Controlled Growth of Cubic Cadmium Sulfide Nanoparticles Using Patterned Self-Assembled Monolayers as a Template
✍ Scribed by C.-C. Chen; J.-J. Lin
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 339 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0935-9648
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✦ Synopsis
The white solid is dissolved in CH 2 Cl 2 and the solution is evaporated very slowly at room temperature. After one day, a crystalline solid, 2, precipitated and was separated by filtration. 1 H NMR of 2: (CDCl 3 ) d (ppm): 7.15 (dd, 2H, J = 7.8 Hz and J m = 1.8 Hz), 6.50 (d, 2H, J m = 1.8 Hz), 6.45 (d, 2H, J = 7.8 Hz), 3.15 (m, 8H, ±CH 2 ±).
The solution of petroleum ether obtained after filtration of 2 is evaporated. The residue is purified by column chromatography with light petroleum±CH 2 Cl 2 (9:1) as eluent. Two products are isolated. The first one that elutes is a dibromocyclophane 3 (isomer of 2). The second product is a monobromocyclophane 4. 1 H NMR of 3: (CDCl 3 ) d (ppm): 7.15 (d, 2H, J = 7.8 Hz), 6.58 (d, 2H, J m = 1.8 Hz), 6.45 (dd, 2H, J = 7.8 Hz and J m = 1.8 Hz), 3.10 (m, 8H, ±CH 2 ±). 1 H NMR of 4: (CDCl 3 ) d (ppm): 7.15 (dd, 1H, J = 7.9 Hz and J m = 1.8 Hz, H aromatic), 6.50 (m, 6H, H aromatic), 3.46 (ddd, 1H, J = 2.3 Hz and J = 10.0 Hz and J = 12.2 Hz, ±CH±), 3.00 (m, 7H, 7-CH±).
Procedure for the Synthesis of 5-Trimethyltin-2,2¢-bithiophene 5: 500 mg (3 mmol) of 2,2¢-bithiophene are dissolved in 10 mL of tetrahydrofuran (THF). 1.9 mL of butyllithium (1.6 M in hexane) (3 mmol) is added to the solution at 0 C. After 1 h of stirring, 3 mL of trimethyltin chloride (1 M in THF) (3 mmol) are added to the mixture at 0 C. The solution is stirred at room temperature for two hours. The solvent is evaporated and the residue is hydrolyzed with 20 mL of water. The aqueous layer is extracted with ether. The organic layer is then dried over anhydrous sodium sulfate and the solvent is removed under reduced pressure. The residue is used without further purification because 4 is very sensitive to acidic conditions. Yield = 75 %