6220 accurate mass tof ms

LC-MS was conducted using a 1200 series system (Agilent, Waldbronn, Germany) consisting of an autosampler, degasser, binary pump, column oven, and diode array detector coupled to a 6220 accurate-mass ToF-MS (Agilent). A Hypersil Gold C₁₈ (150 mm × 2.1 mm, 3 μm particle size) was used as a column. Eluent A: H₂O/CH₃CN/HCO₂H = 95/5/0.1, and eluent B: H₂O/CH₃CN/HCO₂H = 5/95/0.1. The flow rate was 300 µL/min. The gradient was linear from 100% A to 98% B in 10 min; 1 min 98%; linear from 98% B to 100% A in 0.5 min; and 3.5 min at 100% A.

All materials were purchased from commercial sources and used without further purification. The ¹H NMR spectra were collected on a Varian MR-400 NMR spectrometer (Agilent, Santa Clara, CA 95051, USA) or a Bruker Avance III 600 MHz NMR spectrometer (Billerica, MA 01821, USA). ¹³C NMR spectra were collected on a Bruker Avance III 600 MHz NMR spectrometer. High Resolution Mass Spectra (HRMS/ESI+) were collected on an Agilent 6220 Accurate Mass TOF MS with an ESI source (Agilent, Santa Clara, CA 95051, USA). Solid-state Fourier Transform Infrared (FTIR) spectra were collected on a Midac M2000 FTIR spectrometer equipped with a DuraScope diamond ATR accessory (Midac Corporatyion, Westfield, MA 01085, USA). X-ray crystallographic data were collected at 100 K on an Oxford Diffraction Gemini diffractometer with an EOS CCD detector and Mo Kα radiation (Rigaku Americas Corporation, Woodlands, TX 77381, USA).