Supplementary Material for
Room–Temperature Single Molecular Memory
Shinya Kano,1,4 Yasuyuki Yamada,2,4 Kentaro Tanaka,3,4 and Yutaka Majima1,4,5*
1
Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
2
Research Center for Materials Science, Nagoya University, Nagoya, 464-8602, Japan
3
Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, 464-8602,
Japan
4
CREST, Japan Science and Technology Agency, Yokohama, 226-8503, Japan
5
Department of Printed Electronics Engineering, Sunchon National University, Sunchon, 540-742,
Republic of Korea
*E-mail: majima@msl.titech.ac.jp
Page 2:
General Methods.
Page 3:
Scheme S1.
Page 4–6:
Page 7:
Synthesis and Characterization of Compounds 2, 4, 5, 6, and 7.
References.
S1
General Methods.
Synthetic procedures were carried out under dry nitrogen atmosphere, unless otherwise specified.
All reagents and solvents were purchased at the highest commercial quality available and used
without
further
purification,
2-[[2-(acetyloxy)ethyl]dithio]ethyl
unless
ester
1
otherwise
1
and
stated.
p-Toluenesulfonic
2-(t-butyloxycarbonylamino)ethylamine2
4-(ethoxycarbonylmethoxy)benzaldehyde3 3 were prepared according to literature procedures.
13
acid,
1
1
H,
13
C spectra were recorded on a JEOL JNM-A400 (400 MHz for H; 100 MHz for C) spectrometer
at a constant temperature of 298 K.
1
H and
13
Tetramethylsilane (TMS) was used as an internal reference for
C NMR measurements in CDCl3. Elemental analyses were performed on a Yanaco MT-6
analyzer. Silica gel column chromatographies and thin-layer (TLC) chromatography were performed
using Merck silica gel 60 and Merck silica gel 60 (F254) TLC plates, respectively. GPC was
performed using a JAI LC-9204 equipped with JAIGEL 1H-40/2H-40 columns. ESI mass
spectrometry was performed with a Waters LCT-Premier XE Spectrometer controlled using
Masslynx software.
FAB mass spectrometry was performed with a JEOL JMS-700 Spectrometer.
S2
Scheme S1. Synthesis of a Cu(II) porphyrin ( Boc-Por-SS1(Cu) ) 7.
S3
Synthesis of Acetyl 2-[2-[2-(t-butyloxycarbonylamino)ethylamino]ethyldithio]ethyl ester (2)
To a solution of 2-(t-butyloxycarbonylamino)ethylamine2 (3.9 g, 24 mmol) in anhydrous CH3CN
(20 mL) was added dropwise a solution of p-toluenesulfonic acid, 2-[[2-(acetyloxy)ethyl]dithio]ethyl
ester1 1 (1.5 g, 4.3 mmol) in anhydrous CH3CN (20 mL) at 40 °C over 15 min. The reaction mixture
was stirred at 40 °C for 22 hrs and then concentrated to obtain a pale yellow residue. The residue
was dissolved in AcOEt (200 mL) and the solution was washed with saturated aqueous Na2CO3 (100
mL), H2O (100 mL) and brine (100 mL), dried over anhydrous MgSO4, filtered, and concentrated
under reduced pressure to afford a pale yellow oil (5.2 g). The crude product was purified by silica
gel column chromatography (5 cm   21 cm, CH2Cl2 : MeOH = 9 : 1) to afford the title compound 4
as a colorless oil (0.93 g, 2.8 mmol, 64%).
1
IR (ATR/ZnSe): 3343, 2975, 2931, 1738, 1695 cm–1.
H NMR (400 MHz, CDCl3/TMS):  = 5.02 (br, 1H), 4.33 (d, J = 6.7 Hz, 2H), 3.23 (br, 2H), 2.93 (m,
4H), 2.84 (t, J = 6.1 Hz, 2H), 2.75 (t, J = 5.7 Hz, 2H), 2.08 (s, 3H), 1.45 (s, 9H).
13
MHz, CDCl3):  = 170.9, 156.1, 79.2, 62.4, 48.6, 47.4, 40.2, 38.9, 37.0, 28.4, 20.9.
MS (ESI-TOF,
C NMR (100
+
positive) m/z 339.1: calcd for C13H27N2O4S2 ([2+H] ), found: 339.1.
Synthesis of 5,10,15,20-[Tetra(4-Ethoxycarbonylmethyloxy)phenyl]porphyrin (4)
A solution of 4-(ethoxycarbonylmethoxy)benzaldehyde3 3 (2.1 g, 10 mmol) and pyrrole (0.67 g, 9.7
mmol) in CH2Cl2 (500 mL) was deoxygenated by N2 bubbling for 30 min. Trifluoroacetic acid (0.75
mL, 10 mmol) was added dropwise within 5 min. The resulting solution was stirred at room
temperature for 30 min. After 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ, 3.4 g, 15 mmol) and
Et3N (3.0 mL, 20 mmol) were added successively, the mixture was stirred for 2 hrs and then
concentrated approximately to the half volume. The resulting solution was filtered through a celite
pad and concentrated to give a residual black solid. The crude product was purified by silica gel
column chromatography (5 cm  30 cm, CH2Cl2) followed by reprecipitation (hexane / CHCl3) to
afford the title compound 7 as a purple solid (1.1 g, 1.1 mmol, 43%).
1758 cm–1.
1
IR (ATR/ZnSe): 3452, 2873,
H NMR (400 MHz, CDCl3):  = 8.85 (s, 8H), 8.13 (d, J = 8.4 Hz, 8H), 7.30 (d, J = 8.4
Hz, 8H), 4.92 (s, 8H), 4.42 (q, J = 7.2 Hz, 8H), 1.42 (t, J = 7.2 Hz, 12H), –2.80 (s, 2H).
(100 MHz, CDCl3):  = 169.0, 157.7, 135.5, 131.0 (br), 112.9, 65.7, 61.5, 14.2.
+
positive) m/z 1023.4: calcd for C60H55N4O12 ([4+H] ), found: 1023.4.
S4
13
C NMR
MS (ESI-TOF,
Synthesis of 5,10,15,20-Tetra[(4-carboxymethyloxy)phenyl]-porphyrin (5)
5,10,15,20-Tetra[(4-ethoxycarbonylmethyloxy)phenyl]porphyrin 4 (826 mg, 0.81 mmol) was
dissolved in a mixture of THF (50 mL) and 3 M aqueous KOH (20 mL) and the resulting solution was
stirred at the bath temperature of 50 °C for 6 hrs.
After the mixture was cooled to room temperature,
the pH of the solution was adjusted to approximately 4 with 1 M aqueous HCl. The resulting green
precipitate was collected by centrifugation, washed with H2O (50 mL  2) and MeOH (50 mL), and
then dried under vacuum to afford the title compound as a green solid (551 mg, 0.61 mmol, 75%).
IR (ATR/ZnSe): 3121, 1597 cm–1.
1
H NMR (400 MHz, DMSO-d6):  = 13.20 (br, 4H), 8.86 (s, 8H),
8.14 (d, J = 8.4 Hz, 8H), 7.37 (d, J = 8.4 Hz, 8H), 4.99 (s, 8H), –2.91 (s, 2H).
MS (ESI-TOF,
+
positive) m/z 911.3: calcd for C52H39N4O12 ([5+H] ), found: 911.3.
Synthesis of a Porphyrin ( Boc-Por-SS1 ) (6)
A solution containing a porphyrin 5 (504 mg, 0.55 mmol), acetyl 2-[2-[2-(t-butyloxycarbonyl
amino)ethylamino]ethyldithio]ethyl ester 2 (934 mg, 2.76 mmol), DCC (570 mg, 2.77 mmol),
HOBt·H2O (379 mg, 2.80 mmol), and diisopropylethylamine (1.0 mL, 5.74 mmol) in anhydrous DMF
(20 mL) was stirred at room temperature for 65 hrs. After the volatile compounds were distilled off,
the resulfing purple residue was dissolved in AcOEt (300 mL). The organic layer was washed with
saturated aqueous Na2CO3 (100 mL), H2O (100 mL  3) and brine (100 mL), dried over anhydrous
Na2SO4, filtered, and evaporated.
The crude product was purified by silica gel column
chromatography (5 cm  22 cm, AcOEt) to afford purple solid (942 mg), which was further purified
by GPC to give the title compound 7 as a purple solid (869 mg, 0.40 mmol, 72%).
3315, 2979, 1692, 1656 cm–1.
1
IR (ATR/ZnSe):
H NMR (400 MHz, CDCl3/TMS):  = 8.85 (s, 8H), 8.15–8.11 (m,
8H), 7.25–7.33 (m, 8H), 5.09–5.02 (m, 12H), 4.41–4.35 (m, 8H), 3.86 (t, J = 6.7 Hz, 4H), 3.78 (t, J =
6.8 Hz, 4H), 3.69 (t, J = 6.0 Hz, 4H), 3.62 (t, J = 6.0 Hz, 4H), 3.48–3.42 (m, 8H), 3.07–2.95 (m, 16H),
2.07 (s, 6H), 2.06 (s, 6H), 1.47 (s, 18H), 1.44 (s, 18H), –2.79 (s, 2H).
13
C NMR (100 MHz, CDCl3):
 = 170.9, 170.8, 168.8, 168.5, 157.8, 156.2, 156.0, 135.7, 135.6, 135.5, 131.0, 119.5, 119.4, 113.0,
113.0, 80.2, 79.5, 67.6, 67.1, 62.3, 62.1, 47.9, 47.6, 46.1, 46.0, 39.2, 38.9, 37.2, 36.9, 36.6, 35.5, 28.4,
20.9, 20.9.
MS (ESI-TOF, positive) m/z 2191.7: calcd for C104H135N12O24S8 ([6+H]+), found: 2191.8.
Anal. Calcd. for C104H134N12O24S8: C, 56.97; H, 6.16; N, 7.67. Found: C, 56.70; H, 6.21; N, 7.46.
S5
Synthesis of a Cu(II) Porphyrin ( Boc-Por-SS1(Cu) ) (7)
A porphyrin 6 (54 mg, 25 mol) and Cu(OAc)2 (5.6 mg, 31 mol) were dissolved in DMF (2.0
mL) and the resulting mixture was stirred at room temperature for 7 hrs.
After the mixture was
diluted with AcOEt (50 mL), the solution was washed with H2O (100 mL  6) and brine (100 mL),
dried over anhydrous Na2SO4, filtered, and evaporated. The crude product was purified by silica
gel column chromatography (2 cm  10 cm, AcOEt) followed by reprecipitation from
CHCl3/hexane to afford the title compound as a reddish purple solid (51 mg, 22 mol, 91%).
–1
(ATR/ZnSe): 2979, 1693, 1657 cm .
IR
MS (ESI-TOF, positive) m/z 2274.6: calcd for
+
C104H132CuNaN12O24S8 ([6+Na] ), found: 2274.6.
Anal. Calcd. for C104H132CuN12O24S8: C, 54.97;
H, 5.94; N, 7.40. Found: C, 54.96; H, 5.88; N, 7.23 (0.17% Error).
S6
References.
1.
L. Azéma, C. Lherbet, C. Baudoin, and C. Blonski, Bioorg. Med. Chem. Lett. 16, 3440–3443
(2006).
2.
E. Baciocchi, C. Fabbri, and O. Lanzalunga, J. Org. Chem. 68, 9061–9069 (2003).
3.
J. Guy, K. Caron, S. Dufresne, S. W. Michnick, W. G. Skene, and J. W. Keillor, J. Am. Chem.
Soc. 129, 11969–11977 (2007).
S7