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