Nicolet avatar ft ir spectrometer

NMR spectra were recorded on a Varian 500 spectrometer (Palo Alto, CA, USA) in DMSO-d₆ or in MeOD, at 500 MHz (¹H) and 125.68 MHz (¹³C); chemical shifts are in ppm (δ) with DMSO (δ = 2.50 for ¹H-NMR and 39.50 for ¹³C-NMR) or with MeOD (δ = 3.34 for ¹H-NMR and 47.60 for ¹³C-NMR) as the reference. Coupling constants J are given in Hertz. ¹H and ¹³C-NMR resonances were assigned using a combination of DEPT, COSY, and HSQC spectra. Infrared (IR) spectra were recorded as thin film or Nujol mull on NaCl plates on a Nicolet Avatar FT-IR spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). Melting points are uncorrected. Electrospray (ESI) mass spectra were obtained on a Bruker Daltonics Esquire 4000 spectrometer (Billerica, MA, USA). HRMS were obtained on a Bruker micrOTOF-Q. Fluorimetric assays were run on a Perkin Elmer LS50B spectrofluorimeter (Waltham, MA, USA). Yields refer to spectroscopically (¹H-NMR) homogeneous materials. Commercial reagents and solvents were purchased from Sigma-Aldrich.