X-ray study of the structure and of the internal ordering degree in liquid α- and β-naphthalene derivatives

• Published in: Physics and chemistry of liquids 2007-04, Vol.45 (2), p.197-206
• Main Authors: Drozdowski, H., Błaszczak, Z.
• Format: Article
• Language: English
• Subjects: Differential radial distribution functions; Molecular ordering; X-ray diffraction in liquids
• ISSN: 0031-9104; 1029-0451
• DOI: 10.1080/00319100601106721

Structure and molecular correlations in liquid selected derivatives of naphthalene C 10 H 7 -R have been studied by X-ray diffraction and Fourier analysis. The compounds are obtained as a result of substitution of hydrogen atoms in the naphthalene molecule by a functional group R (in position α or β): R = Cl and CH 3 in chloronaphthalene and methylnaphthalene. The measurements of scattered radiation intensity were performed in a wide range of wave vector (S min  = 4.30 nm −1 to S max  = 153.10 nm −1 ), with the use of X-ray radiation MoK α (λ = 0.071069 nm). The mean parameters of the liquid structure (intra- and intermolecular distances, radii of spheres, coordination numbers) were found. A comparative analysis of these compounds has been made and the influence of particular functional groups (-Cl,-CH 3 ) and their position α or β in the ring on the molecular arrangement and packing coefficient has been discussed. The results of the study of molecular correlations in liquid α- and β-naphthalene derivatives may be important for explanation of mechanisms of certain physical and chemical processes taking place in similar systems, e.g., diffusion or thermal conductivity. The proposed experimental procedure and methods of data processing and interpretation can be used in investigation of other molecular liquids.