IR spectroscopy of coal 1. Difference in DRIFT spectra of coal in repeated measurements

Polyene model of coal structure

“…By means of IR diffuse reflection spectroscopy of coal [46][47][48][49] and spectral subtraction, structural data consistent with the existence of cis and trans forms were obtained [50]. Further, it was suggested that methylene groups are present in the polyene chain, while carboxyl groups predominantly take the form of dicarboxyl chelate structures [50].…”