Marcel Enke, Stefan Bode, Jürgen Vitz, Felix H. Schacher, Matthew J. Harrigton, Martin D.
Hager,* Ulrich S. Schubert*
- S1 -

Figures: a)
8
2 - 5
11
8
9
7
1
10'
10
6
6 5
7
4
 [ppm] 
3 2 1 0 b)
1.0
[M+H]
+
0.5
[Trt+H]
+
[M+Na]
+
0.0
200 250 300 350 400 m/z
450 500 550 600
Figure S1: a) 1 H NMR spectrum of N
α
-methacryloylN
τ
-tritylhistidine methyl ester ( 3 )
(300 MHz, CDCl
3
) and b) ESI-spectrum of 3 .
- S2 -

a) b)
3 - 5
10
2
1
9'
9
6 7
8
11 10 9 8 7 6 5
 [ppm] 
4 3 2 1 0
1.0
[Trt+H]
+
[M+H]
+
0.5
[M+Na]
+
0.0
200 250 300 350 400 450 500 m/z
Figure S2: a)
1
H NMR spectrum of N
α
-methacryloylN
τ
-tritylhistidine ( 4 ) (300 MHz, CDCl
3
) and b) ESI-spectrum of 4 .
- S3 -

a)
CDCl
3 backbone
8
8
3
7 2
3
1
7 6
5
5 4
 [ppm] 
6
4
3 2 1 0 b)
CDCl
3 backbone
7
2, 8 1
4
5
3
8 7 6 5 4
 [ppm] 
3 2 1 0
Figure S3: a)
1
H NMR spectrum of P1 (300 MHz, CDCl
3
) and b)
1
H NMR spectrum of P5
(300 MHz, CDCl
3
).
- S4 -

1.0
0.5
P1
P5
0.0
14 15 16 17 18
Elution volumen [mL]
19
Figure S4: SEC curves of polymer P1 and P5 ( DMAc + 0.21% LiCl ).
20
- S5 -

a)
1.00
0.75
0.50
0.25
0.00
-100
T g
0
Temperature [°C]
100 200 b)
100
75
50
25
0
0 200 400
Temperature [°C]
600 800
Figure S5: a) DSC curve of P1 (2 nd heating run); the glass transition temperature ( T g
) could be assigned to 45 °C, b) TGA curve of
P1 .
- S6 -

1.00
0.75
0.50
0.25
0.00
-100 0
Temperature [°C]
100 200
Figure S6: DSC curve of P2 (2 nd heating run), no glass transition temperature ( T g
) could be obtained. The endothermic peak at approximately ‒35 °C indicates a side-chain crystallization of the PLMA chains.
- S7 -

0,05 0,10 0,15 q [nm
-1
]
Figure S7: SAXS measurement of MP4 .
0,20 0,25
- S8 -

a)
2.0
1.5
1.0
0.5
3.0
2.5
0.0
0 100 200 300 400 500 600 700
Indentation depth (nm)
800 900 1000
MP4 a
MP4 b
MP4 c
MP4 d
MP5 a
MP5 b
MP5 c
MP5 d
MP6 a
MP6 b
MP6 c
MP6 d
0.10
0.08
0.06
0.04
0 100 200 300 400 500 600 700
Indentation depth (nm)
800 900 1000
- S9 -
MP4 a
MP4 b
MP4 c
MP4 d
MP5 a
MP5 b
MP5 c
MP5 d
MP6 a
MP6 b
MP6 c
MP6 d

b) c)
4000
3500
3000
2500
2000
1500
1000
500
0
0 100 200 300 400 500 600 700 800 900 1000 1100 1200
Depth (nm)
4000
3500
3000
2500
2000
1500
1000
500
0
0 100 200 300 400 500 600 700 800 900 1000 1100 1200
Depth (nm)
- S10 -

d)
4000
3500
3000
2500
2000
1500
1000
500
0
0 100 200 300 400 500 600 700 800 900 1000 1100 1200
Depth (nm) e) softer
4000
3500
3000
2500
2000
1500
1000
500
MP4
MP5
MP6
0
0 200 400 600
Depth (nm)
800 1000 1200
Figure S8: Mechanical properties measured by nanoindentation of MP4 to MP6 . a) Loaddisplacement data and indentation modulus of MP4 (b), MP5 (c) and MP6 (d). e) Overlay of load-displacement data for maximum load for MP4 , MP5 and MP6 .
- S11 -

Figure S9: Self-healing experiments of MP1 to MP3 . (a) Film without scratch ( MP1 ), (b) scratch, (c) incomplete healing after 100 h at 120 °C, (d) film without scratch ( MP2 ), (e) scratch, (f) healing after 19 h at 120 °C, (g) film without scratch (
MP3 ), (h) scratch and (j) healing after 38 h at 70 h.
- S12 -

Figure S10: Brittle films of MP7 (a), MP8 (b) and MP9 (c).
- S13 -

Figure S11: Self-healing experiments of MP10 . (a) Film without scratch, (b) first scratch, (c) incomplete healing after 40 h at 100 °C, (d) first healing after 80 h at 100 °C, (e) second scratch, (f) second healing after 19 h at 100 °C, (g) third scratch, (h) incomplete healing after
40 h at 90 °C and (j) incomplete healing after 200 h.
- S14 -

Figure S12: Self-healing experiments of MP11 and MP12 . (a) Film without scratch ( MP11 ),
(b) scratch, (c) healing after 20 h at 100 °C, (d) film without scratch ( MP12 ), (e) scratch and
(f) healing after 60 h at 90 °C.
- S15 -

Figure S13: Self-healing experiments of MP13 to MP15 . (a) Film without scratch ( MP13 ),
(b) scratch, (c) healing after 20 h at 100 °C, (d) film without scratch (
MP14 ), (e) scratch, (f) healing after 40 h at 150 °C, (g) film without scratch (
MP15 ), (h) scratch and (j) healing after
20 h at 100 °C.
- S16 -

Figure S14: Self-healing experiments of MP22 to MP24 at room temperature ( MP22 and
MP23 heal at 50 °C completely). (a) Film without scratch ( MP22 ), (b) scratch, (c) incomplete healing after 100 h, (d) film without scratch ( MP23 ), (e) scratch, (f) incomplete healing after
100 h, (g) film without scratch ( MP24 ), (h) scratch and (j) healing after 100 h.
- S17 -

Tables:
Table S1: Overview of the elemental analysis results and terminal properties of metallopolymers MP1 to MP24 .
Metallopolymer
MP1
MP2
MP3
MP4
MP5
MP6
MP7
MP8
MP9
MP10
MP11
MP12
MP13
MP14
MP15
MP16
MP17
MP18
MP19
MP20
MP21
MP22
MP23
MP24
Carbon
[%]
66.29
63.53
74.99
74.97
73.19
63.22
63.27
60.11
66.63
66.89
66.33
74.55
74.91
74.42
66.53
72.65
74.36
70.62
64.76
65.51
64.26
73.33
73.66
73.20
Hydrogen
[%]
9.03
8.67
11.37
11.01
10.74
9.25
9.27
8.90
8.77
8.75
8.77
11.67
11.66
11.14
9.04
11.61
11.61
11.24
9.41
9.60
9.40
11.51
11.58
11.16
Nitrogen
[%]
0.58
0.55
1.03
1.63
1.64
2.00
1.14
1.15
1.32
1.65
1.70
1.12
1.14
1.40
2.21
2.24
2.77
2.26
2.34
2.52
0.59
0.61
0.69
1.64
Chloride
[%]
0.95
‒
‒
1.71
‒
‒
1.60
‒
‒
0.52
‒
‒
3.12
‒
‒
0.44
‒
‒
0.72
‒
‒
0.25
‒
‒
82
42
88
‒
‒
‒
46
40
42
‒70
‒59
‒67
DSC:
T g
[°C]
51
53
47
‒
‒63
‒
54
48
47
‒48
‒54
‒40
213
190
222
215
191
221
239
208
238
302
275
306
315
255
296
297
240
TGA:
T d
[°C]
329
322
295
288
237
280
300
- S18 -

Table S2: Depth-sensing indentation (DSI) results of MP4 to MP6 .
Sample M.-points a
Reduced modulus E r b, c
Average a Standard deviation Average a
Hardness b, c
Standard deviation
Indentation modulus E i d
Average a Standard deviation
MP4
N
58 f
GPa
1.774
GPa
0.042
GPa
0.055
GPa
0.005
GPa
1.493
GPa
0.036
MP5 58 f 1.874 0.056 0.057 0.005 1.577 0.047
MP6 58 f 2.049 0.160 0.057 0.005 1.724 0.135 a Measurements were repeated at sixteen maximum loads in a 4 × 4 array, increasing in steps of 140 µN from 100 µN to 2200 µN and 2000 µN to 4100 µN. b The depth-sensing indentation (DSI) was conducted at ambient conditions at 23.8±0.1 °C and 18.0±2.5% relative humidity (RH). Values are averaged, measurements outside the area function limits were excluded. c For quasi-static testing, a 1 s loading, 2 s hold at maximum load, and 1 s unloading profile was applied. d From the reduced modulus E r
, the indentation modulus E i
was calculated using the analysis method proposed by Oliver and Pharr, using the elastic modulus and
Poisson’s ratio of the diamond indenter, 1140 GPa and 0.07, respectively, and a Poisson’s ratio of 0.4 for the polymeric material.
[S1] f
four measuring areas.
- S19 -

Experimental Section:
N
τ
-Tritylhistidine methyl ester (1)
L-Histidine methyl ester dihydrochloride (6.77 g, 40.00 mmol) was suspended in 20 mL dry chloroform and cooled to 0 °C under nitrogen atmosphere. Subsequently, triphenylmethyl chloride (15.86 g, 56.90 mmol) and triethylamine (15.86 mL,
113.80 mmol) dissolved in 85 mL dry chloroform was added dropwise. The resulting mixture was stirred overnight. Subsequently, the organic layer was washed three times with 50 mL water, dried over Na
2
SO
4
and evaporated in vacuo .
Afterwards, the residue was dissolved in 40 mL acetic acid. Subsequently, the same volume of 1N HCl was added. The resulting suspension was stirred for 1 h at room temperature and filtered off. The filtrate was washed three times with 50 mL diethyl ether. Afterwards, the aqueous layer was treated with solid K
2
CO
3
until a pH value of 9 was achieved. The aqueous layer was extracted with chloroform. The combined organic layer was washed with an aqueous saturated solution of K
2
CO
3
and dried over Na
2
SO
4
. Evaporation of the solvent gave the product.
Yield: 6.5 g of a yellow solid, 62% (Lit.: 63%) [S2]
Melting point: 121 °C
1 H NMR (300 MHz, CDCl
3
): δ = 1.79 (bs, 2H, -N H
2
), 2.92 (dq, J = 7.0 Hz, 20.0 Hz, 2H, -
C H
2
), 3.64 (s, 3H, -C H
3
), 3.80 (m, 1H, -C H -), 6.58 (s, 1H, H -
2 Im), 7.09 ‒ 7.15 (m, 6H,
H aromatic), 7.29 ‒ 7.34 (m, 9H, H -aromatic), 7.36 (s, 1H, H 5 Im) ppm.
13 C NMR (75 MHz, CDCl
3
):
δ
= 33.7 (C H
2
-), 51.99 (-O C H
3
), 54.8 (C H-), 75.3 (C -Ph
3
),
119.6 ( C -
2
Im), 128.2 ( C -
4
Ph; C -
2
Ph; C -
6
Ph), 129.9 ( C -
3
Ph; C -
5
Ph), 137.4 ( C -
3
Im), 138.9 ( C-
5
Im), 142.6 ( C -
1
Ph), 175.7 ( C =O) ppm.
ESI-TOF MS (HR MS): calc.: m/z = 412.2020 [M+H]
+
; found: m/z = 412.2003 [M+H]
+
; error: 3.9 ppm.
- S20 -

N
τ
-Tritylhistidine (2)
A solution of L-histidine (15.5 g, 100 mmol) in 150 mL dry dichloromethane was heated under reflux with dichlorodimethylsilane (12.1 mL, 100 mmol) under nitrogen atmosphere.
After 4 h, triethylamine (27.9 mL, 200 mmol) was added and the mixture was further refluxed for 15 min. Subsequently, triethylamine (13.9 mL, 100 mmol) and triphenylmethyl chloride (27.9 g, 100 mmol) dissolved in 100 mL dry dichloromethane were slowly added. After 2 h, 25 mL methanol were added and the solution was concentrated. The pH value was adjusted to 8.5 by the addition of 10 mL deionized water and dropwise addition of triethylamine. Subsequently, the residue was treated with 75 mL chloroform and the product was filtered off, which was washed three times with 50 mL deionized water and dried in vacuo at 100 °C for 2 days.
Yield: 21 g of a white solid, 53% (Lit.: 97%)
[S3]
Melting point: 219 to 220 °C (Lit.: 218 to 220 °C)
[S3]
1 H NMR (400 MHz, d
8
-THF/D
2
O 1:1):
δ = 2.85 ‒ 3.12 (m, 2H, -C
H
2
-), 3.85 (dd, J = 4.5 Hz,
4.0 Hz, 1H, -C H -), 6.78 (s, 1H, H -
2 Im), 7.06 ‒ 7.09 (m, 6H,
H -aromatic), 7.28 ‒ 7.30 (m, 9H,
H -aromatic), 7.35 (s, 1H, H 5 Im) ppm.
13 C NMR (100 MHz, d
8
-THF/D
2
O 1:1): δ = 29.4 (C H
2
-), 55.9 (C H-), 76.3 (C -Ph
3
), 120.9
( C 2 Im), 128.8 ( C 4 Ph), 128.9 ( C 2 Ph; C 6 Ph), 130.3 ( C 3 Ph; C 5 Ph), 136.7 ( C 3 Im), 139.5 ( C -
5 Im), 143.1 ( C 1 Ph), 173.3 ( C =O) ppm.
ESI-TOF MS (HR MS): calc.: m/z = 420.1682 [M+H]
+
; found: m/z = 420.1672 [M+H]
+
; error: 2.5 ppm.
Overview of the calculations for Table 3:
For the synthesis of the crosslinked metallopolymers, the number molar average mass was calculated based on the
1
H NMR data of the copolymers (repeating units containing one histidine moiety). Afterwards, this mass was utilized to calculate the required amount of zinc salt to obtain the ratio 1:3 Zn/His.
Example on P1 : ratio of His/BMA based on
1
H NMR: 1:9.1, which leads to a repeating unit of
C
118
H
183
O
25
N
3
with a molar mass of 2043.78 g/mol. The required amount of metal salt
(Summarized in Table 3) can be calculated with the following equation:
- S21 -

m
Salt
3 m
Polymer
M
Polymer

M
Salt
In the case of MP1 Zn(II) chloride as salt was used: m
Salt
1
3
48.3 mg g
2043.78 mol

136.30 g mol

1.07 mg

1.1 mg
References:
[S1] W. C. Oliver, G. M. Pharr, J. Mater. Res.
1992 , 7 , 1564–1583.
[S2] R. A. Himes, G. Y. Park, G. S. Siluvai, N. J. Blackburn, K. D. Karlin, Angew. Chem.
Int. Ed. 2008 , 47 , 9084-9087.
[S3] K. Barlos, D. Papaioannou, D. Theodoropoulos, J. Org. Chem. 1982 , 47 , 1324-1326.
- S22 -