1600 spectrophotometer

FT-IR spectra were measured using a PerkinElmer 1600 spectrophotometer on pure solutions of (H1, H2 and H3) and those in which carbon steel sheets were immersed in 1 M HCl + the optimal concentration of each inhibitor for 24 hours.

Pods of Crotalaria cleomifolia were harvested in May 2014 at Manjakandriana, near Antananarivo (geographical coordinates, south: 18°54′06.9′′, East: 047°45′08.1′′). Seeds were separated from pods then dried at room temperature in the shadow. After drying, they were crushed in a fine powder using an electric grinder. Solvents used for the extraction were purchased from Cooper (Paris, France) and were used as received. Reagents used for the qualitative studies were purchased from Sigma-Aldrich (Saint Quentin Fallavier, France).
¹H and ¹³C NMR (1D and 2D) spectra were measured on a Bruker Avance 400 MHz (Mannheim, Germany) NMR spectrometer in CDCl₃ or CD₃OD. Chemical shifts are reported in parts per million (δ) and coupling constants (J) in Hz. The residual CDCl₃ or CD₃OD were used as internal standards for ¹H and ¹³C NMR, respectively. IR spectra were measured on a Perkin Elmer 1600 spectrophotometer. Optical rotations were measured at room temperature using a Perkin Elmer 343 Plus polarimeter. Electrospray ionization (ESI) mass spectra were recorded at the Institut de Chimie Moléculaire de Grenoble on a Waters Xevo G2-S Q TOF instrument (Guyancourt, France) with a nanospray inlet.

The FT-IR measurements of CAPE, β-CD,
Hβ-CD, and inclusion complexes were recorded using a PerkinElmer
1600 spectrophotometer in attenuated total reflection (ATR) mode.
The FT-IR spectra, ranging from 600 to 4000 cm^–1, were obtained with a resolution of 4 cm^–1, and
32 scans were used.^{30 (link)}