Supporting Information
Copyright Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, 2011
Platinum Nanoparticles Supported on Nitrogen-doped Carbon Nanofibers
as Efficient Poisoning Catalysts for the Hydrogenation of Nitroarenes
Yukihiro Motoyama,*[a] Youngjin Lee,[b] Keita Tsuji,[b] Seong-Ho Yoon,[a] Isao Mochida,[a] and Hideo Nagashima[a]
cctc_201100135_sm_miscellaneous_information.pdf
Supporting Information
*************************************
Contents
1. General Methods
P-S2
2. Synthesis and Characterization of Pt/N-CNF-Hs
P-S2
3. Hydrogenation of Nitro Compounds
P-S5
4. Spectral Data of Aniline Derivatives
P-S6
5. Spectral Data of N-Aryl Hydroxylamine Derivatives
P-S8
6. References
P-S8
S
1
1. General Methods.
Anhydrous toluene was purchased from Kanto Chemical Co., Ltd., and used as received. Nitroarenes
1a–f
and
1h–m
were
purchased
from
Tokyo
Chemical
Industry
Co.,
Ltd.
3-Chloro-4-benzyloxynitrobenzene (1g) was purchased from Aldrich Chemical Company, Inc. 1H and 13C
NMR spectra were measured on JEOL ECA 270 (270 MHz), ECA 400 (396 MHz) and ECA 600 (600
MHz) spectrometers. Chemical shifts for 1H NMR were described in parts per million downfield from
tetramethylsilane as an internal standard (δ = 0) in CDCl3, unless otherwise noted. Chemical shifts for 13C
NMR were expressed in parts per million in CDCl3 as an internal standard (δ = 77.1), unless otherwise
noted. IR spectra were measured on JASCO FT/IR-4200 spectrometer. GC analyses were performed on a
Shimadzu GC-17A gas chromatograph equipped with TC-1 (30 m) column. ICP-MS and HRMS analyses
were performed at the Analytical Center in Institute for Materials Chemistry and Engineering, Kyushu
University. Analytical thin-layer chromatography (TLC) was performed on aluminum sheets precoated
with aluminum oxide (Merck, aluminum oxide 150 F254, neutral) and glass plates precoated with silica gel
(Merck, Kieselgel 60 F254). Visualization was accomplished by UV light (254 nm), anisaldehyde, and
phosphomolybdic acid. N(5%)-CNF-H was prepared by the method reported previously.1 Pt(dba)2 was
prepared by the literature method.2
2. Synthesis and Characterization of Pt/N-CNF-Hs.
ICP-MS Analysis: The Pt catalyst prepared as above (10 mg) was added to an aqueous HCl solution
(12 mol/L, 10 mL). After the resultant suspension was heated at 70 °C for 20 h, the insoluble carbon
materials were removed by filtration using membrane filters (Durapore®; 0.45 mm HV). The obtained
supernatant was diluted with an aqueous solution of HCl, and the concentration of HCl was adjusted to 1.2
x 10-4 mol/L. The platinum contents on N-CNF-H and CNF-H were calibrated with a commercially
available standard reagent (ACROS: Pt atomic absorption standard solution, 1 mg/mL Pt in 10% HCl); five
standard solutions, of which Pt concentration is in a rage from 5 ppb to 200 ppb, were used for calibration.
TEM Studies: A few drops of a suspension of each sample in n-butanol were deposited on the TEM
grid (STEM 150 Cu grid, 150 mm), and the solvent was removed at room temperature under reduced
pressure (0.04 Torr). TEM observations were carried out with a JEOL JEM 2010F transmission electron
microscope operating at 200 kV. The particle size distributions were obtained from the TEM images using
a digital camera.
XPS Measurements: XPS spectra were obtained on a JEOL ESCA photoelectron spectrometer
(JPS-900MC) using monochromatic Mg Kα X-rays (10 kV, 10 mA). Base pressure in the spectrometer
was typically 9.8×10-8 Torr. An ion beam was focused to about 0.5 cm2 at normal incidence to the sample
surface at gas pressures of about 10-5 Torr. Peak positions were checked on well-characterized samples (In
foil 0.25 mm thick, 99.99%: 443.8 eV; purchased from WAKO Pure Chemical Ind., Ltd.).
S
2
Figure S1. TEM images and histgrams of the Pt particles of Pt/N-CNF-Hs and Pt/CNF-Hs.
N1s
402
401
C1s
400
399
398
397
293
O 1s
In 3d3/2
C 1s
In 3d5/2
289
77
76
287
285
283
75
74
73
72
500
400
71
70
Pt 4d
Pt 4f
600
281
Pt4f
78
N 1s
291
300
200
In 4d
100
0
Figure S2. XPS spectra of Pt(3%)/N-CNF-H.
S
3
O 1s
In 3d3/2
In 3d5/2
Pt4f
C 1s
78
77
76
75
74
73
72
71
70
N 1s
Pt 4d
In 4d
Pt 4f
Pt(1%)/N-CNF-H
600
500
In 3d3/2
O 1s
400
300
C 1s
In 3d5/2
200
100
0
Pt4f
78
77
76
75
74
73
72
71
70
Pt 4d
Pt 4f
Pt(3%)/CNF-H
600
500
In 3d3/2
400
300
200
In 4d
100
0
In 3d5/2
C 1s
Pt4f
O 1s
78
77
76
75
74
73
72
71
70
Pt 4d
Pt 4f
Pt(1%)/CNF-H
600
500
400
300
200
In 4d
100
0
Figure S3. XPS spectra of Pt(1%)/N-CNF-H, Pt(3%)/CNF-H, and Pt(1%)/CNF-H.
S
4
3. Hydrogenation of Nitro Compounds.
Gram-Scale Reaction of 4-Chloronitrobenzene (1b): Hydrogenation was performed in a 100 mL
stainless autoclave fitted with a glass inner tube, in the presence of 4-chloronitrobenzene 1b (1.26 g, 8.0
mmol), Pt(3%)/N-CNF-H [5 mg, S/C = 10,400 mol (1b)/ mol (Pt)] and ethyl acetate (10 mL) at room
temperature under H2 (initial pressure = 10 atm). After it was stirred for 12 h, the insoluble catalyst was
filtered off, and the filtrate was concentrated under reduced pressure to give 4-chloroaniline 2b in 99%
yield (1.00g). mp. 68.0-68.7 °C.
Recycle Experiments and ICP-MS Analysis of the Product: After the hydrogenation of
4-nitroanisole 1a over Pt(3%)/N-CNF-H [5 mg, S/C = 1,300 mol (1a)/ mol (Pt)], the recovered catalyst was
dried under reduced pressure and subjected to a further run of reduction of 1a (Table S1).
Table S1.
Run
1
2
3
4
5
Yield (%)
>99
>99
>99
>99
93
Pt amounts in 2a
Not detected
Not detected
Not detected
Not detected
Not detected
The platinum content in 4-aminoanisole 2a was determined by ICP-MS analysis: 2a obtained by the
above procedure was dissolved in an aqueous solution of HNO3, and the concentration of HNO3 was
adjusted to 1.3 x 10-4 wt%. The content of 2a in this solution was 1.0 x 10-4 mol/L. The measurement was
performed using this solution. The platinum content was calibrated with a commercially available standard
reagent (ACROS: platinum atomic absorption standard solution, 1 mg/mL Pt in 10% HCl); five standard
solutions, of which Pt concentration is in a range from 5ppb to 200ppb, were used for calibration.
Hydrogenation of 4-Nitrobenzonitrile (1l) to N-(4-Cyanophenyl) Hydroxylamine (3l) (Table 2,
Entry 3): Hydrogenation was performed in a 100 mL stainless autoclave fitted with a glass inner tube, in
the presence of 4-cyanonitrobenzene 1l (148.1 mg, 1 mmol), Pt(1%)/N-CNF-H (5 mg) and ethyl acetate (3
mL) at room temperature under H2 (initial pressure = 7 atm). After it was stirred for 4 h at 70 °C, the
insoluble catalyst was filtered off, and the filtrate was concentrated under reduced pressure. Purification of
the crude product by silica gel chromatography gave N-(4-cyanophenyl) hydroxylamine 3l in 94% yield.
S
5
4. Spectral Data of Aniline Derivatives.
4-Aminoanisole (2a):3,4 Colorless solid; mp: 57.0-57.7 °C; IR (KBr): ν 3427, 3335, 3221, 3073, 3007,
H2N
OMe
2964, 2938, 2912, 1844, 1631, 1499, 1440, 1234, 1129, 1040, 829, 644 cm-1; 1H
NMR (396 MHz, CDCl3): δ 3.42 (bs, 2H), 3.75 (s, 3H), 6.65 (d, J = 8.7 Hz, 2H),
6.75 (d, J = 8.7 Hz, 2H); 13C NMR (99.5 MHz, CDCl3): δ 55.7, 114.8, 116.4, 140.0,152.8; GLC (TC-17,
30 m, detection FID, column temp. 170 °C, tR = 8.1 min (1a), 13.8 min (2b).
4-Chloroaniline (2b):3 Colorless solid; mp: 68.1-68.7 °C; IR (KBr): ν 3475, 3376, 3201, 1678, 1616,
H2N
1506, 1286, 1179, 1083, 1008, 815, 639 cm-1; 1H NMR (396 MHz, CDCl3): δ 3.65 (bs,
Cl
2H), 6.61 (d, J = 8.7 Hz, 2H), 7.10 (d, J = 8.7 Hz, 2H); 13C NMR (99.5 MHz, CDCl3):
δ 116.2, 123.0, 129.1, 145.0; GLC (TC-17, 30 m, detection FID, column temp. 170 °C), tR = 8.8 min (2b),
9.2 min (1a).
3-Chloroaniline (2c):5 Colorless liquid; IR (neat): ν 3443, 3362, 3214, 3057, 1620, 1597, 1484, 1301,
1266, 1162, 1077, 992, 888, 850, 770, 681 cm-1; 1H NMR (396 MHz, CDCl3): δ 3.71 (bs,
Cl
2H), 6.54 (ddd, J = 8.2, 2.4, 1.0 Hz, 1H), 6.67 (dd, J = 2.4, 1.9 Hz, 1H), 6.72 (ddd, J = 7.7,
H2N
1.9, 1.0 Hz, 1H), 7.06 (dd, J = 8.2, 7.7 Hz, 1H);
13
C NMR (99.5 MHz, CDCl3): δ 113.1,
114.8, 118.2, 130.3, 134.6, 146.7; GLC (TC-17, 30 m, detection FID, column temp. 170 °C), tR = 8.9 min
(2c), 9.1 min (1c).
2-Chloroaniline (2d):6 Colorless liquid; IR (neat): ν 3469, 3379, 3198, 3070, 3025, 1603, 1451, 1306,
1158, 1077, 1023, 835, 678 cm-1; 1H NMR (396 MHz, CDCl3): δ 4.03 (bs, 2H), 6.92 (m,
Cl
1H), 6.77 (dm, J = 7.7 Hz, 1H), 7.07 (m, 1H), 7.24 (dm, J = 8.2 Hz, 1H); 13C NMR (99.5
H2N
MHz, CDCl3): δ 115.8, 118.9, 119.2, 127.6, 129.3, 142.9; GLC (TC-17, 30 m, detection
FID, column temp. 170 °C, tR = 8.8 min (2d), 9.2 min (1d).
4-Bromoaniline (2e):3 Colorless solid; mp 60.5-61.6 °C; IR (KBr): ν 3476, 3384, 3184, 1877, 1607, 1488,
H2N
1288, 1180, 1121, 1061, 829 cm-1; 1H NMR (396 MHz, CDCl3): δ 3.66 (bs, 2H), 6.56
Br
(d, J = 8.7 Hz 2H), 7.23 (d, J = 8.7 Hz, 2H); 13C NMR (99.5 MHz, CDCl3): δ 110.1,
116.7, 132.0, 145.5; GLC (TC-17, 30 m, detection FID, column temp. 170 °C, tR = 9.8 min (2e), 10.6 min
(1e).
4-Iodoaniline (2f):3 Colorless solid; mp 60.7-61.4 °C; IR (KBr): ν 3406, 3300, 3203, 3058, 3028, 1871,
H2N
I
1629, 1581, 1482, 1274, 1176, 997, 682 cm-1; 1H NMR (396 MHz, CDCl3): δ 3.67(bs,
2H), 6.47 (d, J = 8.2 Hz, 2H), 7.41 (d, J = 8.2 Hz, 2H); 13C NMR (99.5 MHz, CDCl3): δ
79.4, 117.3, 137.9, 146.1; GLC (TC-17, 30 m, detection FID, column temp. 170 °C, tR = 18.7 min (2f),
19.3 min (1f).
4-Benzyloxy-3-chloroaniline (2g):5 Colorless solid; mp: 57.3-58.1 °C; IR (KBr): ν 3406, 3299, 3199,
Cl
H2N
3062, 3032, 2908, 2861, 1628, 1504, 1375, 1269, 1224, 1051, 1010, 915, 852, 739,
OBn
S
6
693 cm-1; 1H NMR (396 MHz, CDCl3): δ 3.48 (bs, 2H), 5.05 (s, 2H), 6.50 (dd, J = 8.7, 2.9 Hz, 1H), 6.76 (d,
J = 2.9 Hz, 1H), 6.80 (d, J = 8.7 Hz, 1H), 7.31 (t, J = 7.2 Hz, 1H), 7.38 (t, J = 7.2 Hz, 2H), 7.45 (d, J = 7.2
Hz, 2H);
13
C NMR (99.5 MHz, CDCl3): δ 72.2, 114.2, 117.0, 117.2, 124.4, 127.4, 127.9, 128.5, 137.1,
141.4, 147.1.
3-Carbomethoxy-4-chloroaniline (2h):7 Yellow liquid; IR (neat): ν 3466, 3376, 3226, 3000, 2951, 2841,
H2N
CO2Me
1724, 1626, 1601, 1482, 1440, 1323, 1241, 1121, 1042, 978, 824, 780, 652 cm-1; 1H
Cl
NMR (396 MHz, CDCl3): δ 3.76 (bs, 2H), 3.91 (s, 3H), 6.72 (dd, J = 8.7, 2.9 Hz,
1H), 7.12 (d, J = 2.9 Hz, 1H), 7.20 (d, J = 8.7 Hz, 1H);
13
C NMR (99.5 MHz,
CDCl3): δ 52.4, 117.2, 119.1, 122.0, 130.3, 131.6, 145.1, 166.5.
Ethyl 4-aminobenzoate (2i):4 Pale orange solid; mp: 88-89 °C; IR (KBr): ν 3422, 3342, 3222, 2984, 2957,
H2N
CO2Et
2899, 1916, 1683, 1635, 1596, 1513, 1474, 1441, 1367, 1311, 1172, 1109, 1024, 845,
772, 700 cm-1; 1H NMR (396 MHz, CDCl3): δ 1.36 (t, J = 7.2 Hz, 3H), 4.03 (bs, 2H),
4.32 (q, J = 7.2 Hz, 2H), 6.64(d, J = 8.7 Hz, 2H), 7.86 (d, J = 8.7 Hz, 2H); 13C NMR (99.5 MHz, CDCl3): δ
14.4, 60.3, 113.8, 119.9, 131.6, 150.9, 166.8; GLC (TC-17, 30 m, detection FID, column temp. 170 °C, tR
= 18.5 min (2i), 27.3 min (1i).
4-Aminoacetophenone (2j):3 Colorless solid; mp 102.3-102.9 °C; IR (KBr): ν 3399, 3341, 3301, 2970,
H2N
COMe
2927, 2884, 1614, 1516, 1363, 1260, 1083, 998, 897, 780, 732 cm-1; 1H NMR
(396 MHz, CDCl3): δ 2.50 (s, 3H), 4.11 (bs, 2H), 6.65 (d, J = 8.7 Hz, 2H), 7.80 (d,
13
J = 8.7 Hz, 2H); C NMR (99.5 MHz, CDCl3): δ 26.1, 113.7, 127.8, 130.8, 151.3, 196.6; GLC (TC-17, 30
m, detection FID, column temp. 170 °C, tR = 16.5 min (2j), 22.3 min (1j).
Ethyl 4-aminocinnamate (2k):3 Pale yellow solid; mp 70.4-71.4 °C; IR (KBr): ν 3464, 3365, 3232, 2980,
CO2Et
H2N
1694, 1596, 1517, 1441, 1306, 1172, 1037, 983, 828 cm-1; 1H NMR (396 MHz,
CDCl3): δ 1.32 (t, J = 7.2 Hz, 3H), 3.92 (bs, 2H), 4.24 (q, J = 7.2 Hz, 2H), 6.24
(d, J = 15.9 Hz, 1H), 6.65 (d, J = 8.7 Hz, 2H), 7.35 (d, J = 8.7 Hz, 2H), 7.60 (d, J = 15.9 Hz, 1H);
13
C
NMR (99.5 MHz, CDCl3): δ 14.3, 60.2, 113.8, 114.9, 124.8, 129.9, 144.9, 148.8, 167.8.
4-Cyanoaniline (2l):3,4 Pale yellow solid; mp 85.2-85.7 °C; IR (KBr): ν 3477, 3370, 3212, 2213, 1625,
H2N
CN
1601, 1514, 1317, 1175, 831, 696 cm-1; 1H NMR (396 MHz, CDCl3): δ 4.14 (bs, 2H),
6.65 (d, J = 8.2 Hz, 2H), 7.42 (d, J = 8.2 Hz, 2H);
13
C NMR (99.5 MHz, CDCl3): δ
100.2, 114.5, 120.3, 133.8, 1580.5.
2-(Cyanomethyl)aniline (2m):8 Colorless solid; mp: 69.1-69.7 °C; IR (KBr): ν 3111, 3111, 2980, 2853,
2243, 1612, 1530, 1412, 1344, 1189, 1079, 860, 795, 737 cm-1; 1H NMR (396 MHz,
CDCl3): δ 3.57 (s, 2H), 3.68 (bs, 2H), 6.75 (d, J = 7.7 Hz, 1H), 6.82 (dd, J = 7.7, 7.3 Hz,
1H), 7.13-7.24 (m, 2H); 13C NMR (99.5 MHz, CDCl3): δ 20.2, 115.0, 116.8, 117.3, 119.6,
129.5, 129.6, 144.2.
S
7
5. Spectral Data of N-Aryl Hydroxylamine Derivatives.
N-(4-Ethoxycarbonylphenyl) hydroxylamine (3i):9,10 Colorless solid; mp: 92.5-93.5 °C; IR (KBr): ν
HOHN
CO2Et
3370, 3298, 2982, 1694, 1682, 1606, 1509, 1464, 1392, 1369, 1307, 1282, 1171,
1108, 1022, 881, 850, 773, 699 cm-1; 1H NMR (396 MHz, CDCl3): δ 1.38 (t, J
= 7.2 Hz, 3H), 4.35 (q, J = 7.2 Hz, 2H), 5.36 (bs, 1H), 6.97 (bs, 1H), 6.98 (d, J = 8.7 Hz, 2H), 7.97 (d, J =
8.7 Hz, 2H);
13
C NMR (67.8 MHz, CDCl3): δ 14.4, 60.8, 113.0, 123.5, 131.0, 154.0, 166.9; HRMS (EI)
calcd for C9H11NO3 181.0739, found 181.0736.
N-(4-Acetylphenyl) hydroxylamine (3j):9,10 Colorless solid; mp: 122-123 °C; IR (KBr): ν 3286, 1640,
HOHN
COMe
1594, 1395, 1287, 1177, 879, 836, 753, 669 cm-1; 1H NMR (600 MHz, CDCl3):
δ 2.56 (s, 3H), 5.32 (bs, 1H), 6.99 (bs, 1H), 7.00 (d, J = 8.3 Hz, 2H), 7.92 (d, J
= 8.3 Hz, 2H); 13C NMR (150 MHz, CDCl3): δ 26.4, 113.0, 130.1, 131.1, 154.1, 197.0; HRMS (EI) calcd
for C8H9NO2 151.0633, found 151.0635.
N-(4-Cyanophenyl) hydroxylamine (3l):10 Colorless solid; mp: 83.8-84.7 °C; IR (KBr): ν 3291, 3205,
HOHN
CN
2943, 2894, 2852, 2222, 1609, 1508, 1423, 1178, 1026, 869, 833, 763, 672 cm-1; 1H
NMR (270 MHz, CDCl3): δ 5.23 (bs, 1H), 6.99 (bs, 1H), 7.01 (d, J = 8.7 Hz, 2H),
7.55 (d, J = 8.7 Hz, 2H); 13C NMR (67.8 MHz, CDCl3): δ 104.2, 113.7, 119.6, 133.4, 153.7; HRMS (EI)
calcd for C7H6N2O 134.0480, found 134.0474.
6. References
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H. Rao, H. Fu, Y. Jiang, Y. Zhao, Angew. Chem. Int. Ed. 2009, 48, 1114-1116.
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K. Kondo, H. Ogawa, H. Yamashita, H. Miyamoto, M. Tanaka, K. Nakaya, K. Kitano, Y. Yamamura,
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Z. Rong, W. Du, Y. Wang, L. Lu, Chem. Commun. 2010, 46, 1559-1561.
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8