Supporting information

Substituents Engineered Deep-Red to Near Infrared Phosphorescence from tris-Heteroleptic IridiumIII Complexes for

Solution Processable Red-NIR Organic Light-Emitting Diodes

Hae Un Kim,1‡ Sunyoung Sohn,2‡ Wanuk Choi,3 Minjun Kim,1 Seung Un Ryu,1 Taiho Park,1*

Sungjune Jung,2* K. S. Bejoymohandas1*

1 Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea

2 Department of Creative IT Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea

3 Division of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea

*E-mail: sjjung@posetch.ac.kr; taihopark@postech.ac.kr; bejoymohan@postech.ac.kr

Electronic Supplementary Material (ESI) for Journal of Materials Chemistry C.This journal is © The Royal Society of Chemistry 2018

Contents

Figure S1 1H-NMR spectrum of ethyl 2-chloroquinoline-4-carboxylate (L3a).

Figure S2 13C-NMR spectrum of ethyl 2-chloroquinoline-4-carboxylate (L3a).

Figure S3 1H-NMR spectrum of 2-chloro-4-(trifluoromethyl)quinoline (L4a)

Figure S4 13C-NMR spectrum of 2-chloro-4-(trifluoromethyl)quinoline (L4a)

Figure S5 19F-NMR spectrum of 2-chlro-4-(trifluoromethyl)quinoline (L4a)

Figure S6 1H-NMR spectrum of 2-(benzo[b]thiophen-2-yl)-4-methylquinoline [btmq] (L1).

Figure S7 13C-NMR spectrum of 2-(benzo[b]thiophen-2-yl)-4-methylquinoline [btmq] (L1).

Figure S8 1H-NMR spectrum of 2-(benzo[b]thiophen-2-yl)quinoline [btq] (L2).

Figure S9 13C-NMR spectrum of 2-(benzo[b]thiophen-2-yl)quinoline [btq] (L2).

Figure S10 1H-NMR spectrum of ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate [btecq] (L3).

Figure S11 13C-NMR spectrum of ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate [btecq] (L3).

Figure S12 1H-NMR spectrum of 2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline [bttmq] (L4).

Figure S13 13C-NMR spectrum of 2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline [bttmq] (L4).

Figure S14 19F-NMR spectrum of 2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline [bttmq] (L4).

Figure S15 1H-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-methylquinoline] iridium(III) (thenoyltrifluoroacetonate): (btmq)2Ir(tta) (Ir1).

Figure S16 13C-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-methylquinoline] iridium(III) (thenoyltrifluoroacetonate): (btmq)2Ir(tta) (Ir1).

Figure S17 19F-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-methylquinoline] iridium(III) (thenoyltrifluoroacetonate): (btmq)2Ir(tta) (Ir1).

Figure S18 MALDI TOF MASS spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-methylquinoline] iridium(III) (thenoyltrifluoroacetonate): (btmq)2Ir(tta) (Ir1).

Figure S19 1H-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (btq)2Ir(tta) (Ir2).

Figure S20 13C-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (btq)2Ir(tta) (Ir2).

Figure S21 19F-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (btq)2Ir(tta) (Ir2).

Figure S22 MALDI TOF MASS spectrum of bis[2-(benzo[b]thiophen-2-yl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (btq)2Ir(tta) (Ir2).

Figure S23 1H-NMR spectrum of bis[ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate] iridium(III) (thenoyltrifluoroacetonate): (btecq)2Ir(tta) (Ir3).

Figure S24 13C-NMR spectrum of bis[ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate] iridium(III) (thenoyltrifluoroacetonate): (btecq)2Ir(tta) (Ir3).

Figure S25 19F-NMR spectrum of bis[ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate] iridium(III) (thenoyltrifluoroacetonate): (btecq)2Ir(tta) (Ir3).

Figure S26 MALDI TOF MASS spectrum of bis[ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate] iridium(III) (thenoyltrifluoroacetonate): (btecq)2Ir(tta) (Ir3).

Figure S27 1H-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (bttmq)2Ir(tta) (Ir4).

Figure S28 13C-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (bttmq)2Ir(tta) (Ir4).

Figure S29 19F-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (bttmq)2Ir(tta) (Ir4).

Figure S30 MALDI TOF MASS spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (bttmq)2Ir(tta) (Ir4).

Figure S31. Crystal packing structure of the complex Ir1 and Ir4 with intermolecular C–H…F interactions shown as (green) dashed lines. The solvent molecules not involved in intermolecular interactions have been omitted for clarity.

Figure S32 Thermogravimetric curves for complex Ir1 Ir4 under nitrogen atmosphere.

Figure S33 Differential scanning calorimetric curves for complex Ir1 Ir4 under N2 atmosphere

Figure S34 Optimized geometries of Ir1-Ir4 at the PBE1PBE/6-31G* level

Figure S35. Comparison of experimental (red line) and Calculated absorption spectra (TDDFT) for Ir1-Ir4. The vertical blue segments are the calculated absorption wavelengths and their size is proportional to the oscillator strength. The calculated spectral lines are the convolution of the transitions with a gaussian smearing of 0.15eV.

Figure S36. Optimized geometries of Ir1-Ir4 exhibits dipole moment at the PBE1PBE/6-31G* level

Figure S37. Cyclic voltammograms of redox processes of complexes Ir1−Ir4 (conditions: GC as working electrode, sweep rate ν = 100 mV/s, 0.2 M Bu4NPF6 in CH2Cl2 vs) Ag/AgCl.

Figure S38 Comparison of lifetime decay profiles of complex Ir1 ̶Ir4 in degassed dichloromethane solution (c = 2 × 10-5 M) and 5 wt% doped PMMA films at 298 K (λexc = 464 nm).

Figure S39. Comparison of experimental FT-IR Spectrum with the IR intensity obtained from the optimized triplet and singlet geometries of Ir1 and Ir2

Figure S40. Comparison of experimental FT-IR Spectrum with the IR intensity obtained from the optimized triplet and singlet geometries of Ir3 and Ir4

Figure S41 Electroluminescence spectra of (a) Ir1, (b) Ir2, (c) Ir3, and (d) Ir4-based PhOLEDs as a function of applied voltages during operation.

Figure S42 Two-dimensional (top) and three-dimensional (bottom) AFM images of (a) Ir1, (b) Ir2, (c) Ir3, and (d) Ir4- doped TCTA:mCP cohost films. (Scan sizes are 3x3 µm for all films).

Table S1 Selected Bond Lengths for Complexes Ir1- Ir4

Table S2 Selected Bond Angles for Ir1 and Ir2

Table S3 Selected Bond Angles for Ir3 and Ir4

Table S4. Selected bond distances, bond angles and dihedral angles from the optimized ground (S0) and triplet state (T1) geometry for the complexes Ir1-Ir4 together with the experimental values.

Table S5. HOMO-2, HOMO-1, HOMO, LUMO, LUMO+1 and LUMO+2 contour plots of Ir1-Ir4 at the PBE1PBE/6-31G* level

Table S6 Calculated energy levels of the HOMO, HOMO-1, HOMO-2, LUMO, LUMO+1, and

LUMO+2 and percentage of contribution of iridium metal (Ir), benzothiophenequinolinate

derivatives and thenoyltrifluoroacetonate (TTA) ligands.

Table S7 Calculated Absorption of Ir1-Ir4 in CH2Cl2 Media at TD-B3LYP Level together with Experimental Values

EXPERIMENTAL SECTIONMaterials and physical measurements. A 400 MHz Bruker NMR spectrometer was used to

record the 1H, 19F and 13C NMR spectra of the iridium(III) complex in CDCl3 solution. The

chemical shifts (δ) of the signals are given in ppm and referenced to the internal standard

tetramethylsilane [Si(CH3)4]. The signals splitting is abbreviated as follows: s = singlet; d =

doublet; t = triplet; dd = doublet of doublets; dq = doublet of quintets; td = triplet of doublets; dd

= doublet of doublet of doublets; m = multiplet. Coupling constants (J) are given in Hertz (Hz).

Magnesium sulphate (anhydrous), sodium carbonate, sodium hydroxide,

tetrakis(triphenylphosphine) palladium(0), IrCl3·x(H2O), 4-trifluoromethyl-2 (1H) -quinolinone,

2-hydroxyquinoline-4-carboxylic acid, POCl3, thionyl chloride, 2-bromoquinoline, 2-chloro-4-

methylquinoline, benzo[b]thiophene-2-boronic acid and 4,4,4-trifluoro-1-(2-thienyl)-1,3-

butanedione were employed in the synthesis of the iridium(III) complex (Ir1-Ir4). These

chemicals were purchased from Sigma Aldrich and were used without any further purification.

The cyclometalated ligand, namely, 2-(2,4-difluorophenyl)-4-formylpyridine was synthesized for

the first time and fully characterized. The synthesis of the iridium dimer complex [(C∧N)2Ir(μ-

Cl)]2 was carried out by a standard procedure proposed by Watts and co-workers,1 using

IrCl3·x(H2O) and cyclometalating ligands (L1, L2, L3 and L4) in a mixture of 2-ethoxyethanol

and water. The cyclometalated ligands, namely, 2-(benzo[b]thiophen-2-yl)-4-methylquinoline

(L1), 2-(benzo[b]thiophen-2-yl)quinoline (L2), ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-

carboxylate (L3), 2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline (L4) and precursor

compounds for L3 and L4 namely, ethyl 2-chloroquinoline-4-carboxylate (L3a) and 2-chloro-4-

(trifluoromethyl)quinoline (L4a) were freshly synthesized and fully characterized. Thin-layer

chromatography (TLC) was used to monitor the reaction progress (silica gel 60 F254, Merck

Co.) and the spots were observed under UV light at 254 and 365 nm. Silica column

chromatography was performed using silica gel (230–400 mesh, Merck Co.). The dry solvents

are purified using J.C. Metyer solvent drying system. All other reagents are of analytical grade

and used as received from Aldrich, Alfa Aesar and Samchun chemicals unless otherwise

specified.

Thermal analysis. Thermo-gravimetric analyses were performed on an TG/DTA Q500 (TA

Instrument) heated from 30 to 900˚C in flowing of nitrogen at the heating rate of 10 ˚C min-1.

Temperature at which a 5% weight loss occurred has been considered as the decomposition

temperature (Td). Differential scanning calorimetry was performed using a Perkin-Elmer Pyris

DSC 4000 instrument in sealed aluminum pans under nitrogen flow at a heat/cooling rate of

5˚C/min. The endothermic peak observed in the second heating cycle has been considered as the

glass transition temperature (Tg).

Cyclic voltammetry. Cyclic voltammetry experiments were carried out with a PowerLab/AD

instrument model system using three electrode cell assemblies. Platinum wires were used for

counter electrodes, a silver wire was used as Ag/Ag+ quasi reference electrode and a platinum

electrode was used as a working electrode. Measurements were carried out in dichloromethane

solution with tetrabutylammonium hexafluorophosphate as supporting electrolyte at a scan rate

of 100 mV/s. Concentrations of iridium(III) complex and supporting electrolyte were 5×10-3 and

0.2 M, respectively. The ferrocenium/ferrocene couple (FeCp2+/FeCp2

0) was used as an internal

reference. The energy level of FeCp2+/FeCp2

0 was assumed at –4.8 eV to vacuum.2 All solutions

for the electrochemical studies were deaerated with pre-purified argon gas prior to the

measurements.

Computational methods. The geometrical structures of the singlet ground state (S0) and the

lowest lying triplet excited state (T1) were optimized by using density functional theory (DFT)

based on a method with Perdew-Burke-Ernzerhof (PBE0) hybrid functional with LANL2DZ

basis set for the Iridium (Ir) atom and 6-31G* for the rest of the atoms. Frequency calculations

were also executed at the same level of theory. The optimizations and the vibrational data

confirmed that the structures were true minima on the potential energy surface because there

were no imaginary frequencies. On the basis of the optimized ground and excited state geometry

structures, the absorption spectral properties in dichloromethane media were calculated by time-

dependent density functional theory (TD-DFT) approach with B3LYP/6-31G*. As solvent

effects are known to play a crucial role in predicting the absorption and emission spectra, the

same was incorporated in the TD-DFT calculations within the PCM framework. The Swizard

program has been employed to evaluate the contribution of singly excited state configurations to

each electronic transition.3 All calculations were carried out with Gaussian 16 package.4

Photophysical characterization. The electronic absorption spectrum of the complex was

measured on a Mecasys Optizen Pop UV/vis spectrophotometer. The photoluminescence (PL)

spectrum of the iridium(III) complex was recorded on a spectrofluorimeter (FP-6500, JASCO).

Emission and excitation spectra were corrected for source intensity (lamp and grating) by

standard correction curves. Phosphorescence lifetimes were measured using time correlated

single photon counting (TCSPC) system (HAMAMATSU/C11367-31). The luminescence

quantum efficiencies in the solution as well as film states were calculated by Quantaurus-QY

Absolute PL quantum yield spectrometer (C11347-11).

Surface morphology characterization. The topographies of tris(4-carbazoyl-9-

ylphenyl)amine (TCTA) and 1,3-Bis(N-carbazolyl)benzene (mCP) cohost films with Ir complex

dopants (Ir1-Ir4) were analyzed using atomic force microscopy (AFM; VEECO Dimension

3100+Nanoscope V) in the non-contact mode.

PhOLED device fabrication. The poly(3,4-ethylenedioxy thiophene) polystyrene sulfonate

(PEDOT:PSS, Al4083), tris(4-carbazoyl-9-ylphenyl)amine (TCTA), and 1,3-Bis(N-

carbazolyl)benzene (mCP) with sublime grade (>99.8 %) were purchased from Ossila Co. 1,3,5-

Tris(1-phenyl-1Hbenzimidazol-2yl)benzene (TPBi) was purchased from Lumtec Co. To

fabricate devices, the ITO-coated glass was used as an anode and sequentially cleaned with

deionized water, acetone, and isopropyl alcohol for 15 min in an ultrasonic bath, and dried in the

70 oC for one day. The ITO substrate was treated under O2 plasma for 60 s. The hole transport

layer of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS, 40 nm) was spin-

coated with 3000 rpm for 60 s and annealed at 150 oC for 15 min to remove the residual solvent.

The samples were moved into a nitrogen glove-box for coating the emitting material layers

(EML). To achieve red emission, Ir complex dopants (Ir1-Ir4) were spin-coated with 10 wt.%

ratio during the emitting material coating consisting with TCTA:mCP cohost. The TCTA, mCP,

and Ir complex dopants were respectively dissolved in chlorobenzene, and then the materials

were blended before spin-coating process. The emitting materials were spin-coated with 2000

rpm on the PEDOT:PSS, and annealed at 70 oC for 40 min. The electron transporting layer

(ETL) was vacuum-deposited TPBi (30 nm), 8-hydroxyquinolatolithium (Liq, 1 nm), and

aluminum (Al, 120 nm) were continuously evaporated, and were used as ETL, interlayer, and

cathode, respectively. Current density, luminance, and efficiencies versus driving voltage of

PhOLEDs were measured using the Keithley 236 and CS-1000 (Konica Minolta Co.) system.

The device area was 2 mm2 for all samples in this work. Electroluminescence (EL) spectra and

CIE coordinate were measured using CS-1000 spectoradiometer. For comparison of charge

carrier transport ability, the hole-only devices (HODs) and electron-only devices (EODs) were

fabricated as follows:

HOD : ITO/PEDOT:PSS (40nm)/TCTA:mCP:Ir complexes/Ag

EOD : Al/LiF (1nm)/TCTA:mCP:Ir complexes/LiF (1nm)/Al

Solution processes are same condition Current density versus driving voltage of HOD and

EOD samples were measured using the Keithley 4200 SCS system and the device active area

was 2 mm2 for all samples.

Figure S1 1H-NMR spectrum of ethyl 2-chloroquinoline-4-carboxylate (L3a).

Figure S2 13C-NMR spectrum of ethyl 2-chloroquinoline-4-carboxylate (L3a).

Figure S3 1H-NMR spectrum of 2-chloro-4-(trifluoromethyl)quinoline (L4a)

Figure S4 13C-NMR spectrum of 2-chloro-4-(trifluoromethyl)quinoline (L4a)

Figure S5 19F-NMR spectrum of 2-chlro-4-(trifluoromethyl)quinoline (L4a)

Figure S6 1H-NMR spectrum of 2-(benzo[b]thiophen-2-yl)-4-methylquinoline [btmq] (L1).

Figure S7 13C-NMR spectrum of 2-(benzo[b]thiophen-2-yl)-4-methylquinoline [btmq] (L1).

Figure S8 1H-NMR spectrum of 2-(benzo[b]thiophen-2-yl)quinoline [btq] (L2).

Figure S9 13C-NMR spectrum of 2-(benzo[b]thiophen-2-yl)quinoline [btq] (L2).

Figure S10 1H-NMR spectrum of ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate [btecq] (L3).

Figure S11 13C-NMR spectrum of ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate [btecq] (L3).

Figure S12 1H-NMR spectrum of 2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline [bttmq] (L4).

Figure S13 13C-NMR spectrum of 2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline [bttmq] (L4).

Figure S14 19F-NMR spectrum of 2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline [bttmq] (L4).

Figure S15 1H-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-methylquinoline] iridium(III) (thenoyltrifluoroacetonate): (btmq)2Ir(tta) (Ir1).

Figure S16 13C-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-methylquinoline] iridium(III) (thenoyltrifluoroacetonate): (btmq)2Ir(tta) (Ir1).

Figure S17 19F-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-methylquinoline] iridium(III) (thenoyltrifluoroacetonate): (btmq)2Ir(tta) (Ir1).

Figure S18 MALDI TOF MASS spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-methylquinoline] iridium(III) (thenoyltrifluoroacetonate): (btmq)2Ir(tta) (Ir1).

Figure S19 1H-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (btq)2Ir(tta) (Ir2).

Figure S20 13C-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (btq)2Ir(tta) (Ir2).

Figure S21 19F-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (btq)2Ir(tta) (Ir2).

Figure S22 MALDI TOF MASS spectrum of bis[2-(benzo[b]thiophen-2-yl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (btq)2Ir(tta) (Ir2).

Figure S23 1H-NMR spectrum of bis[ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate] iridium(III) (thenoyltrifluoroacetonate): (btecq)2Ir(tta) (Ir3).

Figure S24 13C-NMR spectrum of bis[ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate] iridium(III) (thenoyltrifluoroacetonate): (btecq)2Ir(tta) (Ir3).

Figure S25 19F-NMR spectrum of bis[ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate] iridium(III) (thenoyltrifluoroacetonate): (btecq)2Ir(tta) (Ir3).

Figure S26 MALDI TOF MASS spectrum of bis[ethyl 2-(benzo[b]thiophen-2-yl)quinoline-4-carboxylate] iridium(III) (thenoyltrifluoroacetonate): (btecq)2Ir(tta) (Ir3).

Figure S27 1H-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (bttmq)2Ir(tta) (Ir4).

Figure S28 13C-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (bttmq)2Ir(tta) (Ir4).

Figure S29 19F-NMR spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (bttmq)2Ir(tta) (Ir4).

Figure S30 MALDI TOF MASS spectrum of bis[2-(benzo[b]thiophen-2-yl)-4-(trifluoromethyl)quinoline] iridium(III) (thenoyltrifluoroacetonate): (bttmq)2Ir(tta) (Ir4).

Figure S31 Crystal packing structure of the complex Ir1 (a) and Ir4 (b) with intermolecular C–H…F interactions shown as (green) dashed lines. The solvent molecules not involved in intermolecular interactions have been omitted for clarity.

Figure S32 Thermogravimetric curves for complex Ir1 Ir4 under nitrogen atmosphere.

Figure S33 Differential scanning calorimetric curves for complex Ir1 Ir4 under N2 atmosphere

Ir1 Ir2

Ir3 Ir4

Figure S34 Optimized geometries of Ir1-Ir4 at the PBE1PBE/6-31G* level

Figure S35 Comparison of experimental (red line) and Calculated absorption spectra (TDDFT) for Ir1-Ir4. The vertical blue segments are the calculated absorption wavelengths and their size is proportional to the oscillator strength. The calculated spectral lines are the convolution of the transitions with a gaussian smearing of 0.15eV.

5.7109 D 5.6282 D 8.6804 D 5.4941 DIr1 Ir2 Ir3 Ir4

Figure S36 Optimized geometries of Ir1-Ir4 exhibits dipole moment at the PBE1PBE/6-31G* level

Figure S37 Cyclic voltammogramms of redox processes of complexes Ir1−Ir4 (conditions: GC as working electrode, sweep rate ν = 100 mV/s, 0.2 M Bu4NPF6 in CH2Cl2 vs) Ag/AgCl.

Figure S38 Comparison of lifetime decay profiles of complex Ir1 Ir4 in degassed dichloromethane solution (c = 2 × 10-5 M) and 5 wt% doped PMMA films at 298 K (λexc = 464 nm).

Figure S39 Comparison of experimental FT-IR Spectrum with the IR intensity obtained from the optimized triplet and singlet geometries of Ir1 and Ir2

Figure S40 Comparison of experimental FT-IR Spectrum with the IR intensity obtained from the optimized triplet and singlet geometries of Ir3 and Ir4

Figure S41 Electroluminescence spectra of (a) Ir1, (b) Ir2, (c) Ir3, and (d) Ir4-based PhOLEDs as a function of applied voltages during operation.

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Figure S42 Two-dimensional (top) and three-dimensional (bottom) AFM images of (a) Ir1, (b) Ir2, (c) Ir3, and (d) Ir4 doped TCTA:mCP cohost films. (Scan sizes are 3x3 µm for all films).

Table S1 Selected Bond Lengths for Complexes Ir1-Ir4

Selected bond lengths for Ir1 (Å) Number Atom1 Atom2 Length

1 C20 Ir1 1.975 (7)2 C28 Ir1 1.970 (9)3 N1 Ir1 2.086 (8)4 N2 Ir1 2.101 (8)5 O1 Ir1 2.136 (6)6 O2 Ir1 2.145 (7)

Selected bond lengths for Ir2 (Å)1 C19 Ir1 1.973 (9)2 C36 Ir1 1.960 (9)3 N1 Ir1 2.060 (7)4 N2 Ir1 2.065 (7)5 O1 Ir1 2.113 (7)6 O2 Ir1 2.159 (7)

Selected bond lengths for Ir3 (Å) 1 C13 Ir1 1.977 (8)2 C33 Ir1 1.960 (1)3 N1 Ir1 2.089 (7)4 N2 Ir1 2.074 (7)5 O5 Ir1 2.144 (6)6 O6 Ir1 2.128 (7)

Selected bond lengths for Ir3 (Å)1 C19 Ir1 1.979 (3)2 C37 Ir1 1.980 (3)3 O1 Ir1 2.148 (2)4 O2 Ir1 2.150 (2)5 N1 Ir1 2.094 (3)6 N2 Ir1 2.082 (3)

Table S2 Selected Bond Angles for Ir1 and Ir2

Selected bond angles for Ir1 (˚) Selected bond angles for Ir2 (˚)Number Atom1 Atom2 Atom3 Angle Number Atom1 Atom2 Atom3 Angle

1 C20 Ir1 C28 97.5 (3) 1 C19 Ir1 C36 93.2 (4)2 C20 Ir1 N1 80.1 (3) 2 C19 Ir1 N1 80.5 (3)3 C20 Ir1 N2 99.4 (3) 3 C19 Ir1 N2 99.4 (3)4 C20 Ir1 O1 174.9 (3) 4 C19 Ir1 O1 90.2 (3)5 C20 Ir1 O2 88.6 (3) 5 C19 Ir1 O2 175.9 (3)6 C28 Ir1 N1 99.3 (3) 6 C36 Ir1 N1 100.3 (3)7 C28 Ir1 N2 80.2 (3) 7 C36 Ir1 N2 79.6 (3)8 C28 Ir1 O1 87.4 (3) 8 C36 Ir1 O1 176.4 (3)9 C28 Ir1 O2 173.6 (3) 9 C36 Ir1 O2 90.4 (3)10 N1 Ir1 N2 179.2 (3) 10 N1 Ir1 N2 179.8 (3)11 N1 Ir1 O1 97.6 (3) 11 N1 Ir1 O1 81.3 (3)12 N1 Ir1 O2 83.5 (3) 12 N1 Ir1 O2 100.7 (3)13 N2 Ir1 O1 82.9 (3) 13 N2 Ir1 O1 98.8 (3)14 N2 Ir1 O2 97.1 (3) 14 N2 Ir1 O2 79.4 (3)15 O1 Ir1 O2 86.6 (2) 15 O1 Ir1 O2 86.1 (3)

Table S3 Selected Bond Angles for Ir3 and Ir4

Selected bond angles for Ir3 (˚) Selected bond angles for Ir4 (˚)Number Atom1 Atom2 Atom3 Angle Number Atom1 Atom2 Atom3 Angle

1 C13 Ir1 C33 95.7 (4) 1 C19 Ir1 C37 94.6 (1)2 C13 Ir1 N1 80.1 (3) 2 C19 Ir1 O1 89.0 (1)3 C13 Ir1 N2 99.7 (3) 3 C19 Ir1 O2 175.4 (1)4 C13 Ir1 O5 175.8 (3) 4 C19 Ir1 N1 79.9 (1)5 C13 Ir1 O6 89.7 (3) 5 C19 Ir1 N2 98.9 (1)6 C33 Ir1 N1 101.6 (3) 6 C37 Ir1 O1 176.0 (1)7 C33 Ir1 N2 80.5 (3) 7 C37 Ir1 O2 89.9 (1)8 C33 Ir1 O5 88.5 (3) 8 C37 Ir1 N1 101.0 (1)9 C33 Ir1 O6 174.5 (3) 9 C37 Ir1 N2 79.8 (1)10 N1 Ir1 N2 177.9 (3) 10 O1 Ir1 O2 86.56 (8)11 N1 Ir1 O5 99.2 (2) 11 O1 Ir1 N1 77.98 (9)12 N1 Ir1 O6 78.5 (2) 12 O1 Ir1 N2 101.31 (9)13 N2 Ir1 O5 80.8 (2) 13 O2 Ir1 N1 100.53 (9)14 N2 Ir1 O6 99.4 (2) 14 O2 Ir1 N2 80.60 (9)15 O5 Ir1 O6 86.1 (2) 15 N1 Ir1 N2 178.6 (1)

Table S4. Selected bond distances, bond angles and dihedral angles from the optimized ground (s0) and triplet state (t1) geometry for the complexes Ir1-Ir4 together with the experimental values.

Ir1 Ir2 Ir3 Ir4S0 T1 Exp S0 T1 Exp S0 T1 Exp S0 T1 Exp

Bond length (Å)Ir-O1 2.15528 2.11576 2.145 2.15492 2.11375 2.159 2.15328 2.16276 2.128 2.14905 2.16157 2.148Ir-O2 2.15693 2.06156 2.136 2.15691 2.06003 2.113 2.15520 2.15214 2.144 2.15463 2.15195 2.150Ir-N1 2.07889 2.08585 2.101 2.07917 2.08522 2.065 2.07519 2.05940 2.074 2.07280 2.05683 2.094Ir-N2 2.07810 2.08034 2.086 2.07611 2.08002 2.060 2.07375 2.08536 2.089 2.07238 2.08473 2.082Ir-C1 1.98156 1.98855 1.970 1.98126 1.98929 1.960 1.98165 1.95249 1.977 1.97971 1.95453 1.979Ir-C5 1.98085 1.98314 1.975 1.98083 1.98296 1.973 1.98067 1.97875 1.964 1.98005 1.97862 1.980

Bond angle(deg)N1-Ir-C1 80.472 81.010 80.18 80.595 81.064 79.58 80.642 81.458 80.55 80.674 81.603 79.93N2-Ir-C5 80.497 80.968 80.13 80.612 81.074 80.45 80.660 100.051 101.58 80.694 80.814 79.77O1-Ir-O2 84.781 84.682 86.55 84.843 84.537 86.09 84.775 84.283 86.11 84.427 84.233 86.56N1-Ir-N2 179.039 178.669 179.23 178.876 178.577 179.85 178.703 177.947 177.87 178.951 177.994 178.60C5-Ir-O1 174.154 178.280 174.87 173.925 178.440 175.92 174.152 174.718 174.54 174.083 175.008 176.04C1-Ir-O2 174.642 171.589 173.63 174.739 171.303 176.40 174.552 174.843 175.82 174.096 174.406 175.37

Interligand Angle (deg)

N1-Ir-O1 80.301 79.707 97.11 80.194 79.923 79.44 80.113 79.973 99.39 80.574 80.142 77.98N1-Ir-C5 100.386 100.309 80.18 100.473 100.288 99.42 100.515 100.051 101.58 100.205 99.866 101.01

Dihedral Angle (deg)

C1-C2-C3-C4 179.831 177.585 179.20 179.981 178.403 179.44 179.031 177.919 178.37 179.453 178.347 179.89C5-C6-C7-C8 178.949 179.716 177.46 178.399 179.372 178.66 179.127 179.904 176.20 179.107 179.933 178.23

Table S5. HOMO-2, HOMO-1, HOMO, LUMO, LUMO+1 and LUMO+2 contour plots of Ir1-Ir4 at the PBE1PBE/6-31G* level

HOMO-2 HOMO-1 HOMO LUMO LUMO+1 LUMO+2

Ir1

Ir2

Ir3

Ir4

Table S6 Calculated energy levels of the HOMO, HOMO-1, HOMO-2, LUMO, LUMO+1, and LUMO+2 and percentage of contribution of

iridium metal (Ir), benzothiophenequinolinate derivatives and thenoyltrifluoroacetonate (TTA) ligands.

Complex Orbital E (eV) Iridium Substituted Quinolinate moiety Benzothiophene moiety Ancillary (TTA)Ir1 HOMO-3 -6.124 10.38 21.55 65.34 2.73

HOMO-2 -5.893 39.85 16.57 22.78 20.8HOMO-1 -5.605 1.58 26.82 70.74 0.86HOMO -5.037 27.1 18.22 52.83 1.85LUMO -2.331 2.58 4.31 2.42 90.69LUMO+1 -2.076 6.48 69.39 21.43 2.7LUMO+2 -2.026 6.24 70.8 20.71 2.25LUMO+3 -1.054 1.44 70.8 26.93 0.82

Ir2 HOMO-3 -5.941 8.28 19.41 69.12 3.18HOMO-2 -5.759 38.61 15.15 24.39 21.85HOMO-1 -5.426 1.4 25.88 71.83 0.88HOMO -4.861 26.81 18.24 53.13 1.83LUMO -2.226 2.6 4.66 2.51 90.23LUMO+1 -1.998 6.67 68.63 21.38 3.32LUMO+2 -1.939 6.59 70.14 20.87 2.4LUMO+3 -1.004 1.42 70.35 27.46 0.78

Ir3 HOMO-3 -6.004 7.46 20.2 66.86 5.47HOMO-2 -5.862 32.66 15.12 31.16 21.05HOMO-1 -5.499 1.2 26.07 71.86 0.87HOMO -4.957 25.65 19.06 53.59 1.7LUMO -2.536 5.82 80.02 11.26 2.9LUMO+1 -2.43 6.51 79.64 10.32 3.53LUMO+2 -2.276 2.67 5.89 2.56 88.87LUMO+3 -1.23 2.41 54.95 41.75 0.89

Ir4 HOMO-3 -6.234 5.92 18.3 71.2 4.58HOMO-2 -6.081 31.6 12.24 32.08 24.07HOMO-1 -5.729 1.37 25.09 72.65 0.89HOMO -5.195 25.23 19.2 53.89 1.68LUMO -2.571 6.28 69.03 15.33 9.35

LUMO+1 -2.486 6.45 66.97 13.66 12.92LUMO+2 -2.438 3.65 17.19 5.03 74.13LUMO+3 -1.412 1.62 66.46 31.19 0.73

Table S7 Calculated Absorption of Ir1-Ir4 in CH2Cl2 Media at TD-B3LYP Level together with Experimental Values

State λ(nm)/E(eV) Oscillator Main configuration Assign λexp (nm)

Ir1 S1(triplet) 657/1.88 f=0.0000 H→L+1 (60%) btp/ Ir → CH3Qn (ILCT/ MLCT/LLCT)S2(triplet) 650/1.90 f=0.0000 H→L+2 (60%) btp/ Ir → CH3Qn (ILCT/ MLCT) 642S4(singlet) 596/2.07 f=0.0033 H→L (70%) btp/ Ir → tta (MLCT/ LLCT)S6(singlet) 519/2.38 f=0.0607 H→L+1 (62%) btp/ Ir → CH3Qn (MLCT/ LLCT/ILCT) 525S7(singlet) 516/2.39 f=0.1212 H→L+2 (62%) btp/ Ir → CH3Qn (ILCT/ MLCT/ LLCT) 522S11(singlet) 453/2.73 f=0.0001 H-1→L (69%) btp → tta (LLCT)S15(singlet) 424/2.92 f=0.0091 H-2→L (67%) btp/ Ir → tta (MLCT/LLCT)S16(singlet) 411/3.01 f=0.1216 H-1→L+1 (65%) btp → CH3Qn (LLCT) 405S17(singlet) 406/3.04 f=0.0746 H-1→L+2 (69%) btp → CH3Qn (ILCT) 399S18(singlet) 398/3.11 f=0.1481 H-2→L+1 (64%) btp/ Ir → CH3Qn (ILCT/ MLCT/ LLCT) 405S19(singlet) 392/3.15 f=0.0H-1 H-3→L (48%) btp/ Ir → tta (MLCT/ LLCT)S20(singlet) 384/3.22 f=0.0062 H-2→L+2 (47%) btp/ Ir → CH3Qn (MLCT/ LLCT)

Ir2 S1(triplet) 664/1.86 f=0.00001 H→L+1 (59%) btp/ Ir → Qn (ILCT/ MLCT/ LLCT) 650S2(triplet) 656/1.88 f=0.00001 H→L+2 (59%) btp/ Ir → Qn (ILCT/ MLCT/ LLCT)S4(singlet) 591/2.09 f=0.0030 H→L (70%) btp/ Ir → tta (ILCT/ MLCT/ LLCT)S6(singlet) 524/2.36 f=0.0502 H→L+1 (64%) btp/ Ir → Qn (ILCT/ MLCT/ LLCT) 524S7(singlet) 520/2.38 f=0.1152 H→L+2 (64%) btp/ Ir → Qn (ILCT/ MLCT/ LLCT) 520S11(singlet) 451/2.74 f=0.0004 H-1→L (69%) btp → tta (LLCT)S15(singlet) 420/2.95 f=0.0068 H-2→L (67%) btp/ tta/ Ir → tta (ILCT/ MLCT/ LLCT)S16(singlet) 414/2.99 f=0.1367 H-1→L+1 (66%) btp → Qn (ILCT/ LLCT)S17(singlet) 409/3.02 f=0.0705 H-1→L+2 (69%) btp → Qn (ILCT/ LLCT) 410S18(singlet) 407/3.04 f=0.0975 H-2→L+1 (65%) btp/ tta/ Ir → Qn (ILCT/ MLCT/ LLCT) 401S19(singlet) 400/3.09 f=0.0168 H-2→L+2 (55%) btp/ tta/ Ir → Qn (ILCT/ MLCT/ LLCT)S20(singlet) 391/3.17 f=0.0091 H-3→L (53%) btp/ Ir → tta (ILCT/ MLCT/ LLCT)

Ir3 S1(triplet) 797/1.55 f=0.00001 H→L (64%) btp/ Ir → COOEtQn (ILCT/ MLCT/ LLCT) 724S2(triplet) 771/1.60 f=0.00001 H→L+1 (62%) btp/ Ir → COOEtQn (ILCT/ MLCT/ LLCT)S3(singlet) 641/1.93 f=0.0214 H→L (69%) btp/ Ir → COOEtQn (ILCT/ MLCT/ LLCT) 633S4(singlet) 619/2.00 f=0.0988 H→L+1 (69%) btp/ Ir → COOEtQn (ILCT/ MLCT/ LLCT) 616S7(singlet) 567/2.18 f=0.0104 H→L+2 (69%) btp/ Ir → tta (MLCT/ LLCT) 573

S12(singlet) 488/2.53 f=0.0791 H-1→L (69%) btp → COOEtQn (ILCT) 500S14(singlet) 474/2.61 f=0.0392 H-1→L+1 (70%) btp → COOEtQn (ILCT)S16(singlet) 455/2.72 f=0.1005 H-2→L (68%) btp/ tta/ Ir → COOEtQn (ILCT/ MLCT/ LLCT) 448S17(singlet) 442/2.80 f=0.0056 H-1→L+2 (69%) btp → tta (LLCT)S18(singlet) 433/2.86 f=0.0072 H-2→L+1 (65%) btp/ tta/ Ir → COOEtQn (ILCT/ MLCT/ LLCT)S19(singlet) 430/2.87 f=0.0382 H-3→L (60%) btp/ Ir → COOEtQn (ILCT/ MLCT/ LLCT)S20(singlet) 410/3.02 f=0.0515 H-2→L+2 (64%) btp/ tta/ Ir → tta (MLCT/ LLCT) 420

Ir4 S1(triplet) 745/1.66 f=0.00001 H→L (63%) btp/ Ir → CF3Qn (ILCT/ MLCT) 690S2(triplet) 729/1.70 f=0.00001 H→L+1 (61%) btp/ Ir → CF3Qn (ILCT/ MLCT/ LLCT)S3(singlet) 591/2.09 f=0.0118 H→L (69%) btp/ Ir → CF3Qn (ILCT/ MLCT/ LLCT)S4(singlet) 575/2.15 f=0.1181 H→L+1 (70%) btp/ Ir → CF3Qn (ILCT/ MLCT/ LLCT) 575S6(singlet) 554/2.23 f=0.0164 H→L+2 (69%) btp/ Ir → tta (ILCT/ MLCT/ LLCT)S13(singlet) 459/2.69 f=0.0967 H-1→L (69%) btp → CF3Qn (ILCT / LLCT) 460S14(singlet) 448/2.76 f=0.0488 H-1→L+1 (70%) btp → CF3Qn (ILCT / LLCT)S16(singlet) 436/2.84 f=0.0113 H-1→L+2 (69%) btp → tta (LLCT)S17(singlet) 433/2.85 f=0.0741 H-2→L (67%) btp/ Ir → CF3Qn (ILCT/ MLCT/ LLCT)S18(singlet) 414/2.98 f=0.0047 H-2→L+1 (64%) btp/ Ir → CF3Qn (ILCT/ MLCT/ LLCT)S19(singlet) 399/3.10 f=0.0328 H-2→L+2 (66%) btp/ Ir → tta (MLCT/ LLCT) 400S20(singlet) 391/3.16 f=0.0442 H-3→L (53%) btp/ Ir → CF3Qn (ILCT/ MLCT/ LLCT)

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