and used without further purification. The solvents were dried using the standard method and stored over 4 Å molecular sieves prior to use.
Melting points were measured using an MEL-TEMP II melting point apparatus and are uncorrected. 1H and 13C NMR spectra were recorded at 300 and 75 MHz, respectively, using a Varian Unity Plus 300 spectrometer. The high-resolution mass spectral data (ESI) were obtained using a Waters SYNAPT G2 mass spectrometer. Absorption spectra were measured using a Varian Cary 300 UV–VIS spectrophotometer, and the fluorescence measurements were carried out using a Horiba dual-FL fluorescence spectrophotometer.
2.2 Synthesis of 3-(anthracen-9-ylmethyl)-1,1-dimethylguanidine …show more content…
The pH value of the sample solution was slightly changed by adding a small amount of HCl or NaOH. All the fluorescence measurements with pH changes were performed at an excitation at 367 nm in the presence of NaCl (0.1 M) to maintain a constant ionic strength.
Prior to each water content measurement, the sample solutions with an AMG concentration of 2.0 × 10-5 M containing different water contents in organic solvents were prepared. Fluorescence was measured at an excitation wavelength at 370 nm in 1,4-dioxane and 368 nm in DMF, CH3CN, and EtOH. The fluorescence peak intensities were observed at 414 nm for 1,4-dioxane, 415 nm for DMF, and 411 nm for CH3CN and