Organometallics
ARTICLE
the monomeric form in the molecularly dissolved state. Similar
concentration- and temperature-dependent behavior was also
observed in the emission spectrum of C2 in hexane (Figures S24
and S25, Supporting Information).
Anal. Calcd for C176H290O12P8Pt4: C, 58.29; H, 8.06. Found: C, 58.30;
H, 8.05.
Synthesis of Compound C2. Following the procedure for C1, 15
(100.0 mg, 0.04 mmol), 6b (203.2 mg, 0.32 mmol), cuprous iodide
(3.0 mg, 10 mol %), Et2NH (4 mL), and dried THF (4 mL) yielded
C2 as a wheat-colored solid (180 mg, 98.4%) after purification by
column chromatography on silica gel (acetone/petroleum ether 1/7).
Mp: 117 °C. 1H NMR (CDCl3, 400 MHz): δ 0.88 (t, 36H, J = 6.4 Hz),
1.17À1.37 (m, 264H), 1.43À1.44 (m, 24H), 1.70À1.79 (m, 24H),
2.15À2.16 (m, 48H), 3.90 À3.94 (m, 24H), 6.47 (s, 8H), 7.17 (s, 6H).
13C NMR (CDCl3, 100 MHz): δ 8.35, 14.10, 16.10, 16.27, 16.45, 22.67,
26.10, 29.35, 29.37, 29.37, 29.42, 29.64, 29.68, 29.71, 29.73, 30.27, 31.90,
69.01, 73.45, 105.28, 105.43, 105.59, 108.24, 108.67, 108.83, 108.98,
109.68, 121.03, 123.48, 131.39, 136.96, 152.57. 31P NMR (CDCl3, 161.9
MHz): δ 11.61 (JPtÀP = 2365.4 Hz). HR CSI-TOF-MS of C2: m/z
2319.1 [M + 2H]2+. Anal. Calcd for C248H434O12P8Pt4: C, 64.25; H,
9.44. Found: C, 64.53; H, 9.34.
’ CONCLUSION
In summary, a series of platinum acetylide derivatives featuring
linear, triangular, and rectangular shapes have been successfully
synthesized. It was found that they displayed unexpectedly
different gelation behavior. For example, linear molecules A
and triangular molecules B formed gels only with difficulty, while
rectangular molecules C1 and C2 exhibited very high gel forma-
tion efficiency in most organic solvents, even at concentrations as
low as 2.0 and 5.8 mg/mL, respectively. Again, all these results
indicate that the structural factors, including the shape of the
gelator molecules and the number of the side alkyl chains, play an
essential role during the formation of the supramolecualr gels,
although it has not been well understood up to date. In con-
clusion, we have reported the synthesis of a series of platinum
acetylide derivatives, which presented different gel formation
properties. This research obviously enriches the library of orga-
nometallic gels and might be helpful in gaining further insight
into the structural requirements for organometallic gelators.
’ ASSOCIATED CONTENT
S
Supporting Information. Text, tables, and figures giving
b
details of synthesis and characterization of the compounds and
supplementary experimental data. This material is available free
’ AUTHOR INFORMATION
’ EXPERIMENTAL SECTION
Corresponding Author
*E-mail: hbyang@chem.ecnu.edu.cn.
The target molecules C1 and C2 were prepared by a six-step synthetic
scheme as shown in Scheme S3 (see Supporting Information). Com-
pounds 10À14 and 6 were prepared according to previously reported
synthetic procedures3f,5cÀ5e,8 and showed spectroscopic properties
identical with those reported therein.
’ ACKNOWLEDGMENT
H.-B.Y. thanks the NSFC (Nos. 91027005 and 20902027),
Shanghai Pujiang Program (No. 09PJ1404100), Shanghai
Shuguang Program (No. 09SG25), Innovation Program of
SMEC (No. 10ZZ32), RFDP (No. 20100076110004) of Higher
Education of China, and “the Fundamental Research Funds
for the Central Universities” for financial support. We thank
professor Jun-Li Hou (Fudan University) for his help with SEM
and TEM measurements.
Synthesis of Compound 15. A solution of trans-diiodobis-
(triethylphosphine)platinum (1.32 g, 1.93 mmol) and cuprous iodide
(14.7 mg, 8 mol %) in a THF/Et2NH mixture (20 mL/10 mL) was
stirred at room temperature, and 14 (72.0 mg, 0.24 mmol) dissolved in
THF (10 mL) was added dropwise for 0.5 h. After another 1 h a small
amount of diethylammonium iodide started precipitating out of solu-
tion. The solvent was removed in vacuo. The yellow-red residue was
separated by column chromatography on silica gel (dichloromethane/
petroleum ether 3/2) to give the desired product 15 as a wheat-colored
solid. Yield: 390 mg, 64%. Mp: 222 °C. 1H NMR (300 MHz, CDCl3): δ
1.11À1.22 (m, 72H), 2.19 À2.23 (m, 48H), 7.17 (s, 2H), 7.21 (s, 4H).
13C NMR (75 MHz, CDCl3): δ 8.10, 8.24, 8.39, 16.12, 16.34, 16.57,
16.81, 17.03, 73.42, 81.44, 91.14, 91.33, 91.52, 98.95, 121.36, 128.47,
128.71, 128.93, 131.38, 133.72. 31P NMR (121 MHz, CDCl3): δ 9.10
(JPtÀP = 2309.9 Hz). Anal. Calcd for C72H126I4P8Pt4: C, 34.21; H, 5.02.
Found: C, 34.60; H, 5.12.
Synthesis of Compound C1. A 100 mL Schlenk flask was charged
with 15 (100.0 mg, 0.04 mmol), 6a (125.7 mg, 0.32 mmol), and cuprous
iodide (3.0 mg, 10 mol %), degassed, and back-filled three times with N2.
Et2NH (4 mL) and dried THF (4 mL) were introduced into the reaction
flask by syringe. The reaction mixture was stirred under an inert
atmosphere at room temperature for about 4 h. The solvent was
removed by evaporation on a rotary evaporator. The residue was purified
by column chromatography on silica gel (acetone/petroleum ether 1/7)
to give C1 (124.2 mg, 86.6%) as a wheat-colored solid. Mp: 110 °C. 1H
NMR (CDCl3, 400 MHz): δ 0.89 (br, 36H), 1.17À1.28 (m, 72H), 1.32
(br, 48H), 1.45 (br, 24H), 1.70À1.79 (m, 24H), 2.15À2.17 (m, 48H),
3.90 À3.95 (m, 24H), 6.48 (s, 8H), 7.18 (s, 6H). 13C NMR (CDCl3, 100
MHz): δ 8.35, 14.00, 16.13, 16.30, 16.48, 22.59, 29.32, 30.19, 31.55,
31.73, 69.00, 73.42, 105.38, 108.20, 109.66, 121.06, 123.48, 128.74,
131.38, 134.31, 136.99, 152.59. 31P NMR (CDCl3, 161.9 MHz): δ 11.64
(JPtÀP = 2365.4 Hz). HR CSI-TOF-MS of C1: m/z 1814.0 [M + 2H]2+.
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