Accurate mass q tof ms 6520 system

Commercial reagents were obtained from J&K (Beijing, China), Alfa Aesar (Ward Hill, MA, USA) and Sigma-Aldrich (St. Louis, MO, USA). Deionized water was purified with a Milli-Q Plus System from Millipore (Billerica, MA, USA) was used throughout all experiments. Nuclear magnetic resonance (NMR) spectra were recorded with a 600-MHz spectrometer (Agilent Technologies, Inc., Santa Clara, CA, USA). Mass spectra were recorded with a UPLC/XevoTQ MS/MS spectrometer (Waters, Milford, MA, USA) and an Agilent Accurate-Mass-Q-TOF MS 6520 system equipped with an Electrospray ionization (ESI) source. Reactions were stirred magnetically and monitored by thin-layer chromatography (TLC). Flash chromatography was performed using silica gel 60 (200–300 mesh). UV-Vis spectra were recorded with a UV-1800 spectrophotometer (Shimadzu, Kyoto, Japan), with quartz (1-cm path length). All fluorescence measurements were performed on a 970CRT fluorescence spectrophotometer (Inesa, Shanghai, China) equipped with a xenon lamp source. All pH values were measured with a PHS-25 digital pH meter (Shanghai REX Instrument Factory, Shanghai, China).

¹H NMR and ¹³C NMR spectra were recorded on a Bruker Avance DPX 300 MHz instrument (Bruker, Billerica, MA 01821-3991, USA), TMS as the internal standard. ¹H NMR data are reported as follows: chemical shift, multiplicity (s = singlet; d = doublet; q = quartet; m = multiplet; br = broad), coupling constant (Hz), and integral. Data for ¹³C NMR spectra are reported in terms of chemical shift. Mass spectrometric data were obtained on Agilent Accurate-Mass-Q-TOF MS 6520 system equipped with an Electrospray ionization (ESI) source (Agilent, Santa Clara, CA 95051, USA). Specific rotations were obtained on a High Accurary Polarimeter Rudolph Autopl VI (Rudolph, Wilmington, Massachusetts 01887, USA). Toluene and DCM were freshly distilled after dried by calcium hydride under nitrogen, diethyl ether and THF were freshly distilled after dried by Lithium aluminum hydride. Unless otherwise stated, all reagents were commercially available and were used without purification. Organic solutions were concentrated under reduced pressure on a rotary evaporator or an oil pump. Reactions were monitored through thin layer chromatography (TLC) on silica gel-precoated glass plates (0.25 mm thickness, SiliCycle silica gel). Flash column chromatography was performed using Qingdao Haiyang flash silica gel (200–300 mesh).