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Supplementary Information
Supplementary Figure S1. Scheme of synthesis of various monomers.
2
Supplementary Figure S2. Scheme of synthesis of block copolymers.
3
Supplementary Figure S3. Plot of Mn vs. monomer to initiator ratio for a series of five different
polymerizations. The linear trend demonstrates these polymerizations are living within the
molecular weight ranges studied.
4
Supplementary Figure S4. AFM images of thin spun cast films. AFM was used to qualitatively
understand the phase separation as a function of the alkyl side chain length. As the side chain is
made longer, the phase separation improves. The C5 shows little contrast and is therefore not
shown.
5
Supplementary Figure S5. SAXS curve for the block copolymer before annealing. The two
peaks correspond to 1 and 3 , consistent with a cylindrical morphology. The SAXS pattern
does not change after thermal treatment.
6
Supplementary Figure S6. TGA of the C16 homopolymer and the diblock copolymer. The C16
homopolymer demonstrates the basic polymer is stable to above 350°C while the Cobalt
containing block copolymer has a thermal transition starting around 100°C. Using weight loss to
calculate carbonyl loss, it is determined that 94% of the carbonyl ligands have been evaporated.
7
Supplementary Figure S7. TGA of the cobalt-containing homopolymer. Similar to the block
copolymer, the carbonyl ligands are evaporated starting around 100°C and then backbone
degradation begins around 350°C. This sample contains 26 wt% of cobalt which is consistent
with the weight loss present at 200°C.
8
Supplementary Figure S8. Microtomed TEM image of the block copolymer before thermal
treatment. This is an unstained TEM image since the Cobalt containing minor phase provides
plenty of contrast. This end-on cylinder view is consistent with the SAXS curve collected for the
same sample.
9
Supplementary Figure S9. (left) Homopolymer before thermal treatment shows no contrast as
expected for a homogenous sample. (right) Homopolymer after thermal treatment shows small
black structures consistent with cobalt nanoparticle formation.
10
DSCN1080-1.wmv
Supplementary Movie S1. Movie demonstrating the response of thermally annealed both the
paramagnetic homopolymer and the room temperature ferromagnetic block copolymer to an
external magnet.
11
Supplementary Figure S10. Moment vs. Temperature for the thermally treated homopolymer
using both zero field cooling and field cooling at 100 Oe showing that the material is
paramagnetic. Because the material is paramagnetic, the data points overlap. The sample was not
demagnetized and used as it is for the experiments.
12
Supplementary Figure S11. Moment vs. Temperature for the thermally treated block
copolymer using both zero field cooling and field cooling at 100 Oe. The observed difference in
ZFC and FC is typical for ferromagnetic materials. The sample was not demagnetized and used
as it is for the experiments.
13
Supplementary Figure S12. The chemical state of cobalt was investigated by Near edge X-ray
absorption fine structure (NEXAFS) spectroscopy of the BCP and homopolymer before and after
heat treatment. The peak position of Co LIII edge is shifted to lower energy indicating the
decarbonylation of dicobalt hexacarbonyl after heat treatment in both homopolymer and block
copolymer. Further, the shape of the peaks (i.e. no splitting) after heat treatment is also
consistent with the cobalt foil (Coº species) reported in the literature. In NEXAFS of nanosized
cobalt particles, the Co LIII peak was shifted higher by 1.5eV than bulk cobalt foil.43
14
Supplementary Figure S13. TGA of the diblock copolymer containing the cobalt and ferrocene
monomers in the ratio x : y = 0.3 : 0.7. Similar to the cobalt containing block copolymer, the
carbonyl ligands are evaporated starting around 100°C and then backbone degradation begins
around 350°C. The weight loss at 200°C is 5%, which is in agreement with the theoretically
calculated amount of carbonyl ligands in the polymer. As the mol% of the cobalt containing
monomers changes (increases or decreases), the carbonyl loss changed accordingly.
15
Supplementary Figure S14: TGA of the ferrocene-containing homopolymer. The polymer is
completely inert at 200°C, the temperature used to evaporate the carbonyl ligands. Backbone
degradation begins around 350°C.
16
Supplementary Figure S15: To investigate whether the observed room temperature
ferromagnetic behavior was solely confined to the one block copolymer reported in the
manuscript, we prepared another block copolymer/homopolymer combination shown here and
below in Figure SI10b. We used ferrocene to ‘dilute’ the cobalt metal-containing block and to
ensure phase separation. This block copolymer self-assembles into a cylindrical phase and after
a thermal treatment at 200°C (ferrocene is completely stable) the resultant material is indeed a
room temperature ferromagnet as shown by the SQUID magnetometer data.
17
Supplementary Table
Supplementary Table S1. Characterization of Monocobalt-containing Block Copolymers
polymer Mn,GPC (kDa) Mw,GPC (kDa) n/ma fCob PDI
M1 82 91 137/59 0.32 1.11
M2 76 85 106/71 0.39 1.12
M3 73 82 83/83 0.50 1.12
M4 80 88 71/107 0.56 1.10
M5 74 83 48/112 0.65 1.12 a First, the molar ratios of two monomers were obtained from 1H NMR integration, and then
degree of polymerizations (DPs) were calculated using the Mn data from THF GPC. b Volume
fractions of Co-containing block were calculated based on density data obtained by density
column method.
18
Supplementary Methods
Experimental Section
General. Unless otherwise noted, all reagents were purchased either from Acros Organics,
Aldrich, or Strem and used without further purification. CH2Cl2 and THF were distilled over
CaH2 and Na0/benzophenone prior to use, respectively. Third generation Grubbs’ catalyst and
exo-oxanorbornene were synthesized according to the literature. The 1H NMR spectra were
recorded on a Bruker DPX-300 MHz spectrometer. Chemical shifts are expressed in δ (ppm)
using residual solvent protons or TMS as internal standard. Molecular weights and PDIs were
measured by GPC equipped with two-column sets (Polymer Laboratories) and RI detectors
(HP1047A) using THF as mobile phase with a flow rate of 1 mL/min, relative to polystyrene
standards.
General Synthesis Procedure for Compounds 2a, 3a and 5a. Compound 1a, alcohol
derivatives, and 1.1 equiv of triphenylphosphine, THF were added to a round-bottom flask. After
immersing the flask in an ice bath, 1.1 equiv of diisopropylazodicarboxylate (DIAD) was added
dropwise. The ice bath was then removed, and the reaction was allowed to stir at room
temperature for 24 h. The solvent was removed under reduced pressure by rotavap. The product
was purified by recrystallization or column chromatography.
Synthesis of Compound 2a. Compound 1a (4.44 g, 26.9 mmol), 1-hexadecanol (5.93 g, 24.5
mmol), triphenylphosphine (7.06 g, 26.9 mmol), diisopropylazodicarboxylate (DIAD) (5.33 ml,
26.9 mmol). The product was isolated and purified by recrystallization from methanol. The pure
product is a white solid. Yield: 8.57 g (22.0 mmol, 90%). 1H NMR (300 MHz, CDCl3): δ 6.50 (s,
19
2H), 5.26 (s, 2H), 3.45 (t, 2H), 2.82 (s, 2H), 1.56-1.38 (m, 2H), 1.28-1.10 (m, 26H), 0.88 (t, 3H).
13C NMR (75 MHz, CDCl3): δ 176.32, 136.55, 80.90, 47.38, 39.05, 31.94, 29.70, 29.68, 29.64,
29.56, 29.48, 29.38, 29.14, 27.62, 26.70, 22.71, 14.16. FAB-MS (m/z): [M]+ calculated
forC24H39NO3, 389.6; found, 389.3.
Synthesis of Compound 3a. Compound 1a (4.03 g, 24.4 mmol), progargyl alcohol (1.57 ml,
26.8 mmol), triphenylphosphine (7.04 g, 26.8 mmol), diisopropylazodicarboxylate (DIAD) (5.32
ml, 26.8 mmol). The product was isolated by recrystallization from diethyl ether, and then
purified by chromatography (SiO2, ethyl acetate/hexane = 3/2). The pure product is a white solid.
Yield: 4.45 g (21.9 mmol, 90%). 1H NMR (300 MHz, CDCl3): δ 6.50 (s, 2H), 5.25 (s, 2H), 4.20
(s, 2H), 2.91 (s, 2H), 2.17 (s, 1H). 13C NMR (75 MHz, DMSO-d6): δ 175.80, 137.00, 80.79,
78.14, 74.15, 47.71, 27.68. FAB-MS (m/z): [M]+ calculated for C11H9NO3, 203.2; found, 203.1.
Synthesis of Compound 4a. Compound 3a (2.04 g, 10.0 mmol) was dissolved in 50 ml CH2Cl2
in a round-bottom flask, and Co2(CO)8 (6.87 g, 20.0 mmol) was added when the flask was
immersed in an ice bath. The reaction mixture was allowed to stir in the ice bath for 2 h and at
room temperature for another 2 h. After reaction, the solvent was removed under nitrogen flow.
Pentane (150ml) was then added to dissolve the excess of Co2(CO)8 and to precipitate the
product. The pure product was obtained by chromatography (SiO2, CH2Cl2/ acetone = 9/1), as a
red solid. Yield: 3.67 g (7.5 mmol, 75%). 1H NMR (300 MHz, CDCl3): δ 6.50 (s, 2H), 6.00 (s,
1H), 5.27 (s, 2H), 4.80 (s, 2H), 2.89 (s, 2H). 13C NMR (75 MHz, DMSO-d6): δ 199.50, 176.35,
137.01, 90.00, 80.78, 73.92, 47.57, 41.12. ESI-MS (m/z): [M]+ calculated for C17H9NO9Co2,
489.1; found, 488.9.
20
Synthesis of Compound 5a. Compound 1a (2.0 g, 12.2 mmol), ferrocene methanol (2.88g, 13.4
mmol), triphenylphosphine (3.50 g, 13.4 mmol), diisopropylazodicarboxylate (DIAD) (2.7 ml,
13.4 mmol). The product was isolated by precipitation from diethyl ether, and then purified by
chromatography (SiO2, ethyl acetate/hexane = 2/3). The pure product is obtained by
recrystallization from methanol. The final product is a yellow solid. Yield: 1.62 g (4.46 mmol,
37%). 1H NMR (300 MHz, CDCl3): δ 6.47 (s, 2H), 5.23 (s, 2H), 4.39 (s, 2H), 4.26 (d, 2H), 4.15
(s, 5H), 4.08 (d, 2H), 2.76 (s, 2H). 13C NMR (75 MHz, CDCl3): δ 175.78, 136.60, 81.83, 80.89,
69.36, 68.75, 68.31, 47.52, 39.28. FAB-MS (m/z): [M]+ calculated forC19H17NFeO3, 363.2;
found, 363.1.
General Procedure for Block Copolymer Synthesis with Cobalt metal Block. Known
amounts of monomers 2a and 4a were added into two separate Schlenk flasks under an
atmosphere of nitrogen, and dissolved in anhydrous CH2Cl2 (1 ml per 100 mg of monomer). A
desired amount of third generation Grubbs’ catalyst was added into another Schlenk flask,
flushed with nitrogen, and dissolved in a minimum amount of anhydrous CH2Cl2. All three
solutions were degassed three times by freeze-pump-thaw cycles. First, monomer 2a was
transferred to the flask containing the catalyst via cannula. The reaction mixture was stirred
vigorously for 5 minutes, after which an aliquot was taken for GPC analysis, and monomer 4a
was transferred to the flask via a cannula. The polymerization was allowed to continue for
another 5 minutes, and then quenched with 0.2 ml of ethyl vinyl ether. An aliquot was taken for
GPC analysis, and the remaining product was precipitated from methanol.
21
General Procedure for Block Copolymer Synthesis with Cobalt and Ferrocene metal Block
(Dilution Studies): Known amounts of monomers 4a and 5a were mixed and added into a single
Schlenk flask under an atmosphere of nitrogen, and dissolved in anhydrous CH2Cl2 (1 ml per 100
mg of monomers). A desired amount of third generation Grubbs’ catalyst and Compound 2a
were added into separate Schlenk flasks, flushed with nitrogen, and dissolved in a minimum
amount of anhydrous CH2Cl2. All three solutions were degassed three times by freeze-pump-
thaw cycles. First, monomer 2a was transferred to the flask containing the catalyst via cannula.
The reaction mixture was stirred vigorously for 6 minutes, after which an aliquot was taken for
GPC analysis, and then the solution containing monomer 4a and 5a was transferred to the flask
via a cannula. The polymerization was allowed to continue for another 8 minutes, and then
quenched with 0.2 ml of ethyl vinyl ether. An aliquot was taken for GPC analysis, and the
remaining product was precipitated from methanol.
Block Copolymer M1. 1H NMR (300 MHz, CDCl3): δ 6.20-5.96 (br, 1H), 5.92-5.62 (br,
1.11H), 5.20-4.90 (br, 1.12H), 4.90-4.70 (br, 0.66H), 4.64-4.32 (br, 0.71H), 3.64-3.12 (m,
2.94H), 1.80-0.50 (m, 18.56H). 13C NMR (75 MHz, CDCl3): δ 199.9, 176.0, 132.5, 117.7, 53.5,
32.0, 29.7, 27.7, 26.8, 22.7, 14.1. GPC: Mn = 82 kDa, Mw/Mn = 1.11.
Block Copolymer M2. 1H NMR (300 MHz, CDCl3): δ 6.20-5.96 (br, 1H), 5.94-5.62 (br,
1.06H), 5.20-4.90 (br, 1.09H), 4.90-4.70 (br, 0.68H), 4.64-4.32 (br, 0.63H), 3.64-3.12 (m,
2.60H), 1.80-0.50 (m, 15.14H). 13C NMR (75 MHz, CDCl3): δ 199.9, 176.0, 132.5, 117.7, 53.5,
32.0, 29.7, 27.7, 26.8, 22.7, 14.1. GPC: Mn = 76 kDa, Mw/Mn = 1.12.
22
Block Copolymer M3. 1H NMR (300 MHz, CDCl3): δ 6.20-5.92 (br, 1H), 5.92-5.58 (br,
1.12H), 5.20-4.90 (br, 1.13H), 4.90-4.64 (br, 0.95H), 4.64-4.30 (br, 0.66H), 3.64-3.09 (m,
2.54H), 1.80-0.50 (m, 13.44H). 13C NMR (75 MHz, CDCl3): δ 199.9, 176.0, 132.5, 117.7, 53.5,
32.0, 29.7, 27.7, 26.8, 22.7, 14.1. GPC: Mn = 73 kDa, Mw/Mn = 1.12.
Block Copolymer M4. 1H NMR (300 MHz, CDCl3): δ 6.28-5.95 (br, 1H), 5.95-5.60 (br,
0.99H), 5.22-4.92 (br, 1.03H), 4.92-4.65 (br, 0.90H), 4.65-4.30 (br, 0.50H), 3.68-3.10 (m,
1.99H), 1.80-0.50 (m, 8.33H). 13C NMR (75 MHz, CDCl3): δ 199.9, 176.0, 132.5, 117.7, 53.5,
32.0, 29.7, 27.7, 26.8, 22.7, 14.1. GPC: Mn = 80 kDa, Mw/Mn = 1.10.
Block Copolymer M5. 1H NMR (300 MHz, CDCl3): δ 6.24-5.94 (br, 1H), 5.94-5.60 (br,
0.99H), 5.21-4.92 (br, 1.04H), 4.92-4.65 (br, 1.04H), 4.65-4.30 (br, 0.48H), 3.66-3.10 (m,
1.79H), 1.80-0.50 (m, 5.93H). 13C NMR (75 MHz, CDCl3): δ 199.9, 176.0, 132.5, 117.7, 53.5,
32.0, 29.7, 27.7, 26.8, 22.7, 14.1. GPC: Mn = 74 kDa, Mw/Mn = 1.12.
TEM Sample Preparation: Samples for TEM were prepared by drop-casting a 10 wt %
toluene solution into a teflon mold, the sample was then solvent annealed in benzene for two
weeks, embedded in an epoxy resin, and cured at 60°C for 24 hours. Ultra thin sections were
then cut with a diamond knife using a Leica Ultracut microtome. TEM analysis was conducted
on a JEOL 100CX TEM operating at an accelerating voltage of 100 kV. For samples studied
after annealing, the samples were heated to 200°C after solvent annealing but before epoxy
treatment.
23
SAXS Sample Preparation: Small angle x-ray scattering samples were prepared by drop-
casting a 10 wt % toluene solution into a teflon mold, the sample was then solvent annealed in
benzene for two weeks. The calculated center-to-center d-spacing of microdomains was found to
be 40 nm.
Magnetic Measurements: Based on the Ms value of 3.5 emu/g of block copolymer and the fact
that it contains ~14 wt% cobalt, the Ms is 25 emu/g of cobalt, or 1475 emu/mole of cobalt
compared to bulk cobalt which is 166 emu/g, or 9700 emu/mole of cobalt.44,45
Supplementary References
43 Papaefthimiou, V. et al. Nontrivial Redox Behavior of Nanosized Cobalt: New Insights
from Ambient Pressure X-ray Photoelectron and Absorption Spectroscopies. ACS Nano,
(2011).
44 Miller, J. S. & Epstein, A. J. Organic and Organometallic Molecular Magnetic Materials -
Designer Magnets. Angewandte Chemie International Edition In English 33, 385-415,
(1994).
45 Salavati-Niasari, M., Davar, F., Mazaheri, M. & Shaterian, M. Preparation of cobalt
nanoparticles from [bis(salicylidene)cobalt(II)]-oleylamine complex by thermal
decomposition. J Magn. Magn. Mat. 320, 575-578, (2008).