S1

Supplementary Information

Iridium Motif Linked Porphyrins for Efficient Light-driven

Hydrogen Evolution via Triplet State Stabilization of Porphyrin

Daniel Nnaemaka Tritton,a‡ Govardhana Babu Bodedla,a‡ Geliang Tang,b Jianzhang Zhao,b

Ken Chak-Shing Kwan,a Ken Cham-Fai Leung,a,* Wai-Yeung Wong,a,c,* and Xunjin Zhua,*

aDepartment of Chemistry, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong

Kong SAR (P. R. China).

bSchool of Chemical Engineering, Dalian University of Technology, Dalian, China

cDepartment of Applied Biology & Chemical Technology, The Hong Kong Polytechnic

University, Hong Kong, China; The Hong Kong Polytechnic University Shenzhen Research

Institute, Shenzhen, 518057, China

‡ D.N.T and G.B.B contributed equally to this work.

E-mail: cfleung@hkbu.edu.hk; wai-yeung.wong@polyu.edu.hk and xjzhu@hkbu.edu.hk

Experimental Section

Materials and Methods

All the chemicals used in this work were purchased from commercial sources and used as

received. Solvents were dried by distilling over suitable dehydrating agents according to the

standard procedures. Purification of the compounds was performed by column

chromatography with 100-200 mesh silica. 1H and 13C NMR spectra recorded in a Bruker

NMR spectrometer operating at 400 and 101 MHz respectively. The chemical shifts were

calibrated from the residual peaks observed for the deuterated solvents chloroform (CDCl3) at

δ 7.26 ppm for 1H and δ 77.0 ppm for 13C, respectively and acetone ((CD3)2CO) at δ 2.05

ppm for 1H. High-resolution matrix-assisted laser desorption/ionization time-of-flight

Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A.This journal is © The Royal Society of Chemistry 2019

S2

(MALDI-TOF) mass spectra were obtained with a Bruker Autoflex MALDI-TOF mass

spectrometer. The optical absorption and emission spectra of the porphyrins were measured

for the freshly prepared air equilibrated solutions at room temperature by using UV-Vis

spectrophotometer and spectrofluorimeter, respectively. Cyclic voltammetry (CV) was

recorded on an electrochemical workstation in acetonitrile (MeCN) solution by using 0.1 M

tetrabutylammonium hexafluorophosphate (TBAPF6) as supporting electrolyte. The

experiments were performed at room temperature with a conventional three-electrode cell

assembly consisting of a platinum wire as auxiliary electrode, a non-aqueous Ag/AgNO3

reference electrode, ferrocene as internal standard and a glassy carbon working electrode.

Relative photoluminescence quantum yields (PL)

Relative luminescence quantum yields in the solution state were measured by the optical

dilute method reported by Demas and Crosby.1 A degassed solution of [Ru(bpy)3]Cl2 in

CH3CN solution (lum = 0.06, excitation wavelength at 436 nm) was used as the reference.2

The absorbance of the sample and reference solutions was measured by keeping them at 0.1

and the emission of the sample and reference solutions was recorded at 436 nm excitation

wavelength. The PL was calculated according to the following equation (Eq. 1):

(1)Ф𝐹

𝑠𝑎𝑚𝑝𝑙𝑒 = Ф𝐹𝑟𝑒𝑓(𝑆 𝑠𝑎𝑚𝑝𝑙𝑒

𝑆 𝑟𝑒𝑓)( 𝐴 𝑟𝑒𝑓

𝐴 𝑠𝑎𝑚𝑝𝑙𝑒)(𝑛 𝑠𝑎𝑚𝑝𝑙𝑒

𝑛 𝑟𝑒𝑓2

2)where Aref, Sref, nref, and Asample, Ssample, nsample represent the absorbance at the excited

wavelength, integrated area under the photoluminescence curves and the solvent refractive

index of the standard and the sample solutions.

Transient absorption measurement

Transient absorption spectra and excited-state lifetimes were obtained using an Edinburgh

Instrument LP980KS transient absorption spectrometer equipped with R928P photomultiplier

tube and a Tektronix Model TDS-3012C (100 MHz, 1.25 GS s–1) digital oscilloscope. All

S3

solutions for photophysical studies were degassed on a high-vacuum line in a two-

compartment cell consisting of a 10-mL Pyrex bulb and a 1-cm path length quartz cuvette

and sealed from the atmosphere by a Bibby Rotaflo HP6 Teflon stopper. The solutions were

rigorously degassed with no less than four successive freeze-pump-thaw cycles. All

absorption data is shown in Table 2.

Preparation of photocatalytic systems

A multichannel photochemical reaction system fixed with OLED white light (PCX50B, 148.5

mW/cm2) was used as the light source. The photocatalytic hydrogen (H2) evolution

experiments were performed in a quartz vial reactor (20 mL) sealed with a rubber septum,

gas-closed system, at ambient temperature and pressure. Initially, the prepared sample (100

μM) was dissolved in a mixture of MeCN/H2O (2:1 v/v) and triethylamine (TEA) (0.8 M)

under constant stirring. Then, cobaloxime (CoPyCl) (0.4 mM) co-catalyst was added. The

suspension was purged with argon gas for 10 min to ensure anaerobic conditions and then it

was placed in a multichannel photochemical reaction system. After 5 hours of irradiation, the

released gas (400 μL) was collected by syringe from the headspace of the reactor and was

analyzed by gas chromatography (Shimadzu, GC-2014, Japan, with ultrapure Ar as a carrier

gas) equipped with a TDX-01(5 Å molecular sieve column) and a thermal conductivity

detector (TCD). Eventually, the total content of photocatalytic H2 evolution was calculated

according to the standard curve. Continuous stirring was applied to the whole process to keep

the photocatalyst particles in suspension state and to achieve uniform irradiation.

The apparent quantum efficiency (AQE) was measured under the similar

photocatalytic reaction conditions except using 420 nm OLED light. The focused

intensity and illuminated area LED light were ca. 68.0 mW/cm2 and 9.04 cm2,

respectively. AQE was calculated via the following equation:

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AQE = %(2 × 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 ℎ𝑦𝑑𝑟𝑜𝑔𝑒𝑛 𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑒𝑠 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑖𝑛𝑐𝑖𝑑𝑒𝑛𝑡 𝑝ℎ𝑜𝑡𝑜𝑛𝑠 ) × 100

The turnover number (TON) was calculated after 1 hour by using the following

formula;

TON =

𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑜𝑙𝑒𝑠 𝑜𝑓 ℎ𝑦𝑑𝑟𝑜𝑔𝑒𝑛 𝑝𝑟𝑜𝑑𝑢𝑐𝑒𝑑 𝑖𝑛 𝑝ℎ𝑜𝑡𝑜𝑐𝑎𝑡𝑎𝑙𝑦𝑡𝑖𝑐 𝑠𝑦𝑠𝑡𝑒𝑚𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑜𝑙𝑒𝑠 𝑜𝑓 𝑝ℎ𝑜𝑡𝑜𝑐𝑎𝑡𝑎𝑙𝑦𝑠𝑡

Photoelectrochemical Measurement

To get more insight into the photocatalytic electron transfer mechanism and consequently

ηH2, the transient photocurrent responses (I–t curves) studies were performed using an

electrochemical workstation (CHI660C Instruments, China) with Pt wire (counter electrode),

a non-aqueous Ag/AgNO3 (reference electrode) and fluorine-doped tin oxide (FTO) glass

coated with a porphyrins on the conductive surface (working electrode) upon irradiation of

LED monochromatic point lamp (3 W, 420 nm). The light spot effective area on the working

electrode was set as 28.26 mm2. Typically, the working electrode was prepared by dissolving

100 μM of porphyrins in 200 μL of chlorobenzene and then applied on the conductive surface

of FTO glass using drop dispense method. 5 mL volume of 0.5 M Na2SO4 aqueous solution

acted as the electrolyte. The open-circuit voltages were set as the initial bias voltages in the

transient photocurrent responses tests. As shown below in Fig S11, the Ir linked porphyrins

MBPyZnP-Ir and TBPyZnP-Ir exhibit a higher photocurrent response than their

corresponding analogues MBPyZnP and TBPyZnP containing no Ir motif. This indicates the

efficient photogenerated charge carrier’s separation and more electrons generated for the Ir

motif linked porphyrins. Especially, TBPyZnP-Ir exhibited the highest photocurrent

response in the series, further attesting to its higher PHE when it was employed as a

photosensitizer. All these results indicate that incorporation of the Ir motif to BPy zinc

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porphyrins is beneficial to improve the PHE by enhancing the photogenerated electrons and

their transfer from photo excited porphyrins to CoPyCl co-catalyst.

Synthesis

The bipyridyl aldehyde intermediate for preparation of the BPy poprhyrins, 4’-methyl-2,2’-

bipyridine-4-carbaldehyde was synthesized by a modified procedure to that of Araki et al.

and characterized by comparing the 1H NMR spectrum of the compound to that found in the

literature.3 The precursor C^N ligand for the iridium dimer, 2-phenyl-5-(trifluorophenyl)-

pyridine was synthesized by a modified procedure to that of Wang et al. and characterized by

comparing the 1H NMR spectrum of the compound to that found in the literature.4 The

cyclometalated iridium dimer intermediate, bis(2-phenyl-5-(trifluorophenyl)-pyridine)

iridium (III) dichloro-bridged dimer was synthesized by a modified procedure to that of Chen

et al. and characterized by comparing the 1H NMR spectrum of the compound to that found

in the literature.5

MBPyP: 4’-Methyl-2,2’-bipyridine-4-carbaldehyde (1.00 g, 5.04 mmol) and benzaldehyde

(2.14 g, 20.16 mmol) were dissolved in propionic acid (70 mL) and refluxed gently (140 –

150 oC) for 10 minutes. Pyrrole (1.60 μL, 23.18 mmol) was added to the reaction mixture,

which was refluxed in air for 4 hours, whilst covering with aluminum foil. Acid was removed

by distillation and porphyrin mixture was re-crystallised from MeOH and stored in fridge

overnight. Supernatant liquid was discarded and remaining black residue was dissolved in a

minimum amount of DCM and purified by silica gel column using pure DCM and several

drops of MeOH. Fractions were monitored by TLC (20:1 DCM: MeOH) and desired spot was

S6

N N N N

OHSeO2

1,4-dioxane,

HN

HN

+

OH

Propionic acid,

N

NH N

HNN

N N

NH N

HNN

N

N

N

N

N

N

NClIr Ir

Cl

N

CF3

N

CF3

2 2

MBpyP

Ir-dimerEthylene Glycol, H2O, NH4PF6

N

NH N

HNR

N

NH N

HN

R

R

R

R

N

N

Ir

NCF3

N

CF3

R =

MBPyPH2-Ir

N

N N

NR

MBPyZnP-Ir

Zn N

N N

N

R

R

R

RZn

Zn(OAc)2.2H2O, CHCl3,

TBPyP

TBPyPH2-Ir

TBPyZnP-Ir

reflux

reflux

Propionic acid,

reflux

MeOH, N2, reflux

Zn(OAc)2.2H2O, CHCl3,

MeOH, N2, reflux

PF6-

PF6-

(PF6-)44+

(PF6-)4

4+

Ir-dimerEthylene Glycol, H2O, NH4PF6

Ir-dimer

Scheme S1. Synthesis of MBPyZnP-Ir and TBPyZnP-Ir.

S7

collected, concentrated by rotary evaporation and vacuum dried to afford MBPyP (182.60

mg, 0.26 mmol, 5.13 % yield) as a dark reddish solid. 1H NMR (400 MHz, CDCl3, δ ppm):

9.23 (s, 1H), 9.01–9.00 (d, J = 4 Hz, 1H), 8.80–8.79 (d, J = 4 Hz, 7H), 8.45 (s, 1H), 8.44–

8.42 (d, J = 8 Hz, 1H), 8.15–8.13 (dd, J = 8 Hz, J = 8 Hz, 6H), 8.10–8.09 (dd, J = 4 Hz, J = 4

Hz, 1H), 7.80–7.78 (m, 1H), 7.70–7.67 (m, 8H), 7.62–7.60 (m, 1H), 7.11–7.10 (d, J = 4 Hz,

1H), 2.47 (s, 3H), ‒2.86 (s, 2H). 13C NMR (101 MHz, CDCl3, δ ppm): 155.92, 154.83,

151.51, 149.25, 148.35, 147.50, 142.07, 142.01, 139.19, 134.60, 133.91, 132.24, 131.21,

130.12, 129.52, 128.93, 128.43, 128.09, 127.82, 126.96, 126.74, 124.99, 122.60, 120.84,

120.51, 116.74, 29.73, 21.34 (Fig S11). MALDI - TOF: C49H34N6, 707.2917 (Calcd M+),

707.0474 (Found M+).

MBPyPH2-Ir: MBPyP (40.0 mg, 0.057 mmol) and bis(2-phenyl-5-(trifluorophenyl)-pyridine)

iridium (III) dichloro-bridged dimer (38.3 mg, 0.029 mmol) were dissolved in a 1:1 mixture

of ethylene glycol and water (20 mL each) and the mixture was refluxed in air overnight.

Reaction mixture was cooled to room temperature and transferred into a beaker containing

ice. NH4PF6 (aq) (15 mL) was added to mixture which was then stirred for 2 hours. Mixture

was extracted using DCM and lower organic layer was collected and dried using anhydrous

MgSO4; MgSO4 was added to mixture and stirred for 1 hour before collecting supernatant

liquid by suction filtration. Dried organic layer was collected and concentrated to afford a

dark red residue, before re-dissolving in DCM and purifying by silica gel column using 8:1

DCM: acetone. Fractions were monitored by TLC (using same system as column) and desired

spot was collected, concentrated by rotary evaporation and vacuum dried to afford

MBPyPH2-Ir (44.0 mg, 0.03 mmol, 51.9 % yield) as a dark red purplish solid. 1H NMR (400

MHz, acetone-D6, δ ppm): 9.73 (s, 1H), 9.06–8.89 (m, 7H), 8.67–8.60 (m, 5H), 8.50–8.42 (m,

4H), 8.27–8.22 (m, 7H), 8.18–8.13 (m, 3H), 7.90–7.84 (m, 8H), 7.78–7.75 (m, 1H), 7.69–

7.67 (d, J = 4 Hz, 1H), 7.19–7.15 (m, 2H), 7.12–7.08 (m, 2H), 6.65–6.63 (m, 1H), 6.54–6.52

S8

(m, 1H), 2.52 (s, 3H), ‒2.78 (s, 2H). 13C NMR spectrum could not be obtained for MBPyH2-

Ir. MALDI - TOF: C73H48F6IrN8, 1343.3536 (Calcd [M‒PF6]+), 1343.3587 (Found

[M‒PF6]+).

MBPyZnP-Ir: MBPyPH2-Ir (15.8 mg, 0.011 mmol) was dissolved in CHCl3 (30 mL) and

Zn(OAc)2.2H2O (23.3 mg, 0.11 mmol) was dissolved in MeOH (4 mL) and both were mixed;

the reaction mixture was stirred at 60 oC under N2 overnight. After cooling to room

temperature, the reaction mixture was concentrated, re-dissolved in CHCl3 (40 mL) and

washed with H2O (70 mL); organic layer was collected and dried by adding sodium sulphate

and stirring for 1 hour. Mixture was filtered and concentrated to afford a dark green solid,

before re-dissolving in CHCl3 and purifying by silica gel column using pure CHCl3. Fractions

were monitored by TLC (using pure DCM) and desired spot was collected, concentrated by

rotary evaporation and vacuum dried to afford MBPyZnP-Ir (13.4 mg, 0.0090 mmol, 81.5 %

yield) as a dark green crystalline solid. 1H NMR (400 MHz, acetone-D6, δ ppm): 10.07 (s,

1H), 9.47–9.29 (m, 8H), 9.08–8.89 (m, 8H), 8.65–8.57 (m, 10H), 8.24 (s, 9H), 8.09 (s, 1H),

7.59–7.52 (m, 4H), 7.07–6.97 (m, 2H), 2.95 (s, 3H). 13C NMR spectrum could not be

obtained for MBPyZnP-Ir. MALDI - TOF: C73H46F6IrN8Zn, 1405.2657 (Calcd [M–PF6]+),

1405.0349 (Found [M–PF6]+).

MBPyZnP: MBPyZnP was synthesized by the same procedure as described above for

MBPyZnP-Ir, except using MBPyP instead of MBPyPH2-Ir. MBPyZnP (15.6 mg, 0.02

mmol, 70.1 % yield) was afforded as a dark purple crystalline solid. 1H and 13C NMR spectra

could not be obtained for MBPyZnP. MALDI - TOF: C49H32N6Zn, 768.1974 (Calcd M+),

768.1932 (Found M+).

TBPyP: 4’-Methyl-2,2’-bipyridine-4-carbaldehyde (208.8 mg, 1.050 mmol) was dissolved in

propionic acid (70 mL) and refluxed gently (140 - 150 oC) for 10 minutes. Pyrrole (77 μL,

1.11 mmol) was added to reaction mixture and refluxed in air for 4 hours, whilst covering

S9

with aluminum foil. Propionic acid was removed by flushing with air overnight. Remaining

black precipitate was completely dissolved in CHCl3 and purified by silica gel column using

pure CHCl3 and a few drops of MeOH. Fractions were monitored by TLC (10:1 DCM:

MeOH) and desired spot was collected, concentrated by rotary evaporation and vacuum dried

to afford a black reddish precipitate. Solid was recrystallized from MeOH to afford TBPyP

(40.0 mg, 0.041 mmol, 3.9 % yield) as a dark reddish solid. 1H NMR (400 MHz, CDCl3, δ

ppm): 9.27 (s, 4H), 9.04–9.03 (d, J = 4 Hz, 4H), 8.87 (s, 7H), 8.49–8.44 (m, 9H), 8.11–8.10

(d, J = 4 Hz, 4H), 7.13 (s, 4H), 2.48 (s, 12H), ‒2.91 (s, 2H). 13C NMR (101 MHz, CDCl3, δ

ppm): 155.80, 155.02, 150.95, 149.30, 148.32, 147.60, 129.47, 126.91, 125.04, 122.57,

118.08, 21.33 (Fig S15). MALDI - TOF: C46H46N12, 983.4041 (Calcd M+), 983.2643 (Found

M+).

TBPyPH2-Ir: TBPyPH2-Ir was synthesized by the same procedure as described above for

MBPyPH2-Ir, except using TBPyP instead of MBPyP. TBPyPH2-Ir (64.8 mg, 0.016 mmol,

43.8 % yield) was isolated as a dark red purplish solid. 1H NMR (400 MHz, acetonde-D6, δ

ppm): 9.67 (s, 4H), 9.30–8.46 (m, 40H), 8.25–8.13 (m, 16H), 7.68 (s, 4H), 7.21–7.09 (m,

16H), 6.65–6.53 (m, 8H), 2.52 (s, 12H), ‒2.91 (s, 2H). 13C NMR could not be obtained for

TBPyPH2-Ir. MALDI - TOF: C160H102F24Ir4N20, 3964.5671 (Calcd [M–PF6]+), 3964.5739

(Found [M–PF6]+).

TBPyZnP-Ir: TBPyZnP-Ir was synthesized by the same procedure as for MBPyZnP-Ir,

except using TBPyPH2-Ir instead of MBPyPH2-Ir. TBPyZnP-Ir (23.1 mg, 0.0055 mmol,

80.0 % yield) was obtained as a dark green crystalline solid. 1H NMR (400 MHz, acetone-D6,

δ ppm): 9.92–9.77 (m, 4H), 9.19–8.50 (m, 40H), 8.26–8.14 (m, 16H), 7.70 (s, 4H), 7.21–7.20,

7.14–7.13 (m, 16H), 6.67–6.57 (m, 8H), 2.56–2.54 (d, J = 8 Hz, 12H). 13C NMR could not be

obtained for TBPyZnP-Ir. MALDI - TOF: C160H100F24Ir4N20Zn, 4027.4786 (Calcd [M–

PF6]+), 4027.4762 (Found [M–PF6]+).

S10

TBPyZnP: TBPyZnP was synthesized by the same procedure as for MBPyZnP-Ir, except

using TBPyP instead of MBPyP-Ir. TBPyZnP (25.3 mg, 0.024 mmol, 78.0 % yield) was

afforded as a dark purple crystalline solid. 1H and 13C NMR could not be obtained for

TBPyZnP. MALDI - TOF: C64H44N12Zn, 1044.3098 (Calcd M+), 1044.3086 (Found M+)

(Fig S23).

580 680 780

Norm

alize

d Em

issio

n In

tens

ity

Wavelength / nm

MBPyZnP-Degassed TBPyZnP-Degassed MBPyZnP-Aerated TBPyZnP-Aerated

Fig S1. Normalized emission spectra of aerated and degassed MBPyZnP and TBPyZnP in MeCN at room temperature.

-0.5 0.0 0.5 1.0 1.5 2.0

Inte

nsity

(a.u

.)

Time / ns

MBPyZnP ExpDec1

Model ExpDec1Equation y = A1*exp(-x/t1) + y0

Reduced Chi-Sqr

2.59583E-8

Adj. R-Squa 0.6923Value Standard Er

?$OP:F=1 y0 4.29137E 9.06951E-6?$OP:F=1 A1 8.19032 5.12625?$OP:F=1 t1 7.23746 0.56484

Fig S2. Emission decay profile for MBPyZnP in aerated MeCN monitored at 610 nm.

S11

0 4 8 12 16

Inte

nsity

(a.u

.)

Time / ns

MBPyZnP ExpDec2

Model ExpDec2Equation y = A1*exp(-x/t1) + A2*exp(-x/t2) + y0

Reduced Chi-Sqr

2.634E-9

Adj. R-Squar 0.97922Value Standard Err

?$OP:F=1 y0 1.74965E- 3.42762E-6?$OP:F=1 A1 0.00809 7.18843E-5?$OP:F=1 t1 233.07519 1.43417?$OP:F=1 A2 7.64697E- 2.88394E-6?$OP:F=1 t2 6379.0255 90.54738

Fig S3. Emission decay profile for MBPyZnP in degassed MeCN monitored at 610 nm.

2.23 eV

3.08 eV

3.23 eV

3.48 eV

S0

S4

S3

S2

S1

T11.55 eV

ISC

2.02 eVT2

2.17 eV*S1

IC

IC

Abs Em

Fig S4. Jablonski energy diagram of MBPyZnP based on the computation at

B3LYP/GENECP/LANL2DZ level in acetonitrile.

S12

0 4 8 12 16

Inte

nsity

(a.u

.)

Time / s

TBPyZnP ExpDec2

Model ExpDec2Equation y = A1*exp(-x/t1) + A2*exp(-x/t2) + y0

Reduced Chi-Sqr

2.05346E-9

Adj. R-Square 0.98732Value Standard Error

?$OP:F=1 y0 1.18308E-4 2.5039E-6?$OP:F=1 A1 0.00102 2.39889E-6?$OP:F=1 t1 6650.49575 54.66775?$OP:F=1 A2 0.00779 5.76782E-5?$OP:F=1 t2 242.82323 1.27283

Fig S5. Emission decay profile for TBPyZnP in degassed MeCN monitored at 610 nm.

500 600 700Emiss

ion

Inte

nsity

Nor

mal

ized

at 5

95 n

m

Wavelength / nm

ex250 ex300 ex350 ex400 ex420

Fig S6. Emission spectra of MBPyZnP-Ir normalized at 595 nm at different excitation

wavelength in MeCN at room temperature.

S13

500 600 700Emiss

ion

Inte

nsity

Nor

mal

ized

at 5

95 n

m

Wavelength / nm

ex250 ex300 ex350 ex400 ex420 ex440

Fig S7. Emission spectra of TBPyZnP-Ir normalized at 595 nm at different excitation

wavelength in MeCN at room temperature.

420 520 620 7200.00

0.22

0.44

0.66

0.88

1.10

0.00

0.22

0.44

0.66

0.88

1.10

Norm

alize

d Em

issio

n In

tens

ity Ir-complex TBPyZnP

Norm

alize

d Ab

sorb

ance

Wavelength (nm)

Fig S8. Spectral overlap of the normalized fluorescence spectrum of Ir-complex excited at

430-455 nm with the normalized absorption spectrum of TBPyZnP.

S14

-2.2 -1.7 -1.2 -0.7 -0.2 0.3 0.8 1.3 1.8

Potential vs Ferrocene (V)

Curr

ent (A

)

MBPyZnP TBPyZnP MBPyZnP-Ir TBPyZnP-Ir

Ferrocene

2.0 A

Fig S9. Cyclic voltammograms of the porphyrins recorded in MeCN (100 μM) at room

temperature.

550 600 650 700 750

0

100

200

300

400

500

600

MBPyZnP-Ir MBPyZnP-Ir + CoPyCl (0.003 M) MBPyZnP-Ir + CoPyCl (0.006 M) MBPyZnP-Ir + CoPyCl (0.009 M)

Wavelength (nm)

Emis

sion

Inte

nsity

(a)

0.000 0.002 0.004 0.006 0.008 0.010

1.0

1.5

2.0

2.5

3.0

3.5

I o/I

Concentration of CoPyCl (M)

Kq = 1.6 x 102 M-1

(b)

580 630 680 730

0

100

200

300

400

MBPyZnP-Ir MBPyZnP-Ir + TEA (0.07 M) MBPyZnP-Ir + TEA (0.14 M) MBPyZnP-Ir + TEA (0.21 M)

Emis

sion

Inte

nsity

Wavelength (nm)

(c)

0.00 0.05 0.10 0.15 0.20 0.250.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2.0

Concentraion of TEA (M)

I o/I

Kq = 4.58 M-1(d)

S15

Fig S10. Phosphorescence quenching of MBPyZnP-Ir (10 μM) with (a) CoPyCl and (c)

TEA as quencher in MeCN; Stern-Volmer plot of MBPyZnP-Ir with (b) CoPyCl and (d)

TEA as quencher.

50 100 150 200 250 300 350 4000

-10

-20

-30

-40

Light off

Curr

ent I

nten

sity

(mA/

cm2 )

Time (s)

MBPyZnP TBPyZnP MBPyZnP-Ir TBPyZnP-IrLight on

Fig S11. Photocurrent response of the porphyrins.

0

1

2

3

4

5

6

0.04

H 2 Pro

duct

ion

rate

(mm

ol g

-1 h

-1)

0.10

2.10

5.15

MBPyZnP

TBPyZ

nP

MBPyZnP

-Ir

TBPyZ

nP-Ir

Fig S12. H2 production rate of PSs (Photosensitizer (0.1 mM) + TEA (0.8 M) + CoPyCl (0.4

mM) + MeCN/H2O (1:2 v/v)) under irradiation for 5 h.

S16

0

2

4

6

8

10

12

14

16

18

20

12.60

14.42

8.23

0.80

M TE

A

H 2 P

rodu

ctio

n ra

te (m

mol

g-1 h

-1)

0.08 M

TEA

0.24 M

TEA

0.48

M TE

A

16.12

Fig S13. H2 production rate of PSs (TBPyZnP-Ir (0.1 mM) + TEA (0.08–0.8 M) + CoPyCl

(0.4 mM) + MeCN/H2O (2:1 = v/v)) under irradiation for 5 h.

0

1

2

3

4

5

6

7

8

H 2 Pro

duct

ion

rate

(mm

ol g

-1 h

-1)

TBPyZ

nP-Ir

MBPyZnP

-Ir

6.23

2.50

Fig S14. H2 production rate of PSs (Photosensitizer (0.1 mM) + TEA (0.8 M) + CoPyCl (0.2

mM) + MeCN/H2O (2:1 = v/v)) under irradiation for 5 h.

S17

0

2

4

6

8

10

12

14

16

18

10.0 M

0.01 0.02 0.20

2.93

16.12

H 2 Pro

duct

ion

rate

(mm

ol g

-1 h

-1)

0.5 M

1.0 M

100.0M

5.0 M

Fig S15. H2 production rate of PSs (TBPyZnP-Ir (0.5 -100 μM) + TEA (0.8 M) + CoPyCl

(0.4 mM) + MeCN/H2O (2:1 = v/v)) under irradiation for 5 h.

Fig S16. 1H NMR spectrum of MBPyP recorded in CDCl3.

N

NH N

HNN

N

*

S18

Fig S17. 13C NMR spectrum of MBPyP recorded in CDCl3.

Fig S18. 1H NMR spectrum of MBPyPH2-Ir recorded in acetone-D6. 13C NMR spectrum

could not be obtained for MBPyP-Ir.

N

NH N

HNN

N

N

NH N

HNN

N

Ir

NCF3

N

CF3

*

*

S19

Fig S19. 1H NMR spectrum of MBPyZnP-Ir recorded in acetone-D6. 13C NMR spectrum

could not be obtained for MBPyZnP-Ir.

Fig S20. 1H NMR spectrum of TBPyP recorded in CDCl3.

N

N N

NN

N

Ir

NCF3

N

CF3

Zn

N

NH N

HNN

N

N

N

N

N

N

N*

*

S20

Fig S21. 13C NMR spectrum of TBPyP recorded in CDCl3.

Fig S22. 1H NMR spectrum of TBPyPH2-Ir recorded in acetone-D6. 13C NMR spectrum

could not be obtained for TBPyPH2-Ir.

N

NH N

HNN

N

N

N

N

N

N

N

N

NH N

HNN

N

N

N

N

N

N

N

Ir

NCF3

N

CF3

Ir

NCF3

Ir

NF3C

N

CF3

IrN

CF3

NF3C

N

CF3

**

S21

N

N N

NN

N

N

N

N

N

N

N

Ir

NCF3

N

CF3

Ir

NCF3

Ir

NF3C

N

CF3

IrN

CF3

NF3C

Zn

N

CF3

Fig S23. 1H NMR spectrum of TBPyZnP-Ir recorded in acetone-D6. 13C NMR spectrum

could not be obtained for TBPyZnP-Ir.

Fig S24. MALDI-TOF MS spectrum of MBPyP.

N

NH N

HNN

N

*

*

*

S22

Fig S25. MALDI-TOF MS spectrum of TBPyP.

N

NH N

HNN

N

N

N

N

N

N

N

S23

Fig S26. MALDI-TOF MS spectrum of MBPyPH2-Ir.

N

NH N

HNN

N

Ir

NCF3

N

CF3

S24

Fig S27. MALDI-TOF MS spectrum of TBPyPH2-Ir.

N

NH N

HNN

N

N

N

N

N

N

N

Ir

NCF3

N

CF3

Ir

NCF3

Ir

NF3C

N

CF3

IrN

CF3

NF3C

N

CF3

S25

Fig S28. MALDI-TOF MS spectrum of MBPyZnP.

N

N N

NN

N

Zn

S26

Fig S29. MALDI-TOF MS spectrum of TBPyZnP.

N

N N

NN

N

N

N

N

N

N

N

Zn

S27

Fig S30. MALDI-TOF MS spectrum of MBPyZnP-Ir.

N

N N

NN

N

Ir

NCF3

N

CF3

Zn

S28

Fig S31. MALDI-TOF MS spectrum of TBPyZnP-Ir.

References:

(1) J. N. Demas and G. A. Crosby, J. Phys. Chem., 1971, 75, 991-1024.

(2) K. Nakamaru, Bull. Chem. Soc. Jpn., 1982, 55, 1639-1640.

(3) K. Araki, P. Losco, F. M. Engelmann, H. Winnischofer and H. E. Toma, J. Photochem.

Photobiol. A, 2001, 142, 25-30.

(4) D. Wang, H.-G. Chen, X.-C. Tian, X.-X. Liang, F.-Z. Chen and F. Gao, RSC Adv., 2015,

5, 107119-107122.

(5) S. Chen, G. Tan, W.-Y. Wong and H.-S. Kwok, Adv. Funct. Mater., 2011, 21, 3785-3793.

N

N N

NN

N

N

N

N

N

N

N

Ir

NCF3

N

CF3

IrN

CF3N

CF3

Ir

NF3C

N

CF3

IrN

CF3

NF3C

Zn