Raman spectroscopy investigation of various saturated monoacid triglycerides

A study of the vibrational behavior of five saturated monoacid triacylglycerides is performed by Raman spectroscopy at room temperature in the 3100–500 cm −1 spectral range. The splitting of the C O stretching mode leads to conclude on the existence of two or three geometries of C O in the “knot” group O C O. The C O stretching mode seems to be a good tool for distinguishing the polymorphic forms of the studied triglycerides. The assignments of the different C H stretching modes are performed in the 1500–500 cm −1 spectral range. The I(2845)/ I(2880) (in the C H stretching spectral region) and I(1445)/ I(1296) intensity ratios (between the maximal intensity I(1445) of the CH 2 scissoring mode and the maximal intensity I(1296) of the skeletal vibration of (CH 2) n in-phase twist) seem to depend on the type of polymorphic forms of these molecules.