Information ( ESI ) Fluorescent “ Light-Up ” Bioprobes Based on Tetraphenylethylene Derivatives with Aggregation-Induced Emission Characteristics

Hui Tong, Yuning Hong, Yongqiang Dong, Matthias Häußler, Jacky W. Y. Lam, Zufeng Guo, Zhihong Guo, and Ben Zhong Tang* a Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China; Email: tangbenz@ust.hk; Phone: +852-2358-7375; Fax: +852-2358-1594 b Key Laboratory of Macromolecular Synthesis and Functionalization of the Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China

During this period, 10 mL of water was added at several intervals.THF and extra triethylamine were evaporated.The water solution was washed by chloroform three times.After solvent evaporation, the residue was washed with chloroform and acetone and then dried overnight in vacuo at 50 °C.The product (4) was isolated in 68% yield.

UV and PL Spectra
Stock solutions of 1 and 2 were 1.0 × 10 -3 M in acetonitrile.Sample mixtures for measuring the UV and PL spectra were prepared by adding 1 mL of a stock solution to 99 mL of acetonitrile or water under vigorous stirring at room temperature.The mixtures were stirred for half an hour prior to taking their spectra.The relative fluorescence quantum yields (Φ F ) were determined by the standard method using 1.0 × 10 -5 M quinine sulfate in 0.1N H 2 SO 4 solution as reference.The refractive indices of the solvents were taken into account in the measurements.
BSA was dissolved in a pH 7.0 phosphate buffer solution (1.0 mg/mL).DNA was dissolved in deionized water (1.0 mg/mL) and filtered through a 0.45 µm filter.The actual concentration (in nucleic base) was determined by UV photometry using the extinction coefficient ε 260 = 6600 M -1 cm -1 .
Stock solutions of 3 and 4 were 2.5 × 10 -4 M in water.Fluorescence titration was carried out by sequentially adding 100 µL aliquots of DNA or BSA solution to a 100 µL stock solution of 3 or 4, followed by adding an aqueous phosphate buffer (10 mM, pH 7) to acquire a 10.00 ml solution.The mixtures were stirred for half an hour prior to taking their spectra.

Temperature Effect on NMR Spectra
According to previous studies of rotation-induced conformational changes in many molecular systems, fast conformational exchanges caused by fast intramolecular rotations upon single-bond axes give sharp resonance peaks, whereas slower exchanges due to slowed rotations at lower temperatures broaden the resonance peaks.2 The dichloromethane solution of 1 exhibits sharp NMR peaks at room temperature, which are clearly broadened when the temperature is decreased (Figure S7).The solvent (dichloromethane) should be in the liquid state and experience little viscosity change in the whole measured temperature range (i.e., from 25 to -53 °C).Dye 1 should remain molecularly dissolved at the temperatures and the effects of aggregate formation and viscosity change should be marginally small.The plot of Ln δ fwhm (full width at half maximum) versus 1/T is a linear line (Figure S8), suggesting that the band shape broadening follows a single mechanism.The restriction of intramolecular rotations is thus believed to be the predominant factor for the band shape broadening. 3 To a mixture of sodium hydride (84 mg)