1H CRAMPS studies of molecular dynamics of a premium coal

Abstract Premium coal No. 601 supplied by the Argonne National Laboratory has been studied under extraction with perdeuterated pyridine. The proton CRAMPS technique was applied to the study of the molecular dynamics of the untreated coal, its evacuated residue following extraction and the extracted material. Saturation using deuterated pyridine improved spectral resolution, resulting in the identification of two aliphatic resonances (0.9 and ≈1.7ppm) and three aromatic resonances (≈6.9, ≈8.1 and ≈9 ppm). The CRAMPS dipolar dephasing experiment showed that the spectral intensity decay consists of two or possibly three components, which can be described by a combination of Gaussian and/or Lorentzian curves. The initial amplitudes of these components and their respective decay time constants are changed with extraction. A correlation between the behaviour in the dipolar dephasing experiment and the molecularmacromolecular structure of coal is observed.