Molecular ordering in some liquid aromatic hydrocarbons

Abstract

This study presents a comparison of the structures and molecular correlations for the linear aromatic hydrocarbons: benzene, naphthalene, and anthracene in the liquid phase, performed for the first time by the method of X-ray diffraction. Also for the first time the X-ray diffraction results obtained for anthracene at 513 K have been reported. Monochromatic radiation CuK_α was used to determine the scattered radiation intensity between S _min = 4π sin Θ_min/λ = 0.417 Å⁻¹ and S _max = 4π sin Θ_max/λ = 7.06 Å⁻¹. The mean angular distributions of X-ray scattered intensity were measured and the differential radial distribution functions of electron density (DRDFs) were calculated. The mean distances between the neighbouring molecules and the mean coordination numbers were found. The most probable models of local ordering of these molecules were suggested. Correlations have been found between the number of benzene rings in the molecules studied and their physical properties.

Keywords:

• X-ray diffraction
• Molecular ordering
• Aromatic hydrocarbons

Acknowledgement

This work was performed within research project No. 2P 302 006 04 of the Committee for Scientific Research (Republic of Poland).