)

CAACMen-Cu(CN2Cz)

CAACMen-CuCl (DMF) CN

2Cz (AcN)

(b)

-3 -2 -1 0

-150

-100

-50

0

50

100

I (

Potential (V)

CAACMen-Cu(OMe2Cz) (DMF)

CAACMen-Cu(OMe2Cz)

CAACMen-CuCl OMe

2Cz

(c)

-3 -2 -1 0 1

-100

-50

0

50

100

I (

Potential (V)

CAACMen-CuNPh2 (DMF)

CAACMen-CuNPh2

CAACMen-CuCl HNPh

2

(d)

-3 -2 -1 0 1-100

-50

0

50 CAACMen-CuC

6F

5, Cu host

CAACMen-CuCl

I (

Potential (V)

(e)

Figure S 11. Differential pulse voltammetry traces for complexes 1a (a), 3 (b), 4 (c), 5 (d) and Cu host as well as their parent ligands.

21

Table S 11. Redox potentials of complexes 1a, 3 - 5 as well as KCz, the parent amines,

CAACMen-CuCl precursor, and Cu host.

Eox (V) Ered (V) ΔEredox (V) 1a 0.24 (ir) -2.84 (q) 3.08 3a 0.69 (ir) -2.79 (q) 3.48 4 -0.20 (ir) -2.85 (q) 2.65 5 -0.29 (ir) -2.89 (q) 2.60 KCz -0.49 (ir) --- --- Cza 0.84 (ir) --- --- 4,4’-CN2Cza 1.38 --- --- 4,4’-OMe2Cz 0.44 --- --- HNPh2 0.45 --- --- Cu host 0.90 -2.7 3.6 CAACMen-

CuCl > 1.5b -2.85 ---

Potentials versus ferrocenium/ferrocene obtained in DMF with 0.1 M TBAPF6. aPotentials obtained in acetonitrile. bOxidation not observed in the DMF solvent window. ir = irreversibie, q = quasi-reversible.

22

Density Functional Theory Calculations 

Common hybrid functionals, such as B3LYP and PBE0, have been reported to severely

underestimate the energies of charge transfer states,(62-64) whereas long-range corrected

functionals, such as CAM-B3LYP, PBE and B97xD, better match the observed energies.(65-

68) In this work, TDDFT calculations performed using the CAM-B3LYP functional were found

to offer good agreement with experimental values. For all CAAC-Cu-amide complexes, the first

two singlet excited states can be characterized as interligand charge-transfer, from the amide to the

carbene ligand, i.e. 1ICT from the amide to the carbene ligand. These states are characterized by

high oscillator strengths (f > 0.1).

Table S 12. Frontier MO surfaces of the complexes computed at the B3LYP/LACVP** level.

HOMO (eV) LUMO (eV)

1a

-4.16 -1.50

1b

-4.13 -1.52

1c

-4.16 -1.58

1d

23

-4.13 -1.52

2a

-4.13 -1.50

2b

-4.05 -1.60

3

-5.14 -1.96

4

-3.75 -1.50

5

-3.84 -1.36

Cu host

-6.01 -1.55

24

Photophysical characterization  

250 300 350 400 450 5000.0

0.5

1.0

Ab

sorb

ance

(a.

u.)

Wavelength (nm)

CAACMen-CuCz (1a) Cz CAACMen-CuCl

Figure S 12. Absorption spectrum of complex 1a and its parent ligands CAACMen-CuCl and

9-H-carbazole in THF.

250 300 350 400 4500.0

0.5

1.0

Ab

sorb

ance

(a.

u.)

Wavelength (nm)

CAACMen-Cu(CN2Cz) (3)

CN2Cz

Figure S 13. Absorption spectrum of complex 3 and parent 3,5-dicyano-9-H-carbazole in THF.

25

250 300 350 400 450 500 5500.0

0.5

1.0

1.5

Ab

sorb

ance

(a.

u.)

Wavelength (nm)

CAACMen-Cu(OMe2Cz) (4)

OMe2Cz

Figure S 14. Absorption spectrum of complex 4 and parent 3,5-dimethoxy-9-H-carbazole in THF.

300 350 400 450 500 550 6000.0

0.5

1.0

Ab

sorb

ance

(a.

u.)

Wavelength (nm)

CAACMen-CuNPh2 (5)

HNPh2

Figure S 15. Absorption spectrum of complex 5 and parent diphenylamine (in THF).

26

250 300 350 400 450 5000

1

2

(x104 M

-1.c

m-1)

Wavelength (nm)

1a 1b 1c 1d

Figure S 16. Extinction coefficients of complexes 1a - 1d in THF.

250 300 350 4000.0

2.5

5.0

7.5

10.0

(x

104

M-1.c

m-1)

Wavelength (nm)

Cu host, THF

Figure S 17. Extinction coefficient of complex Cu host in THF.

27

250 300 350 400 450 500 550 6000

1

2

3

Ab

so

rba

nc

e (

a. u

.)

Wavelength (nm)

1a 3 4 5

Figure S 18. Absorption spectra of complexes 1a, 3, 4, 5 in methylcyclohexane (MeCy).

350 400 4500

1

2-MeTHF

No

rmal

ized

Inte

nsi

ty (

a. u

.)

Wavelength (nm)

298 K, C1 298 K, C2 298 K, C3 195 K, C1 195 K, C2 125 K, C3 77 K, C1 77 K, C2 77K, C3

*

Figure S 19. Absorption spectra of solutions of 1a in 2-MeTHF at three concentrations, collected

at 298 K, 195 K, and 77K 195K was attained in a medium of dry-ice/acetone. Hence, the spectra

are normalized to the peak at 370 nm (marked with an asterisk), beyond the absorption cut-off of

acetone. C1 = 2.2 x 10-4 M, C2 = 4.2 x 10-5 M, C3 = 2.2 x 10-5 M. The trends in hypsochromic shifts

with decreasing temperatures are concentration-independent. Unfortunately, solubility limitations

of the complex in MeCy thwarted similar studies over meaningful concentration ranges.

28

0.0

0.5

1.0

400 500 600 700

400 500 600 7000.0

0.5

1.0

RT

1a 1b 1c 1d

77K

No

rmal

ized

In

ten

sity

(a.

u.)

Wavelength (nm)

1a 1b 1c 1d

Figure S 20. Emission spectra of complexes 1a - 1d in 2-MeTHF at room temperature (RT, top)

and 77K (bottom).

Table S 13. Photophysical properties of complexes 1a - d in 2-MeTHF at RT and 77K.

Emission at room temperature Emission at 77K λmax

(nm) τ (μs) ΦPL kr (s-1) knr (s-1)

λmax (nm)

τ (μs)

1a 492 2.5 1.0 3.9 x 105 < 8.0 x

103 430 7300

1b 510 2.3 0.68 3.0 x 105 1.7 x 105 430 3000 (430 nm);

48 (550 nm) 1c 500 1.8 0.56 3.1 x 105 2.4 x 105 430 7000 1d 510 0.54 0.11 2.0 x 105 1.6 x 106 430 5000

29

300 400 500 600 7000.0

0.5

1.0

No

rmal

ized

Inte

nsi

ty (

a. u

.)

Wavelength (nm)

Em, MeCy Ex, MeCy Em, toluene Ex, toluene Em, 2-MeTHF Ex, 2-MeTHF Em, CH

2Cl

2

Ex, CH2Cl

2

Figure S 21. Excitation (dashed lines) and emission (solid lines) spectra of complex 1a in solvents

of increasing polarity. The excitation spectra show unambiguously that emission in 2-MeTHF,

MeCy, and toluene stems from the lowest-lying CT state, which is stabilized in these solvents (in

agreement with the absorption spectra in Figure 1A). In CH2Cl2, the strong solvent polarity

destabilizes the CT state to higher energies than 3Cz, as seen in the excitation and absorption

spectra. Emission in CH2Cl2 is still broad and featureless, with kr > 105 s-1. Hence, emission in

CH2Cl2 results from thermal population of the higher-lying CT state from the lower-lying 3Cz,

which may explain the reduced ΦPL in this solvent.

Table S 14. Photophysical properties of complex 1a in solvents of increasing polarity as well as in

neat thin film form. aNon-Gaussian emission.

Emission at room temperature Emission at 77K

λmax (nm) τ (μs) ΦPL kr (s-1) knr (s-1) λmax (nm)

τ (μs)

MeCy 486; 468a 2.3 0.92 4.0 x 105 3.5 x 104 430 6700

Toluene 488 2.5 1.0 4.0 x 105 < 4.0 x

103 --- ---

2-MeTHF 492 2.5 1.0 3.9 x 105 < 8.0 x

103 430 7300

CH2Cl2 482 1.6 0.4 2.5 x 105 3.8 x 105 --- --- Neat thin

film 474 1.3 0.65 4.9 x 105 2.6 x 105 482 70.4

30

400 450 500 550 600 650 7000.0

0.5

1.0

No

rmaliz

ed In

ten

sity

(a.

u.)

Wavelength (nm)

SS, RT SS, 77K neat film, RT neat film, 77K

Figure S 22. Emission spectra of complex 1a in its microcrystalline powder form and as neat thin

films at RT (solid lines) and 77K (dashed lines). The narrow, structured emission of the

microcrystalline powder appears to be 3Cz in origin (at 430 nm) as well as aggregate induced (at

580 nm). Processing the powders into thin films breaks up the aggregates and results in broad,

featureless ICT emission.

400 500 600 7000.0

0.5

1.0

No

rma

lize

d In

ten

sit

y (

a. u

.)

Wavelength (nm)

(1a), RT (1a), 77K (2b), RT (2b), 77K

microcrystalline powders

31

Figure S 23. Emission spectra of microcrystalline powders of complexes 1a and 2b at RT (slid

lines) and 77K (dashed lines). The orthogonal ligand conformation in 2b breaks up aggregation

seen in 1a, ultimately resulting in ICT emission in the microcrystalline powder form.

Table S 15. Photophysical properties of microcrystalline powders (or solid state, SS) of complex

2b at RT and 77K. acalculated from weighted average.

Emission at room temperature Emission at 77K λmax (nm)

τ (μs) ΦPL kr (s-1)a knr (s-1)a λmax (nm)

τ (μs)

SS 492 2 (30%);

11.2 (70%)

0.61 7.2 x 104 4.6 x 104 508 34 (at 550

nm)

400 500 600 700 8000.0

0.5

1.0

No

rmal

ized

Inte

nsi

ty (

a. u

.)

Wavelength (nm)

(1b), RT (1b), 77K (2b), RT (2b), 77K

Figure S 24. Emission spectra of complexes 1b and 2b in 2-MeTHF at RT (solid lines) and 77K

(dashed lines). In both temperatures, RT emission is broad, featureless with kr on the order of 105

s-1: ICT in nature. 2b is slightly red-shifted relative to 1b likely due to its more electron-rich

32

1,8-dimethyl-9-H-carbazole. At 77K, both complexes show emission that is mostly narrow and

sharp, exhibiting a bi-exponential PL decay. At ~ 430 nm, emission in both complexes has τ ~ ms,

indicating the 3Cz nature of the emissive state. At ~ 550 nm (77K) in both complexes, τ ~ 10’s of

μs, likely stemming from 3ICT, reflecting the TADF operant within the ICT manifold. Emission

out of 3Cz and 3ICT channels at 77K can be attributed to different conformers that can no longer

equilibrate upon freezing.

300 400 500 600 700 8000.0

0.5

1.0

No

rmal

ized

Inte

nsi

ty (

a. u

.)

Wavelength (nm)

Em, MeCy Ex, MeCy Em, toluene Ex, toluene Em, 2-MeTHF Ex, 2-MeTHF Em, CH

2Cl

2

Ex, CH2Cl

2

Em, AcN Ex, AcN

Figure S 25. Excitation (dashed lines) and emission (solid lines) spectra of complex 5 in solvents

of increasing polarity. While strong negative-solvatochromism is apparent in the excitation spectra

(in agreement with absorption spectra), emission appears to be weakly-dependent on solvent

polarity.

33

300 400 500 600 7000.0

0.5

1.0

No

rmal

ized

Inte

nsi

ty (

a. u

.)

Wavelength (nm)

Em, RT Em, 77K Ex, RT Ex, 77K

* 2nd harmonic

Figure S 26. Excitation (dashed lines) and emission (solid lines) spectra of microcrystalline

powders of complex 5 at RT and 77K. Excitation is recorded at 550 nm emission. The red-shift in

emission recorded upon cooling is one of the two hallmarks of thermally-activated delayed

fluorescence, TADF. The other is the increase in the radiative lifeitme reported in Table S14.

Table S 16. Photophysical properties of complex 5 in solvents of increasing polarity as well as in

the microcrystalline solid form (SS) at RT and 77K.

Emission at room temperature Emission at 77K λmax

(nm) τ (μs) ΦPL kr (s-1) knr (s-1)

λmax (nm)

τ (μs)

MeCy 556 2.38 0.55 2.3 x 105 1.9 x 105 556 193 Toluene 468 1.43 0.41 2.9 x 105 4.1 x 105 --- ---

2-MeTHF

580 0.87 0.16 1.8 x 105 9.7 x 105 498 215

CH2Cl2 568 0.88 0.24 2.7 x 105 8.6 x 105 --- --- AcN 584 0.47 0.11 2.3 x 105 1.9 x 106 --- ---

SS 496 4.1 1.0 2.4 x 105 < 2.4 x

103 518 87

34

0.0

0.5

1.0

400 500 600 700

400 500 600 7000.0

0.5

1.0

RTN

orm

aliz

ed In

ten

sity

(a.

u.)

1a 3 4 5

77 K

*

* excimer

Wavelength (nm)

1a 3 4 5

Figure S 27. Emission spectra of complexes 1a, 3, 4, and 5 in 2-MeTHF at room temperature (RT,

top) and 77K (bottom).

35

0.0

0.5

1.0

400 500 600 700

400 500 600 7000.0

0.5

1.0

No

rmal

ized

Inte

nsi

ty (

a. u

.) 1a 3 4 5

*

*excimer

Wavelength (nm)

1a 3 4 5

RT

77 K

Figure S 28. Emission spectra of complexes 1a, 3, 4, and 5 in MeCy at room temperature (RT, top)

and 77K (bottom).

Table S 17. Photophysical properties of complexes 1a, 3 - 5 in MeCy at RT and 77K. aexcimer

emisssion.

Emission at room temperature Emission at 77K λmax (nm)

τ (μs) ΦPL kr (s-1) knr (s-1) λmax (nm)

τ (μs)

1a 486 2.3 0.92 4.0 x 105 3.5 x 104 430 6700

3 428; 586a

450 nm: 5.9 600 nma:

2.3 (-7%); 20.5 (107%)

0.19 --- --- 422 5300

4 542 1.12 0.62 5.5 x 105 3.4 x 105 472 Seconds 5 556 2.38 0.55 2.3 x 105 1.9 x 105 530 193

36

0.0

0.5

1.0

400 500 600 700

400 500 600 7000.0

0.5

1.0 77K

No

rmal

ized

Inte

nsi

ty (

a. u

.) 1a 3 4 5

RT

Wavelength (nm)

1a 3 4 5

Figure S 29. Emission spectra of thin PS films (1 wt%) of complexes 1a, 3, 4, and 5 at room

temperature (RT, top) and 77K (bottom).

37

450 500 550 600 6500.0

0.5

1.0

No

rma

lize

d I

nte

ns

ity

(a. u

.)

Wavelength (nm)

9.6 K 60 K 100 K 140 K 180 K 220 K 260 K 198 K

exc @ 400 nm

Figure S 30. Temperature-dependent emission spectra of a thin film of complex 1a (doped into PS

at 1 wt%).

500 600 700 8000.0

0.5

1.0

No

rmal

ized

Inte

ns

ity

(a.

u.)

Wavelength (nm)

10K 50K 90K 130K 170K 210K 250K 298K 310K

Figure S 31. Temperature-dependent emission spectra of a thin film of complex 5 (doped into PS

at 1 wt%).

38

300 350 4000

1

2

3S

cal

ed

ab

so

rban

ce (

a. u

.)

Wavelength (nm)

MeCy Toluene 1% PS film THF CH

2Cl

2

AcN

Figure S 32. Absorption spectra of complex 3 in various matrices, showing limited negative

solvatochromism (compared to that observed in 1a and 5), consistent with the strongly destabilized

ICT state. In non-polar solvents where the ICT band exhibits a red-shift to lower wavelengths, it’s

still higher in energy than 3Cz.

39

0.0

0.5

1.0

400 500 600 700

400 500 600 7000.0

0.5

1.0

No

rmal

ized

Inte

nsi

ty (

a. u

.)RT

MeCy toluene 2-MeTHF 1% PS

Wavelength (nm)

77K MeCy 2-MeTHF 1% PS

Figure S 33. Emission spectra of complex 3 in various matrices at RT (top) and 77K (bottom).

40

0.0

0.5

1.0

400 500 600 700 800

400 500 600 700 8000.0

0.5

1.0

No

rmal

ized

Inte

nsi

ty (

a. u

.)MeCy

conc 5x dilute

0 40 800

1 440 nm 600 nm

No

rmal

ized

co

un

ts (

a. u

.)

time (s)

Wavelength (nm)

Toluene conc 2x dilute

Figure S 34. Emission spectra of complex 3 in MeCy (top) and toluene (bottom) at two different

concentrations. The inset (top, right corner) shows the PL decay traces recorded at 440 nm and

600 nm in MeCy. While the decay at 440 nm is monoexponential, at 600 nm it is biexponential

and shows a rise time, consistent with excimer formation and emission.

Table S 18. Photophysical properties of complex 3 in MeCy and 2-MeTHF.

Emission at room temperature Emission at 77K λmax (nm)

τ (μs) ΦPL kr (s-1) knr (s-1) λmax (nm)

τ (μs)

MeCy 428; 590

450 nm: 5.9 600 nm: 2.3 (-7%); 20.5

(107%)

0.19 --- --- 422 5300

2-MeTHF 428; 590

450 nm: 8.3 600 nm: 0.3 (-2%); 8.0

(102%)

0.11 --- --- 422 12000

41

OLED fabrication and characterization

OLED devices were fabricated on pre-patterned ITO-coated glass substrates (20 ± 5 Ω cm-2,

Thin Film Devices, Inc.). Prior to deposition, the substrates were cleaned with soap, rinsed with

deionized water and sonicated for 15 minutes. Afterwards, two subsequent rinses and 12-minute

sonication baths were performed in acetone and isopropyl alcohol sequentially. All organic layers

as well as the Al cathode were deposited in a vacuum thermal evaporator, EVO Vac 800 deposition

system from Angstrom Engineering, at 6 x 10-7 Torr.

Current-voltage-luminescence (J-V-L) curves were using a Keithley power source meter

model 2400 and a Newport multifunction optical model 1835-C, PIN-220DP/SB blue-enhanced

silicon photodiodes (OSI optoelectronics Ltd.). The sensor was set to measure power at an energy

of 520 nm, followed by correcting to the average electroluminescence wavelength for each

individual device during data process. Electroluminescence (EL) spectra of OLEDs were measured

using the fluorimeter (model C-60 Photon Technology International QuantaMaster) at several

voltages.

Figure S 355. Device architecture used in our work on device optimization summarized in Table

S17. The dopant in the EML of all devices is 1a. The structures of 2,2',2"-(1,3,5-Benzinetriyl)-

tris(1-phenyl-1-H-benzimidazole) (TPBi) and 4,4'-Cyclohexylidenebis[N,N-bis(4-

methylphenyl)benzenamine] (TAPC), used in the ETL and HTL respectively, are shown on the

right.

42

Table S 19. Frontier orbital and T1 energies of the different materials employed in the EML of our

OLEDs.

HOMO (eV) LUMO

(eV) 𝑬𝑻𝟏 (eV)

1a -5.1 -1.5 2.88 Cu host -5.8 1.6 3.1 mCBP -6.0 -1.5 2.9 mCP -6.1 -1.5 2.91

UGH3 -7.1 -1.0 3.5

Figure S 36. (A) Device architectures fabricated to figure out whether mCP can function as a

blocker (B) EQE plot (C) J-V-L curve (D)-(F) Electroluminescence spectrum of devices.

Maximum EQEs are 1.5% at 0.15mA/cm2 and 1.3% at 0.2mA/cm2 for D1 and D2 respectively.

Turn on voltages for D1 and D2 are 4.6V, 4.3V respectively. Maximum luminance for D1 and D2

is 4404 cd/m2 and 3039 cd/m2 respectively. Maximum luminance efficiency for D1 and D2 is

2.9cd/A and 2.7cd/A respectively.

43

Firstly, as shown in figure S 36, D1 and D2 devices were fabricated to investigate the

functionality of mCP as an exciton blocker. 10nm of mCP next to NPD was introduced to prevent

direct exciton leakage from EML to NPD. Overall, device with mCP blocker (D1) is less

conductive than D2 (Figure S 36 C) due to deeper HOMO of mCP that that of Cu emitter. However,

maximum EQEs of both D1 and D2 are the almost the same (Figure S 36 B), indicating that

employing mCP layer between EML and ETL interface does not change the efficiency of device.

As a next step, devices with two doping concentrations (5, 10 vol%) in three different hosts

(mCBP, mCP, Cu host) were fabricated to find a suitable host (Figure S 37). As indicated in figure

S 37 (B), highest EQE (4.0%) was achieved with Cu host-based device, implying Cu host is a

promising candidate for host material. However, once Cu host was introduced, devices showed

degradation upon operation, corresponding to the growth of unexpected emission near 550nm

(figure S 37 F and I). Emitter 1a was more highly doped into Cu host to check stability of the

device (Figure S 38). Variation of EL profile over voltages became less severe (Figure S 38 D) but

device efficiency also dropped (Figure S 38 B). This result implies that charge balance, quantum

yield of emissive layer and device stability are all correlated. In order to fabricate stable and

efficient Cu host-device, thicker EMLs (40nm) with various doping conditions (5, 10, 20, 30 vol%)

were employed (Figure S 39). The rationale of thickening EML is to spread out triplet densities in

the emissive layer, contributing to mitigation of TTA and TPA. As shown in figure S 39 D, EL

spectrum of device is stable during operation. The device yields 9.2% of maximum EQE at

0.3mA/cm2. These results prove that extended emissive layer contributes to not only stability but

also efficiency of the device. To further increase EQE, thickness of ETL was varied (D1 and D2),

expecting to improve outcoupling efficiency (Figure S 40). D2 device showed slightly enhanced

EQE (9.5%) than that of D1 (9.2%).

44

Figure S 37. (A) Device architectures with different hosts and doping concentrations. Thickness

of EML is 20nm. (B) EQE plot (C) J-V-L curve (D)-(F) Electroluminescence spectra collected

from devices with 10 vol% doping concentration of 1a as an emitter in mCBP, mCP, Cu host

respectively. (G)-(I) Electroluminescence spectra collected from devices with 5 vol% doping

concentration of 1a as an emitter in mCBP, mCP, Cu host respectively.

45

Figure S 38. (A) Device architecture. Thickness of EML is 20nm. (B) EQE plot (C) J-V-L curve

(D)-(F) Electroluminescence spectrum of the device at different voltages

46

Figure S 39. Performances of devices employing 1(a) as an emitter in a Cu host with different

doping concentration (5, 10, 20 and 30 vol%). The architecture of device is

TAPC(40nm)/EML(40nm)/TPBI(40nm)/LiF(1nm)/Al(100nm).

47

Figure S 40. Performances of devices employing 1(a) as an emitter in a Cu host with 20 vol%

doping concentration. (A) Device structure (B) EQE plot (C) J-V-L curve (D) EL spectrum

Even though the TAPC(40nm)/Cu host:1(a)(40nm)/TPBI(40nm)/LiF(1nm)/Al(100nm)

device generates reasonable EQE (9.2%), efficiency roll-off at high current density is still steep

(Figure S 39 A). Therefore, an ultra-band gap material, UGH3 (ET=3.5eV) was used in place of

the Cu host in the same device structure that was optimized for Cu host-device, expecting to

provide less efficiency roll-off (Figure S 41). Figure S 41 B indicates that device becomes more

conductive as doping concentration increases. This is because HOMO/LUMOs are entirely nested

in UGH3 host. Additionally, unlike Cu host-based devices, EL spectrum proves that the light is

exclusively emitted from 1a and do not change significantly at high voltages, indicating device is

stable. Optimized condition is 20% doping with 50nm of ETL which shows 8.4% of maximum

EQE (Figure S 41 A). Overall performance of devices with the same conditions (20 vol%) but

different four hosts (UGH3, mCBP, mCP, Cu host) are summarized in figure S 42. Efficiency roll-

off at high current density is less steep in the case of UGH3 host-based device compare to Cu host-

48

based device (Figure S 42 B). Parameters and measurements of all devices are summarized in

Table S20.

Figure S41. Performances of devices employing 1(a) as an emitter in a UGH3 host with various

doping concentration (5, 10, 20, 25 vol%). The structure of devices are: TAPC(40nm)/UGH3:1(a)

x vol%(40nm)/TPBI(40nm)/LiF(1nm)/Al(100nm), x=5, 10, 20, 25. Note that thickness of TPBI is

49

50nm for 20 vol% doping concentration. (A) EQE curve with various doping concentrations, (B)

J-V-L curve (C), (D), (E) and (F) EL spectrum with various doping conditions at different voltages

Figure S42. Performances of devices employing 1(a) as an emitter in four different hosts with 20

vol% doping concentration. (A) The device structure (B) EQE traces of devices employing 1a in

all four hosts. (C) J-V-L characteristics of devices employing 1a doped into mCBP (black,

squares), mCP (red, circles), Cu host (blue triangles), and UGH3 (green diamonds) in the EML.

(D) EL spectrum in four different hosts.

50

Table S 20. Summary of device optimization where the following parameters in the EML were

varied: the host (UGH3, mCBP, mCP, and Cu host), EML thickness (40 nm), and doping

concentration (5%, 10%, 20% and 25%). The device architectures are: TAPC(40)nm/EML(20,

40nm)/TPBI(40nm, 50nm)/LiF(1nm)/Al(100nm). a) Turn on voltage was determined as the voltage

at 1cd/m2.

Host EML

thickness (nm)

Doping concentration

(vol %)

EQEmax

(%)

Current density

at EQEmax

(mA/cm2)

a)Vturn on

(V) Max cd/A

Max cd/m2

UGH3

40 5 7.4 0.1 4.2 10.8 976.1

40 10 5.0 2.6 3.6 7.6 2396

40 20

(ETL=50nm) 8.4 1.8 4.0 15.6 3797

40 25 2.6 35.3 3.1 4.3 4517

mCBP

20 5 0.7 11.7 3.1 1.2 845.7

20 10 0.6 25.9 2.8 1.1 1281

40 20 4.0 10.3 2.8 1.7 2365

mCP

20 5 0.5 11.5 3.5 0.4 418.9

20 10 0.4 17.7 3.4 0.3 286.6

40 20 1.1 69.1 3.3 1.6 1304

Cu host

20 5 4.2 0.008 3.5 3.1 123.2

20 10 3.2 0.1 3.2 3.5 196.5

20 20 2.6 1.9 3.1 3.4 296.9

40 5 0.8 0.009 4.5 0.8 15.4

40 10 1.1 0.02 4.1 1.2 44.7

40 20

9.2 0.3 4.4 10.3 391.7

9.5 (ETL= 50nm)

0.2 4.4 12.5 433.8

40 30 1.2 10.6 3.1 1.8 515.7

51

Time dependent DFT (TDDFT) and Molecular Dynamics 

Table S 21. Calculated singlet and triplet excited state energies for the complexes in this paper

obtained through TDDFT performed at the CAM-B3LYP/LACVP** level. Also reported are

∆𝐸1𝐼𝐶𝑇 3𝐼𝐶𝑇, the energy gap between the closest-lying ligand localized state (3LE) and interligand

charge transfer (3ICT), ∆𝐸3𝐿𝐸 3𝐼𝐶𝑇, the S1 oscillator strength fS1, and the excited state dipole

moment, μES. The character of the states was assigned based on the largest MO contributions

associated with the transition. The 3LE state in complexes 1a – d, 2b, 3, and 4 is carbazolide-

centered (referred to 3Cz in the manuscript) and diphenyl-amide centered in complex 5 (referred

to as 3NPh2 in the manuscript).

E (eV) fS1

T1 T2 T3 S1 S2 S3 ΔE1CT-

3CT

ΔE3LE-

3CT

1a 2.99 (CT)

3.02 (LE)

3.23 (LE)

3.25 (CT)

3.89 (CT)

4.11 (LE)

0.26 0.03 0.123

1b 2.99 (CT)

3.12 (LE)

3.19 (CT)

3.23 (CT)

3.66 (CT)

4.18 (CT)

0.24 0.13 0.112

1c 2.91 (CT)

3.02 (LE)

3.23 (LE)

3.17 (CT)

3.87 (CT)

4.04 (CT)

0.26 0.11 0.128

1d 2.97 (CT)

3.02 (LE)

3.22 (LE)

3.23 (CT)

3.90 (CT)

4.20 (CT)

0.26 0.05 0.125

2b 2.98 (CT)

3.04 (LE)

3.09 (CT)

3.06 (CT)

3.57 (CT)

4.06 (CT)

0.08 0.06 0.005

3 2.91 (LE)

3.14 (LE)

3.38 (LE)

3.79 (CT)

4.06 (CT)

4.11 (LE)

--- < -0.47 0.144

4 2.67 (CT)

2.80 (LE)

2.95 (LE)

2.94 (CT)

3.70 (LE)

4.02 (CT)

0.27 0.13 0.129

52

5 2.68 (CT)

3.04 (LE)

3.33 (CT)

2.96 (CT)

3.75 (CT)

4.09 (CT)

0.28 0.36 0.102

Cu host

3.27 (CT)

3.38 (LE)

3.48 (LE)

3.78 (CT)

4.75 (CT)

4.82 (CT)

0.51 0.11 0.011

A simulation cell was built by populating 128 2-MeTHF solvent molecules around the

complex following which a 200ns NPT MD simulation (P = 1 atm, T = 300 K) was performed

using the OPLS2005 forcefield.(69) The atomic charges of the forcefield for the complex were

replaced by esp-fitted (electrostatic potential) point charges of the 3CT state derived from UDFT

(ωPBEh/6-31G** with =0.263 bohr-1 tuned to satisfy the GDD criterion(60) to get a balanced

description of CT and LE states) while those of the 2-MeTHF molecules were replaced by ground

state esp-fitted point charges calculated at the B3LYP/6-31G** level. This was done to

approximate the response of the solvent molecules to the 3CT excited state at 300 K. 50 snapshots

were extracted from the last 100ns of the MD run, and TDDFT (ωPBEh/6-31G**) calculations

were performed on each snapshot where all the atoms of the 2-MeTHF molecules were replaced

with the corresponding esp-fitted point charges to serve as a polarizing influence on the complex

which was treated at the TDDFT level.

To model the phenomena occurring at 77K, a series of 10 ns NVT runs were performed on

the 300 K equilibrated cell in steps of decreasing temperatures (300-200-100-77 K) followed by a

200 ns NPT simulation (P = 1 atm, T = 77 K). In this case, the atomic charges of the OPLS2005

forcefield were replaced by the ground state esp-fitted charges for both the complex and the solvent

molecules computed at the ωPBEh/6-31G** and B3LYP/6-31G** levels respectively. The

simulation resulted in a frozen rigid equilibrated cell which was used to perform a single point

TDDFT calculation, as done in the previous case. Under these conditions, it was found that the

53

3Cz state becomes the lowest lying triplet (2.90 eV) in accordance with the experimental

observation of 3Cz emission in 2-Me-THF at 77 K.

Table S 22. State dipole moments (μ) computed at the CAM-B3LYP/LACVP** level.

µ (D)

GS 3CT 3LE

1a 11.80 4.25 11.27

1b 11.76 5.47 11.18

1c 12.18 5.11 11.62

1d 12.01 4.50 11.45

2a 11.58 2.46 13.80

3 20.41 15.70 20.37

4 13.25 0.99 12.64

5 10.01 6.66 10.43

Cu host 11.21 6.80 10.29

54

2.5 2.6 2.70

5

10

Cou

nt

T1 (eV)

Figure S 41. Histogram of T1 energies computed for 50 snapshots of the NPT MD run at 300K.

Figure S 42. Solvation effects operating in a polar medium, 2-MeTHF, on the ground and ICT

excited state dipoles (μ-GS and μ-CT respectively) at room temperature (fluid medium) and 77K

(frozen glass).

55

Figure S 43. Solute-solute interactions operating in non-polar fluid and frozen media that can

explain the observed destabilization in of the ICT state at low temperatures.

56

NMR Spectra 

Figure S 44. Variable temperature (VT) 1H NMR spectra of 1a in CDCl3.

57

Figure S 45. 1H NMR spectrum of 1a in CDCl3.

Figure S 46. 13C NMR spectrum of 1a in CDCl3.

58

Figure S 47. 1H NMR spectrum of 1c in CDCl3.

Figure S 48. 13C NMR spectrum of 1c in CDCl3.

59

Figure S 49. 1H NMR spectrum of 1d in CDCl3.

Figure S 50. 13C NMR spectrum of 1d in CDCl3.

60

Figure S 51. 1H NMR spectrum of 2b in CD2Cl2.

Figure S 52. 13C NMR spectrum of 2b in CD2Cl2.

61

We note here that the chemical shift of the Ccarbene is shifted significantly down field (257

ppm) compared to the other carbazolide complexes 252-250 ppm. This signifies that the carbene-

Cu interaction is weakened in for 2b, since Ccarbene is deshielded. The chemical shift of Ccarbene in

the free carbene is at around 315 ppm. Thus, the carbene in 2b can be thought of as being closer

to a free carbene.

Figure S 53. 1H NMR spectrum of 3 in CDCl3.

62

Figure S 54. 13C NMR spectrum of 3 in CDCl3.

Figure S 55. 1H NMR spectrum of 4 in CDCl3.

63

Figure S 56. 13C NMR spectrum of 4 in CDCl3.

64

Figure S 57. 1H NMR spectrum of 5 in CDCl3.

Figure S 58. 13C NMR spectrum of 5 in CDCl3.

65

Figure S 59. 1H NMR spectrum of Cu host in C6D6.

66

Figure S 60. 13C NMR spectrum of Cu host in C6D6.

Figure S 61. 19F NMR spectrum of Cu host in C6D6.

67

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