Frontier optica ftir spectrometer

Melting points were measured on a Buchi melting point B-540 visual thermometer. The optical rotations were measured with a Bellingham and Stanley APD440 polarimeter. The UV spectra were recorded with a Perkin Elmer UV-Vis spectrophotometer. Infrared (IR) spectra were recorded using a Perkin Elmer Frontier Optica FT-IR spectrometer. Electronic circular dichroism spectra were recorded on a JASCO J-815 spectrometer. The NMR spectra recorded using 400 MHz Bruker FT-NMR Ultra Shield and 600 MHz Bruker AV-600 spectrophotometers. The HRESITOFMS were obtained on a Bruker microTOF mass spectrometer and Bruker-Hewlett-Packeard 1100 Esquire-LC system mass spectrometer. The HREIMS were recorded using Kratos MS-50 mass spectrometer. Chiral HPLC was performed on a CHIRALPAKIA 15 column of 10–250 mm and attached to Waters 2487 Dual λ absorbance detector.

The PerkinElmer Frontier Optica FTIR spectrometer (PerkinElmer, Norwalk, CT, USA) was used to collect FTIR spectral data of the samples using a previously described method (Wang et al., 2020 ). The parameter was set to point mode to collect the reflection spectrum, and the spot size was 50 μm × 50 μm. The resolution was 8 cm⁻¹, scanning speed was 1.0 cm s⁻¹, scanning interval was 2 cm⁻¹, scanning range was 5005–1000 cm⁻¹, and number of background scanning times was 100. Each sample was scanned twice, and the spectral data were stored in the form of absorbance. Spectrum IMAGE Software from the “stats” R package (Śliwińska, Wiśniewska, Dymerski, Namieśnik, & Wardencki, 2014 (link)) was used for spectrum acquisition and spectral data processing; the drawing and modeling program codes were prepared by us. Before the experiment, corrections were conducted to reduce the experimental error caused by atmospheric interference and instrument noise.