Nature - USA (2019-07-18)

Letter reSeArCH

–400

–200

0

200

400

020406080100

–70

0

70

140

210

04812 16

Distance (nm) Distance (nm)

Height (pm) Height (pm)

5 nm

ac

40 nm 40 nm 100 nm

0.3 nm

e

bd

f

Fig. 2 | STM and AFM images of fjord-type GNR 2. a, STM image of
fjord-type GNR 2 (Mn = 1.5 ×  105  Da, Đ = 1.22) deposited on HOPG
(voltage U = 1.0 V, current I =  50  pA, temperature T =  78  K).
b, Cross-sectional height profile taken along the white line in
a, perpendicularly to the observed stripes. c, AFM height image of GNR 2

(Mn = 1.5 ×  105  Da, Đ = 1.22) on HOPG. d, Cross-sectional height profile

taken along the white line in c, perpendicularly to the observed stripes.

e, AFM phase image of c. f, Height image of submicrometre-scale self-

assembly of GNR 2 (Mn = 1.5 ×  105  Da, Đ = 1.22).

10 12 14 16 18 20

Normalized intensity

Retention time (min)

Retention time (min)

12 14 16 18 20 22 24

Intensity

Pd(OCOCF 3 ) 2

AgSbF 6

o-chloranil

ClCH 2 CH 2 Cl

80 °C, 21.5 h

n-octyl

Et Et

Si

R

+

R RRn–1

K region

Initiator R =

I′

Monomer

M

Initial

intermediate

6

Fjord-type GNR

7

After 6 h

After 12 h

Fjord-type GNR

2

Mn = 31 kDa

Ð = 1.21

Monomer

M′′

5 2

Block fjord-type GNR

5

Mn = 68 Da

Ð = 1.23

Initiator

I Block fjord-type GNR

5

Mn = 30 Da

Ð = 1.22

Mn = 67 kDa

Ð = 1.24

50 : 1

100 : 1

300 : 1

500 : 1

12

30

96

150

1.04

1.04

1.03

1.04

34

80

254

391

76%

83%

70%

72%

14

35

108

169

a b

c d

e f

n–1 n–1 m–1

RR

Pd(OCOCF 3 ) 2

AgSbF 6

o-chloranil

ClCH 2 CH 2 Cl

80 °C, 12 h

n-octyl

Et Et

Si

TEG

+

R = RRTEG TEG

TEG = O O

3

Pd(OCOCF 3 ) 2 (100 equiv.)

AgSbF 6 (200 equiv.)

o-chloranil (200 equiv.)

M (100 equiv.)

ClCH 2 CH 2 Cl

80 °C, 6 h

M′′ (100 equiv.)

80 °C

6 h

n–1

RRTEG TEG

m–1

M/I′

Mna

(kDa) Ða DPa,b

Yield

of 7 d

Length

(nm)c

Fig. 3 | Living APEX block copolymerization and highly controlled
living APEX polymerization. a, Living APEX block copolymerization
using GNR 2 as the initiator and benzonaphthosilole M′′ as the monomer.
Reaction conditions: 2 (1.0 equiv.), M′′ (100 equiv.), Pd(OCOCF 3 ) 2 (100
equiv.), AgSbF 6 (200 equiv.), o-chloranil (200 equiv.), ClCH 2 CH 2 Cl,
80 °C, 12  h. b, SEC charts before and after the reactions. c, Confirmation
of livingness of APEX polymerization of I, M and M′′ by one-pot SEC
analyses. d, SEC charts of the reaction progress after 6 and 12  h. e, Living

APEX polymerization using diphenylacetylene (I′) as the initiator and M

as the monomer. Reaction conditions: M (1.0 equiv.), Pd(OCOCF 3 ) 2 (1.0

equiv.), AgSbF 6 (2.0 equiv.), o-chloranil (2.0 equiv.), ClCH 2 CH 2 Cl, 80 °C,

21.5 h. f, Results of polymerization with various molar ratios of M/I′.

aDetermined using PS standards. bCalculated using M

n.

cEstimated length

using DP. All analyses of Mn and Đ were conducted with the crude product

of GNRs. dIsolated yield after purification by SEC.

18 JULY 2019 | VOL 571 | NAtUre | 389