Structural study on polymorphism of long-chain dicarboxylic acids using oblique transmission method for micro FT-IR spectrometers

摘要: Polymorphism and higher-order structures of even-number dicarboxylic acids from hexadecanedioic acid to eicosanedioic have been studied by micro-FTIR spectroscopy microscopic observation. In order obtain the three-dimensional structural information, oblique transmission method was incorporated into a spectrometer equipped with couple Cassegrain lenses. The IR spectra showed that solid states bore marked similarity those n-saturated fatty acids. It found solution-grown single crystal an aggregate lamellae whose thickness exceeded far their molecular length. surfaces were covered hydrocarbon segments taking hairpin structure, linkage hydrogen-bonded formed folded chain structure. result measurements stacking mode varied depending on crystallization conditions.